Vol. 52, No. 2 Physics in Canada March/April 1996 La Physique au Canada mars/avril 1996

FEATURING:

I The Physics of Dilute 2D Electron and Hole Systems in Si-Based Heterostructures by M. D'lorio Nouvelle source de plasma pour le traitement des matériaux: Magnétoplasma à onde de surface by J. M argot Evaluation of the Acid Deposition and Oxidant Model with Ozone and Sulphur Dioxide Data from High Elevation Sites by C. Banic et al Contrôle des modes latéraux de lasers à semi-conducteurs: Expériences et simulations by N. McCarthy et al Symmetry-Violating NN Potentials in the Nucleus WOMEN PHYSICISTS IN CANADA by A.C. Hayes LES PHYSICIENNES AU CANADA Outflows from Spiral Galaxies (nu) byJ.A. Irwin 2100.0 lll-V Semiconductor Characterization I for Optoelectronics j by C. Miner and, in the PHYSICS AND EDUCATION SECTION: 2212.5 The Early History of Women in Univ. Physics: A Toronto Case Study by A. Prentice Using Nonsexist Language/Rendering 2325.0 the CAP By-laws Gender Neutral by R. King and D. Poirier Women Physics Faculty in Canada by J. Lagowski and J. McKenna 2437.5 Women Students in Physics in I Canada: A Decade of Progress by A. McMillan and E. Svensson WES - Women in Eng. and Science: 2550.0 A Canadian Success Story at NRC by M. D'lorio The Committee on the Status of Women in Physics of the American Physical Society by L. Martinez-Miranda Individual and Family Profiles

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GLASSMAN U.S.A. GLASSMAN EUROPE GLASSMAN JAPAN Classman High Voltage, Inc. Glassman Europe Limited Glassman lapan High Voltage Limited P.O. Box 551 21 Campbell Court Taira Building Whitehouse Station, N| 08889 Campbell Road 1-17, Taira 1-chome USA. Tadley Miyamae-ku, Kawasaki 216 Telephone: (908) 534-9007 Bramley lapan FAX- (908) 534-5672 Hampshire RG26 5EG Telephone: (044) 877-4546 England FAX. (044) 877-3395 In Canada: (514) 455-7408 Telephone: (1256) 883007 FAX: (514) 455-7387 FAX: (1256)883017 CANADIAN ASSOCIATION ASSOCIATION CANADIENNE OF PHYSICISTS DES PHYSICIENS ET PHYSICIENNES

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WE

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MOVING!!

E ffective 1996 May 14, the Canadian Association of Physicists can be reached as fo llo w s:

BY M AIL Suite 11 2 (or in person) McDonald Building 150 Louis Pasteur Ave. OTTAWA ON K1N6N5

BY TELEPHONE (613) 562-5614

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We look forward to our continuing interactions with you. CANADIAN ASSOCIATION ASSOCIATION CANADIENNE OF PHYSICISTS DES PHYSICIENS ET PHYSICIENNES

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NOUS

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Le 14 mai 1996, l'Association canadienne des physiciens et physiciennes occupera ses nouveaux locaux dont les coordonées sont les suivantes:

ADRESSE POSTALE Bureau 11 2 (ou en personne) Immeuble McDonald 1 50, rue Louis Pasteur OTTAW A ON K 1 N 6 N 5

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Au plaisir et à bientôt. Vol. 52, No. 2 Physics in Canada_____ March/ April 1996 La Physique au Canada mars/avril 1996

INDEX FEATURE NON-TECHNICAL ARTICLES: Pages 50-52 Pages 94-96 (cool'd ou pg. 100) Editorial and Calendar/Calendrier The Early History of Women in University Physics: A Toronto Case Study Pages 53-57 by A. Prentice Science Policy Update / Mise à jour sur la politique scientifique Pages 97-100 Pages 58-60 Using Nonsexist Language/Rendering the News / Nouvelles CAP By-Laws Gender Neutral / ’L'utilisation University News / Échos des Universités d'un tangage non-aexiste/La modification de ta International News / Nouvelles Internationales constitution de i'ACP pour te rendre non-sexiste by R. King and D. Poirier Page 61 Pages 1 0 6 -1 0 7 (ooot'd oo pg. 112) Canadian Physicists / Physiciens et Physiciennes Canadien(nejs Women Physics Faculty in Canada News from Corporate Members by J.B. Lagowski and J. McKenna

Pages 1 0 8 -1 1 0 (corn'd oo pg. 113) Women Students in Physics in Canada: A FEATURE TECHNICAL ARTICLES: Decade of Progress Pages 62-68 (coat'd od pg. 71) by A.C. McMillan and E. Svensson The Physics of Dilute 2D Electron and Hole Systems in Si-Based Heterostructures Pages 111-112 by M. D'lorio WES - Women in Engineering and Science: A Canadian Success Story at NRC / PIC - Pages 69-71 Programme d'ingénieures et chercheuses: Un Nouvelle Source de Plasma pour le traitement des matériaux: Magnétoplasma programme canadien couronné de succès au CNRC by M. D'lorio à onde de surface by J. Margot Page 113 The Committee on the Status of Women Pages 72-76 (cont'd o d PR 80) in Physics of the APS Evaluation of the Acid Deposition and Oxidant Model with Ozone and Sulphur by L. Martinez-Miranda Dioxide Data from High Elevation Sites by C.M. Banic at al Pages 114-126 Individual and Family Profiles by i. Condroa; Pages 77-80 N.R. Evans; D. Pinsonneault; D. Poirier; M. Hilts, Contrôle des modes latéraux de lasers à semi-conducteurs: Expériences et C. Lucas, S. Ghosh and C. Klatt; M.A. White; A. Hayes simulations and S. Sterbenz; J. Berlinsky and C. Kallin; J. and M. Thewalt; end Y. Qj by N. McCarthy at al

Pages 81-85 (coot’d o d pg. 89) Page 102 Symmetry-Violating NN Potentials in the Nucleus Institutional Members / Membres institutioneis by A.C. Hayes Sustaining Members / Membres de soutien Pages 103-105 Pages 86-89 The CAP 1994 Income Survey Outflows from Spiral Galaxies by J.A. Irwin Pages 127-129 Books Received i Livres reçus Pages 90-93 Book Reviews / Revues des livres lll-V Semiconductor Characterization for Optoelectronics Page 130 by C.J. Miner Ads Inside Back Cover Printing: Love Printing Service Ltd. Corporate Membres / Membres corporatifs

Advertising R a tes Single Issue O n e -Y e a r E f f e c t i v e January 1996 Jan., March, July, Congress Issue C o n tra c t FRONT COVER: Fig. 2, "lll-V Semiconductor Sept., Nov. (M a y ) (6 issu e s) Full P age $ 6 6 0 . 0 0 $ 6 1 0 . 0 0 $ 4 6 0 . 0 0 Characterization for Optoelectronics” by H a lf Page 4 2 0 . 0 0 4 6 0 . 0 0 3 6 0 .0 0 C.J. M in e r (pg. 90). (Top) The reflectance at a Quarter Page 2 4 6 .0 0 2 7 0 .0 0 2 1 0 . 0 0 Fourth Cover 7 0 6 . 0 0 7 7 6 . 0 0 6 0 0 .0 0 wavelength of 1000 nm is displayed for an InP layer Second & Third Cover 6 1 0 . 0 0 7 0 6 . 0 0 6 1 0 . 0 0 grown on an In MGa 47As marker layer. (Bottom) W ith Colour, $228.00 each additional colour; Bleed $140.00 the additional information inferred from at least one Typesetting and art tim e extra Deadline for Copy - 16th of previous month reflectance spectrum for each fringe, the sRS map can Published -Jan/Feb., March/Apr., Msy/June, July/Aug.. Sept/Oct., Nov/Dec. be translated to this thickness map. EDITORIAL -

It is an honour to be the first woman invited to be the special editor of Physics in Canada, in particular for a special issue on Women Physicists. I made a presentalion at the CAP The Bulletin of Congress on the subject of "Women in Physios - a Matter of Education" in Edmonton in The Canadian Association 1 986. Thus, it is especially interesting for me to revisit the subject of woman physicists of Physicists after a decade and a particular delight to present this special issue of Physics in Canada celebrating their contribution and presenting their view of physics in Canada. However, it is Bulletin de l'Association with some trepidation that I write an editorial on this subject. Special editors that have not "stuck to their knitting” have not received particularly gentle treatment in Canadian physics canadienne des journals in the past. physiciens et physiciennes "Woman physicist"....some feel that this expression is an oxymoron. On the other hand, EDITORIAL BOARD / many people, indeed many women, feel that barriers for women who want a career as a COMITÉ DE RÉDACTION physicist have been effectively dealt with through policies on maternity leave, wider access to day care, universal medical benefits and the like. "Suffragettes" of yesteryear who Editor / Rédacteur en chef chained themselves to fences to win the vote for women would undoubtedly be amazed to J.S.C. McKee see the changes in today’s world in which it is possible for women to integrate career and Accelerator Centre family life in a seamless way. Yet, the survey of university physics departments reported on Physics Department in this issue indicates that only 1 3% of Canadian PhD students in physics are women and University of Manitoba Winnipeg, Manitoba R3T 2N2 there remain major university physics departments which have no female faculty members. (204) 474-9874; Fax: (204) 269-8489 e-mail: [email protected] Indeed, there has been substantial cultural change in Canada with respect to the role and position of women. "Women in Canada, A Statistical Report" released by Statistics Canada Associate Editor / Rédactrice associée in August, 1995, summarizes the status of women in Canada in the early ninetys. There is F.M. Ford good news and not so good news. There has been an increase in the participation of Managing / Administration women as university students in general. In the 1992-93 academic year, women accounted Book Review Editor / Rédacteur à la for 52% of all full time university students. In some scientific disciplines representation of critique des livres women has increased dramatically. In 1994, women made up 32% of all doctors and A. Roberge dentists, up from 18% in 1982. An education pays. While at all levels of educational Dept, of Physics and Astronomy attainment women’s earnings remain lower than those of men, female university graduates Laurentjan University employed full-time, earned 75% as much as their male colleagues in 1993, while the Sudbury. ON P3E 2C1 (704) 675-1151x2234 average pre-tax income of all women aged 1 5 and over was only 58% of the average e-mail: [email protected] income of men. The employment rate of women increases dramatically with educational attainment. In 1994, 77% of female university graduates as compared with 82% of male Advertising Manager graduates were employed. M. Steinitz Dept, of Physics There is also some not so good news for women. This same report says that in 1 982, 1 5% St. Francis Xavier University P.O. Box 5000 of professionals employed in the natural sciences, engineering and mathematics were women Antigonish, Nova Scotia B2G 2W5 and in 1994 this has risen to only 19%. Though women do make up more than half of full (902) 867-3909 time university students, in 1992-93 women made up just 35% of those working full time Fax; (902) 867-5153 toward their doctorates. In 1 994, 70% of all employed women worked in teaching, nursing e-mail: mstein it@ju I iet.stfx.ca and related health occupations, clerical positions, or sales and service occupations compared to 31 % of men. Thus, many women continue to pursue career paths that are traditional to J.G. Cook Institute for Microstructural Sciences them, and physics is not one of these. It is interesting to reflect on these statistics in the National Research Council (M-50), context of Alison Prentice's article on women in physics decades ago in Canada. Montreal Rd , Ottawa, Ontario K1A 0R6 These dry statistics show that while advances have been made over recent decades, for (613) 993-9407 whatever reason, there are career differences between women and men which persist in our Fax: (613) 957-8735 culture. Reasons are too many to explore here and the discussion could become long, and Béla Joos riddled with non scientific opinion and debate. The facts speak for themselves. University of Ottawa Ottawa, Onl. K1N6N5 The objective of this issue is to present an overview of woman physicists in Canada as we (613) 564-3460 Fax:(613) 564-6712 approach the end of the millenium. As you will see, we have much to celebrate in the e-mail: bjosj@acadvm 1 .uoftawa.ca contributions of women to physics in Canada. As you will also see, these contributions go far beyond the intellectual...the presence of these women is beginning to strengthen the Terry J. McKee Lumonics inc. fabric of our profession and to stretch it, as some of the profiles of student, married couples 105 Schneider Road and newcomers to Canada illustrate. Kanala, Ont. K2H 8C3 (613) 592-1460 The Canadian Association of Physicists has supported a Committee to Encourage Women in Fax: (613) 592-5706 Physics (CEWIP) since 1983. Interestingly enough, the committee was initiated by men and R.H. Packwood has been supported by them throughout its history. The "two Jim's" as they have come to Metals Technology I aboratories be affectionately known are Jim Prentice and Jim Megaw. Both now retired, these two F-M-R acted as mentors and examples for many women who participated in the committee over 568 Booth St., Ottawa, Ont. (613) 992-2288 the past decade. Remarkably, it has been men who like women and respect their I ax; (613) 992-8735 contribution to the community who have made the committee workable. In the early years, Mona Jento, then Secretary of the CAP and herself a science graduate and pioneer, was an ANNUAL SUBSCRIPTION RATE/ABONNEMENT ANNUEL $3 7.45 (domestic) / $40.00 (foreign) active supporter and participant. A major problem has been getting women to become ADVERTISING. SUBSCRIPTIONS. involved with the committee and to take on work associated with it. The common thread is CHANGE OF ADDRESS. PUBLICITÉ, ABONNEMENT. that women have too much to do. CHANGEMENT D ADRESSE: Canadian Publications Product Sales Agreement No, 0484202/ Envois de publications The current chair of the committee is Debbie Poirier, whose profile is featured in this issue. canadiennes numéro de convention 0484202 Please provide comments and advice on the direction of the committee to her. Her e-mail

Canadian Association of Physicists/Association address is canadienne des physiciens et physiciennes Bur ./Suite 112, Imm. McDonald Btdg. 150 Louis Pasteur The CEWIP has been a truly national committee with corresponding membership of about 20 Ottawa, ON KIN 6N5 people from coast to coast. Each individual member of CEWIP undertakes their own slate of Tel: (613) 562 5614 e-m ail: CAPtâphysics.uottawa.ca activities which typically include career talks, collection of information ori some aspects of Fax/Téléc: (613) 562-5615 the issue, or liaison with other organizations interested in women in science. For, example Jim Megaw undertook a survey of all the universities in the world to obtain data

50 Physics in Canada March/April I 996 about the participation rates of women in according to the APS, if they marry, marry physics and reported on "Gender men in science (see Anna Hayes' and Discrimination in the World's Physics Steve Sterbenz' profile for numbers). The ERRATUM Departments" at the Gender and Science women are typically somewhat younger and Technology meeting in Australia in than the men and hence not as far along in 1991. The committee has undertaken their careers when they enter the marriage. In the "Ph.D. Degrees Awarded at some additional specific actions: Thus, w hen a fam ily is desired, it is likely Canadian Universities in 1995" to make excellent sense for the woman to - Until 1987 there had rarely been a give up or postpone her career. section of the 1996 woman on the CAP Lecture Tour. In Unfortunately, many of these highly January/February issue of Physics in order to change this situation, names of competent and enthusiastic women never outstanding woman speakers were return to the field. On top of all the Canada Abdul Elezzabi was included (with the Education Division's domestic issues they must deal with, there inadvertently listed as currently at a permission) on the CAP list for several are a host of rules against nepotism, etc, years. Inevitably the women received that can limit a woman's opportunity to Post Doctorate Fellowship at the more speaking invitations on average find suitable employment in the same University of Edmonton. This entry than the men. Mary Anne White, whose geographical area as her husband. This profile appears herein, was one of the issue arises again and again in the should have read the University of first and most popular. Lately, the statements provided by women in this Alberta. Our apologies to all current departments have been nominating issue. Solutions range from long range woman speakers directly. commuting to challenging the system. and former graduates/employees of Unfortunately, whatever the solution it is the University of Alberta for this A Directory of Women in Physics in likely to have ongoing impacts on the Canada has been developed. This woman's happiness and her career, not to error. directory is now with the CAP office mention her family. It is clear that one for use by potential employers, seekers piece of advice that should be passed on of graduate students. The committee is to women students is to ensure that the looking for someone to take on the man she marries is supportive of her continued responsibility of updating the maintaining a career. That support can be list and ensuring its availability. crucial to ensuring increasing participation of women in the physics community. Meetings are held several times a year, Understanding the issue can help the always at the CAP Congress in physics community deal with such couples whichever city it occurs and, in a more humane way. additionally, in Quebec or Ontario. There was a women's session at CAM Please read on and enjoy. We are 95 in Quebec City which included interested in your response to this issue. Mexican and American physicists. Dr. Ann C. McMillan The Canadian committee has chosen a low Guest Editor keyed approach to the equity issue and tries to weave a thread of consciousness about the issue into the business of the CAP. The APS has taken a more high profiled approach and some of their excellent Additional Reading Suggested by our Readers: programs are described in this issue.

This issue takes the Canadian approach. A Passion for Physics - The Story of a scientists? Other than Madame Curie, I We have no strident demands to present. Woman Physicist can't think of any," which expressed an We do have an overview of the Joan Freeman attitude that was even more prevalent tremendous present and potential future IOP Publishing, Bristol, England 1991 before this book was published. contribution of women to physics in Carol Herzenberg Canada. We have a collage of technical Another source of information is an writings over a broad selection of fields, international reference listing and some nontechnical papers on a variety of biographical directory of some notable topics related to women, and some profiles women scientists from ancient to modern Women Scientists in America: Before of woman physicists and physics couples who say in their own way what physics is times. "Women Scientist from Antiquity Affirmative Action 1940-1972. By Margaret all about in Canada today. These profiles to the Present: An Index" was published W. Rossiter, John Hopkins University Press: capture the enthusiasm and creativity of by Locust Hill Press, West Cornwall CT in 1995. woman physicists and although none of 1986, and is available from the publisher them highlight major issues within the and is in most major university libraries. It D. Poirier community, some common themes includes women in mathematics, medicine, INRS emerge. The one that emerges most and engineering; there are over 2500 clearly has little to do with overt barriers or individual entries that will help you locate discrimination. It is the difficulty of further biographical information on all of managing dual careers in physics. In today’s tough economic climate it is these women. You may find this book difficult to manage one science career. It useful - it was developed in part to is not surprising that it is vastly more respond to such statements as "Women difficult to manage two. Numbers are part of the issue here. Most women in physics.

La Physique au Canada mars à avril 1996 51 CALENDAR / CALENDRIER 1996 JUNE TO 1997 JUNE information, please contact: WL, Pinawa, Manitoba, ROE 1L0. Tel: A. Donszelmann at Tel: +31 (20) (204) 753-2311 ext 2592.22-26 Combinations and Group Theory 5256334, Fax: +31 (201 525 5102, The Centre de recherches e-mail: [email protected] 21- 26 European Research Conference on mathématiques is hosting a year-long Quantum Optics, K. Burnett (Oxford) - program in combinatorics and group 11-23 CRM Summer School/Combinatories Castelvecchio Pascoli, Italy. More theory in 1996-97. The year will be and Group Theory, Banff, Alberta. For information can be obtained on the organized around a certain number of more information contact: CRM World Wide Web server at: workshops spread throughout the year. Summer School, CRM, Université de http:Wwww.esf.org For a schedule of events, please Montréal, CP 61 28, Suce. Centre-ville, contact: Louis Pelletier,CRM, Université Montréal, QC, H3C 3J7, e-mail: 22- 26 Physics and Industry (PHYSIN-96), de Montréal, CP 6128, Suce. Centre- [email protected], Fax. Nyzhny Novgorod (Russia). For more Ville, Montréal, QC, H3C 3J7 or e-mail (514) 343-2254, Tel: (514) 343-2197 information please contact: Euro-Asian to: [email protected]; Physical Society, 17, Kursovoj bystr., WWWhttp://www.CRM.UMontreal.CA 17-24 8th International Organization of Moscow, 119034, Russia. Tel: (095) Science and Technology Education 943-7677; Fax: (095) 943-7686, 1996 JUNE______(I0STE) Symposium, Edmonton, e-mail: [email protected]. 7- 11 European Research Conference on Alberta. For more information, please Fundamental Aspects of Surface contact: Continuing Professional 24-26 BEM 18: 18th International Conference Science: Semiconductor Surfaces, C. Education: Faculty of Education, on Boundary Element Methods, Braga, Sebenne (Paris) - Blankenberge, University of Alberta, 4-116 Education Portugal. Abstract deadline Belgium. More information can be North, Edmonton, Alberta, T6G 2G5, December 18, 1995. Final paper due obtained on the World Wide Web server Tel: (403) 492-0394, Fax: (403) 492 April 29,1995. Sponsors: International at: http:Wwww.esf.org 0390. Society for Boundary Elements, for more information contact Liz Kerr, 9-12 CNA/CNS Annual Conference, New 19-23 17th General Congress of the Wessex Institute of Technology, Brunswick. For more information, International Commission for Optics, Ashurst Lodge, Ashurst, Southampton please contact: Ms. Tatiana Wigley, Taejon, Korea. Theme: "Optics for SO40 7AA, UK. Tel: (44)11703) CNA/CNS Office, Toronto Ontario. Tel: Science and New Technology". For 293223, Fax: (44)11703) 292853, (416)977-6152; Fax: (416)979-8356. more information, please contact: ICO- E-mail: [email protected]. 17C96) Secretariat, Prof. B.Y. Kim, 16-19 CAP Annual Congress, University of Department of Physics, KAIST, 1996 SEPTEMBER ______373-1 Kusong-dong,Yusong-gu,Taejon Ottawa, Ottawa, Ontario. For Congress Sept. 28 Information see 1996 January/February 305-701, Korea. Tel: +82-42-869­ Oct. 3 European Research Conference on Physics in Canada or Congress section 2527; Fax: +82-42-869-5527. Chaotic Phenomena in Nuclear Physics of Univ. of Ottawa home page at S. Aberg (Lund) - Aghia Pelagia, Crete, http://www.physics.uottawa.ca/ 27-30 2nd International Conference on Greece. More information can be hyperons, charm and beauty baryons, obtained on the World Wide Web server 1996 SUMMER______Concordia University, Montreal, at: http:Wwww.esf.org Quebec. For more information, please Physics in Industry International contact: Lynn Chapman-Baker, Physics Conference, Nyzhny Novgorod, Russia. Dept., Concordia University, Montreal, 1997 JULY ______For more information, please contact: QCH3G1 M8;Beauty@vax2. Concordia, 1-7 Joint Scientific Assemblies: Professor S.P. Kapitza, Euro-Asian ca International Association of Physical Society President, 17 Kursovoy, Moscow 119034, Russia. Meteorology and Atmospheric Sciences 1996 SEPTEMBER______/ International Association for the Fax: (095) 943-76-77; E-mail: [email protected]. Physical Sciences of the Oceans, Aug.31 European Research Conference on Melbourne, Australia. For more Sept. 5 Advanced Quantum Field Theory: information, please contact: 1996 JULY______Integrability, Conformal Invariance, IAMAS/IAPSO Secretariat, Convention Topological Field theory and 8- 10 Third International Workshop on Laser Network, 224 Rouse Street, Port Applications, V. Rittenberg (Bonn) - La Beam and Optics Characterization / 3* Londe-les-Maures, France. More Melbourne Victoria 3207 Australia. Tel: Atelier international sur la caractérisa­ + 61 3 9646 4122; Fax: +61 3 9646 information can be obtained on the tion des faisceaux et de l'optique laser, 7737; e-mail: [email protected]. World Wide Web server at: Québec, QC. Pour plus d'information, http:Wwww.esf.org veuillez contacter Michel Morin, Institut 25th International Cosmic Ray national d'optique, 369, rue Franquet, Conference, Durban, South Africa. For 9-1 3 EPS 10 Trends in Physics, 10th General Sainte-Foy, QC, Canada, G1 P4N8, Tel: more information contact: National Conference of the European Physical (4181 657 7006, Fax: (418) 657-7009; Organizing Committee 25th ICRC, Society, Sevilla, Spain. For more cour.élec: [email protected]. Space Research Unit, Department of information, please contact: Organizing Physics, Potchefstroom University for 1996 AUGUST______Secretariat, Proconsur, Avda. San Che, Potchefstroom 2520, South Francisco Javier n° 15, 4°, E-41018 Africa. Tel: +27-148-2992423, 5-9 Zeeman-Effect Centenary/ International Sevilla (Spain) Tel: (34-5) 492 27 55 Fax: +27-148-2992421, E-mail: Conference on Atomic Physics XV [email protected],AC.ZA (ZICAP), Van der Waals-Zeeman 16-19 Deep Geologic Disposal of Radioactive Laboratory, University of Amsterdam, Waste, Winnipeg, Manitoba. For more Valckenierstraat 65, 1018 XE information, please contact: Amsterdam, The Netherlands. For more Mr. C. Vandergraaf, AECL Research -

MARK YOUR CALENDARS - FUTURE CAP CONFERENCES -

CAP 1997 Annual Congress, 1997 June 8-11, University of Calgary.

CAP 1998 Annual Congress, 1998 June 14-17. University of Waterloo.

Any universities interested in hosting a CAP Annual Congress can send a letter of interest to the CAP Office, Bur./Suite 112, Imm. McDonald Bldg., 150 Louis Pasteur, Ottawa, ON K1N 6N5. The letter should include an indication of what year you are interested in, keeping in mind that the Congress travels Central-East-Central-West.

52 Physics in Canada March/April 1996 SCIENCE POLICY UPDA TE / MISE A JOUR SUR L A POLITIQUE SCIENTIFIQUE

At the start of his term as CAP These are: marketplace, Gerrard referred to President, P.S. Vincett stated that the programs such as the new NRC-NSERC most important task for his Presidency 1. That any science policy have as a Industry partnerships and the Western would be (with the help of many others) goal the creation of a sustainable Diversification Fund initiatives. We to establish CAP as a truly effective distribution of effort between basic stressed the fact that it is still voice for science, one which would science, applied science, extremely difficult for small knowledge- speak to governments clearly and development and commercialization based companies to obtain funds for effectively on behalf of physics and of of the developments. new ventures. science as a whole. After an enormous amount of effort, it appears that this is 2. A major impediment to the The effect cuts to the transfer becoming a fact; there are many in commercialization of Canadian payments will have on research Ottawa who would now tell you that research and development is the infrastructure at universities was also the CAP is one of a handful of leading reluctance of our financial raised. Gerrard pointed out that the voices for science both nationally and in institutions to provide financing for federal government does not get credit many provinces. Now that the CAP has late-stage development and initial for the funds it invests here. the resources and expertise in place, producation of new products of P.S. Vincett believes that the CAP can small and medium sized enterprises. Gerrard advised us that the report on play a critically important role in the While the government has recently the federal S&T Review was to be challenges which continue to face announced several programs to released with the budget. His physicists, whether they be in a address this problem, it should be Department will hold briefings on the university setting or elsewhere. The recognized as an on-going challenge report for CAP, CSC and other CAP must speak for physics as a requiring additional responses. organizations. w hole. Productive Meetings with Government The effects of the cuts to the transfer A report on science policy activities payments on the research capability of undertaken recently follows. This year the CAP joined with the universities were also discussed with Comments and suggestions are invited Chemical Society of Canada (CSC) to Peter Adams, M.P., Chair of the Caucus from CAP members. Please direct them conduct the first joint lobby effort. The Committee on Higher Education. Adams to F.M. Ford, Science Policy Officer, mid-February meetings with said his Committee was formed to Canadian Association of Physicists, Jon Gerrard, Minister of State for address higher education issues and S u ite 112, McDonald Building, Science, Research and Development, realizes the impact of these cuts. 150 Louis Pasteur Ave., Ottawa, and other government officials were Adams said that teaching is the more Ontario, K1N 6N5; email attended on behalf of the CAP by obvious product of universities and [email protected] . Paul Vincett, President; Bev Robertson, research is less visible. Although he Vice-President; Don McDiarmid, pointed out that it was then probably Director of Professional Affairs; and too late to influence the upcoming LOBBYING Francine Ford, Executive Director. CSC budget, he did feel that immediate representatives included President Ron action may influence future strategy. Steer; Vice-President Vedene Smith, On his advice, the CAP and the CSC National Consortium and Executive Secretary Anne Alper. Presidents wrote to the Prime Minister urging that he give some indication in The CAP wrote most of the briefing Discussions with Gerrard focused on the Speech from the Throne on how paper on the Importance of Research the long overdue report on the federal this will be addressed in the longer which the National Consortium of Science and Technology Review, how term. The CAP’S letter was distributed Scientific and Educational Societies advice on science and technology is to CAP members by email on 1996 used in their meetings with a large provided to government, the effect of February 20. Subsequently a signifi­ number of Ministers and senior civil the cuts to the transfer payments on cant number of CAP members wrote servants in November/December 1995. university research and the need for similar letters to the Prime Minister This paper focused on the importance resources to bring proven technology to expressing their concern over the of the whole spectrum of research, and the marketplace. current situation and urging a national particularly emphasized the importance solution in the longer term. Adams also of long-term work. Gerrard emphasized the need for urged our organizations to bring the independent advice on science and message about the importance/exis- The Consortium recently asked its technology issues. He said that the tence of university research to the MPs members for input regarding a science lobby is diverse and not well in their local ridings. In a later meeting, Consortium science policy. versed in w h a t is possible in Adams stated that the follow-up to D. McDiarmid, Director of Professional government. He urged the scientific these meetings by the physicists and Affairs, felt, in consultation with community to take the initiative and the chemists has been very impressive. P.S. Vincett, that from the CAP'S point create a structure for providing of view there are two issues which we coherent, clear advice to government. The need for science and technology to feel must, among others, be part of any have a higher priority on the govern­ Consortium science policy document. With respect to the need for resources ment's agenda was raised in all our to bring proven technology to the meetings. Arthur Carty, FCIC, President

La Physique au Canada mars à avril 1996 53 of the National Research Council, said need for the science community to Martha Piper, University of Alberta, that this will not happen until people are develop a mechanism for giving advice Vice-President (Research and convinced of the value of S&T. He sees to government. External Affairs) an important role for scientific societies in building science awareness with the Hull expressed concern about the future Elizabeth Cannon, University of public. Without this, future cuts to S&T viability of the Canadian university Calgary, Department of Geomatics budgets are inevitable. system and the ability of universities to Engineering cope with current cutbacks and address Carty said that the government new challenges, such as education Ron Steer, University of Saskatchewan, priorities are jobs and growth. We must supplied to Canadians from abroad Department of Chemistry work with industry to convince using computer networks. government of the role of science in Bev Robertson, University of Regina, this process. He said that a recent Department of Physics study has shown that the IRAP Program Lobbying Can Have Results - University created 9,000 new jobs and saved Advisory Committee Katherine Schultz, University of 6,000 existing jobs. Funding for IRAP Winnipeg, Associate Vice-President sunsets in 1998-99 and he would like Usually one expects lobbying to be a (Research and Graduate Studies) our assistance in publicizing the value long-term process with little of of the program. immediate interest to report. This does Heather Munroe-Blum, University of not appear to be the case for the Toronto, Vice-President (Research The Economic Policy Secretariat in the CAP/CSC lobby effort in mid-February. and International Relations) Department of Finance provides advice Following the meeting with Doug Hull to the Minister of Finance on and some of his staff at Industry Bruce Hutchinson, Queen's University, macroeconomic policy and program Canada, Bev Robertson, CAP Vice­ Director of Research Services design and development including President, received a call from advice on proposals brought forward by Sue Milne of the University Liaison R o g e r Lecomte, University of other Ministers. Peter Cameron, Group Section of Industry Canada in early Sherbrooke, Department of Nuclear Chief, Industry, Regional and Corporate March. The discussions with CAP/CSC Medicine and Radiobiology Policy in this Department, said there is triggered the establishment by Industry a large science and technology effort Canada of a consultative group of Gilles Delisle, INRS Telecommuni­ currently in government departments university people. cations, Directeur de centre de which, with the thrust of the present recherche government, he sees as moving to the The University Advisory Board will be private sector. The current low level of providing advice to Doug Hull, Director Kelvin Ogilvie, Acadia University, R&D done by industry, despite the General, Science Promotion and President relatively low cost of conducting Academic Affairs and through him to research in Canada, was raised. Industry Canada. The recently-released Jaap Tuiman, Memorial University of Government procurement and world strategy document. Science and Newfoundland, Vice-President product mandates were explored as Technology for the New Century (Academ ic) possible mechanisms for improving the (http://canada.gc.ca/depts/science/mai situ a tio n . n_e.html), emphasizes the importance PARTNERSHIP ACTION GROUP ON of a national innovation system with SCIENCE AND ENGINEERING (PAGSE) The positive benefits of bringing new- strong linkages between job creation, technology to the marketplace and the economic growth, quality of life and As part of the CAP'S thrust to improve need for start up funds for new advancement of knowledge - and notes interactions among science-based knowledge based companies were also the need for effective partnerships to organizations, P.S. Vincett (CAP discussed. The government is doing provide the federal government with President), B.E. Robertson (CAP Vice­ things to make venture capital available expert advice. This University Advisory President), D. McDiarmid (Director of but doesn't identify where it should be Board should be in an excellent position Professional Affairs), and F.M. Ford applied. Cameron said that the quality to respond to this interesting challenge (Executive Director) met with Michael of graduates and the research coming and opportunity. Dense of the Royal Society of Canada. out of Canadian universities is The meeting focussed on the state of recognized internationally as extremely Initial topics for discussion by the support for science within government high. The need for programs to build University Advisory Board include the (and the public in general). All parties on this research was identified. commercialization of university agreed that a broad based science research; distance education; lobbying activity was becoming critical The Science Promotion and Academic international marketing of post­ if the community was to have any Affairs Branch of Industry Canada is secondary institutions; S&T indicators; influence on science policy in the responsible for policy on university and research infrastructure. future. Dr. Dense raised the possibility research, science education and public of the Royal Society taking a leadership awareness. Doug Hull, Director General Members of the University Advisory role in this activity, which was strongly of this Department, said strategic Board (from Western Canada to Eastern supported by the CAP representatives thinking in the science policy area has Canada) include: provided a clear mandate and terms of declined in government in recent years. reference were presented to the He said that he is working to bring more Brett Finlay, University of British potential participants at the outset. people with scientific backgrounds into Columbia, Department of his Department. He also stressed the Microbiology and Immunology Several meeting have now taken place,

54 Physics in Canada March/April 1996 at which the CAP has been represented Engineers, Geologists and Geophysicists affected parties, led by the CAP by D. McDiarmid and B. Cyca (CAP of Alberta is exploring the possibility of President, P.S. Vincett, met with Councillor-at-large). Although there is a specified scope of practice under its Dr. Gerrard to discuss this matter. Also still a question as to whether this group Act. This would allow some who do present w as Paul S to tta rt w h o is on the will, in fact, form the national science engineering-related work but do not political staff of NRCan Minister lobby organization, one activity that have the required credentials for P.Eng. McLellan. We were told that Minister was recently undertaken was the status to operate under the Act. Those Manley had wanted to attend but was development of a joint response on the receiving such status would not be full not able to clear his calendar. Gerrard S&T Review report "Science and members of the Assocition and would indicated that he had been asked by Technology for the New Century, A not have final say on the conditions of Manley to find out more on the issues Federal Strategy". The CAP provided their registration. The CAP wrote to and that he would give him a full considerable input to this response, a urge the Association to first reduce the briefing. We continue to pursue copy of which follows this report. need for such status by including the meetings with Ministers McLellan and NSSC/CCPE excemption clause in their Manley. (We have been told informally This response was carefully drafted A c t. th a t there is a good chance M in ister with the purpose that it open some McLellan will agree to our request for a doors for further PAGSE input to the NSERC-RELATED ACTIVITIES m eeting.) government and its bureaucracy. The upcoming Review of Physics is an During the meeting with Dr. Gerrard, PROVINCIAL ENGINEERING ACTS extremely important CAP response to Dr. Vincett again explained the the problems caused to university community's alarm about (i) the The efforts summarized in the October- physics by the last NSERC Reallocation university research infrastructure issue, December 1995 issue of Physics in exercise. and (ii) the National Facility problem and Canada continue and have experienced the lack of an integrated policy for NFs. success in Nova Scotia. The following The CAP has submitted two major He explained how the overall situation is a resume of the more significant position papers to NSERC: one on the as a major national crisis for long-term Current activity. Rellocation process and one on the research. Strategy Implementation Report. NOVA SCOTIA: The new Nova Scotia Recent informal indications are that Dr. Gerrard indicated that they are now Engineering Act is proceeding through many of the suggestions in the CAP'S looking at a program to support the the legislature. APENS has done what Reallocation paper will be followed next research infrastructure, although (even they said they would do, so we are time; indeed, the future process may if they are successful) this could not close to our having first full province have much in common with our Review see the light of day until the next using the exemption clause. of Physics. budget. It is believed that the letters the physics community has already sent MANITOBA: The proposed revisions to A CAP-NSERC Liaison Committee has to the Prime Minister are starting to be the Manitoba Act do not contain an been established and has been of consequence; further pressure from exemption clause and the proposed operational for approximately one year. the community could play a crucial role, definition of engineering practice leaves especially if there is opposition to the much to be desired. In addition to the program from other Ministers. proposed revisions, the Manitoba NATIONAL FACILITIES (NFs) Association has also distributed to its On the NF issue, Dr. Gerrard made membership the CCPE definition of As you know, the CAP is particularly some encouraging comments on the engineering practice, including the urging action on the looming university Neutron Scattering portion of AECL. In CCPE/NSSC exemption clause, for research infrastructure issue (arising the cases of AECL-TASCC and CCFM, feedback. Several CAP officials, from the reduction and redirection of however, he was much less sanguine; including P.S. Vincett, have written the the federal transfer payments to the the group sensed real concern but also Manitoba Association urging them to Provinces) and on the threatened felt that the dollars may be too large for adopt the exemption clause. National Facilities. There are some Industry Canada to pick up the slack. Discussions with the Association significantly encouraging signs that the When asked if he would be willing (with continue with the very significant help government seems to be starting to Minister Manley) to help the CAP set up of R.C. Barber. notice the concern of the CAP. a meeting between the Minister of However, further pressure from the Finance, some of the five Canadian SASKATCHEWAN: The Government of community is still essential to build on Nobel Laureates who are helping the Saskatchewan has proposed a two this. CAP in this campaign, and P.S. Vincett, stage revision process, making some Dr. Gerrard agreed to try to help. changes now and conducting further Within the last month letters have been study before making others. The written to Ministers Manley and This group of representatives also met NSSC/CCPE exemption clause will be McLellan and to Dr. Jon Gerrard with the editorial page editor of The considered during the second phase of regarding the impact of recent decisions Ottawa Citizen. The Citizen has carried this exercise. In the meantime, a regarding funding to Canada's national a number of supportive articles and may different exemption clause will pertain, science facilities (Atomic Energy of be willing to do more. The CAP was discussions continue with B. Robertson Canada/Sudbury Neutrino Observatory, asked to provide more information on taking the lead. the Centre Canadien de Fusion this issue and to keep them informed on Magnétique, and the Saskatchewan future actions. Interestingly, the editor ALBERTA: We recently discovered that Accelerator Laboratory). On 1996 May felt that with enough grass roots the Association of Professional 2, representatives of each of the pressure this could become a major

La Physique au Canada mars à avril 1996 55 public issue, and that if it did it could rest of science when TRIUMF received radically improve the government's its renewal of funding last year. The approach to research generally. fact is that money can be found if the SCIENCE AND TECHNOLOGY FOR THE government is convinced that the NEW CENTURY: A Federal Strategy In other developments, the Bloc has arguments re good and that enough asked a series of questions in the House people care. It is up to CAP to ensure Response by the Partnership Group on on CCFM (the Tokomak de Varennes), that the arguments are stated clearly. Science and Engineering and the deputy Premier of Quebec However, it is up to the community to (M. Landry) has written to the federal make sure that enough people speak The government of Canada's long government. The Montreal Gazette has out in support that the government is awaited document on science and carried supportive articles, and the NF forced to listen. technology focuses on evaluation and issue was on Quirks and Quarks on management issues, with considerable May 4th. P.S. Vincett will, in the near The CAP will continue to do everything emphasis on performance assessment, future, be sending a full review of the in its power to defend high quality in government departments and whole long-term research issue to the research in all sectors from the effects agencies. The socio-economic benefits Globe and Mail. We hope that this will of future budget cuts. The task of of commercialization, and the job and further raise the visibility of the forming the next generation of wealth creation potential of research situ a tio n . researchers, and the scientific and and development are the centerpieces technical leadership of tomorrow's of the strategy. GENERAL OBSERVATIONS AND Canada should be a primary objective of COMMENTS our society. CAP'S task is to help create an environment where our Considering the impressive amount of While the National Facility issue is very universities and our other oustanding consultation undertaken by the serious and urgent, it represents only research institutions have the resources Government with the different one aspect of a much more serious necessary to carry out these tasks. stakeholders across Canada, the problem: that the federal government CAP will continue to work tirelessly to Partnership Action Group for Science as a whole (and there are honourable these ends. and Engineering (PAGSE) had high exceptions) does not really understand expectations for a strategy document the importance of long-term research, We thank all the CAP members (and with a timetable for deliverables. It and is pursuing policies which (perhaps others) who have written in support of anticipated a form of "white paper” unintentionally) are likely to seriously the CAP'S April letter to the Prime with an action plan for implementation damage it. The infrastructure issue is Minister. We are now seeing that of new tools and new directions. We perhaps the most obvious example. We sustained and reasoned pressure can be also expected the document to specify, must draw a 'line in the sand' now and heard. Those who have not written to in a fiscally defined sense, the value say 'enough is enough’. If we do not Dr. Gerrard, Minister Manley, and the and significance of the full spectrum of do this, and if we do not defend other Ministers involved should give research (i.e., the continuum from basic physics with one clear voice, we have serious consideration to doing so now to applied) and development for been told many times by politicians and (the fax numbers are given below). enhancing the quality of life of our civil servants that things will only get Equally important - as stressed by citizens. While the document does not worse. The whole community must almost every government representative attain these goals in a substantive way, come to the defence of whichever part we have met - call or write your local PAGSE does enthusiastically endorse of us is under attack at any given MP and MPP/MLA/MNA. Emphasize some of the points made in the report. moment. If we wait until our own whichever issue is of most concern to These include the: institution or our own type of research you, or discuss them both, but let's is threatened, then the government will keep up the pressure! (a) Recognition of the need for simply play the game of divide and constructing a broad base of scientific conquer. One senior civil servant said The Rt Hon. Jean Chretien: (613) enquiry in all major fields of endeavour. to the CAP some time ago that 'we can 9 4 1 -6 9 0 0 pick scientists off one at a time'. To (b) Statement that "research, both prevent this, we must speak as one Dr. Peter Adams, M.P. (Chair, Liberal basic and applied, provide a continuous, community whenever a key part of the Caucus Committee on Higher renewable source of skills, ideas, overall fabric of research is threatened. Education): (613) 996-9800 technologies, and policies ..."

In defending several specific parts of Hon. John Manley (Minister of Industry): (c) Support of funding and performing the community, we must always (613) 992-0302 or 995-1534 scientific research within government address broader issues and appeal to departments and agencies; research in broader principles which all physicists Hon. Jon Gerrard (Secretary of State post-secondary institutions; corporate can support. We must be very careful for Science, R&D): (613) 990-4056 or research and development; centers of not to suggest that some other part of 9 4 7 -4 2 5 0 excellence. research be sacrificed to support another. There is no evidence that the Hon. Anne McLellan (Minister of Natural (d) View that quality science is central situation is really a zero sum game. Resources, which has responsibility for to sound policy development. After all, the funds lost to science as a AECL and CCFM): (613) 996-4516 result of the actions on the national (e) Formation of a new Advisory facilities have not been transferred to Hon. Paul Martin: (613) 992-4291 or Council on Science and Technology/ NSERC! Nor, as far as we are aware, 9 9 5 -5 1 7 6 Innovation which would provide direct was there any significant impact on the input to cabinet on research and

56 Physics in Canada March/April 1996 development and other priority issues. researchers who need to make use of international S & T collaboration for the PAGSE anticipates that the Council will the facilities cannot afford to pay the benefit of Canadian firms, little is said address some of the concerns of the technical support costs required to get concerning the collaboration . of science community. the work done! university and government researchers on an international basis. The cost (f) Requirement that government Clearly, in accord w ith II, should benefit analysis to our researchers, the departments and agencies establish government decide that there is no enhanced opportunities to perform mechanisms to secure external prospect for a marked increase in the cutting edge research, and the goodwill assessment of the extent of funding of research in Canada, in the such collaboration brings to Canada, are achievement of milestones, and advice next 3-4 years, priority decisions must substantial indeed. on future programs and priorities. be made in allocating resources for research across government There is no central fund to encourage (g) Creation of partnerships and departments, and amongst the three and foster Canadian participation in networks between combinations of principal granting councils. The planned international S & T. Given the fact that individuals from the private sector, Advisory Council (subject to its detailed NSERC has eliminated international government, and universities. terms of reference) or other bodies (i.e. programs, that other government cross government departments, cross agencies and departments (e.g. Foreign Some of the concerns which PAGSE granting councils) could make Affairs) have also significantly reduced has include: recommendations in this regard. The their budgets in these categories, some successful British example of a acknowledgement of the vitality of I. Some of the positive points, Technical Foresight Committee may be international collaboration was in order, especially a-d above, while laudatory, instructive in this regard. as one mechanism for Canadian are "motherhood statements” and are researchers to compete on a global not "front and center” in the document. IV. While PAGSE is cognizant of the basis. These statements will not have any need by government to emphasize the lasting value unless there is a specific commercialization of science and VIII. The overriding concern of the allocation of resources, concurrent with technology, the group was struck by document is research performance and a draft plan for policy implementation, the inattention (except statements a accountability in government agenpies developed in concert with the S & T and b above) to specifics on basic and departments, with only a co m m u n ity. research as the foundation and "broad-brush" treatment of university galvanizer for technology development research and, for that matter, research II. PAGSE is w e ll aw are of th e existing and commercialization of new and development in the private sector. and anticipated budgetary constraints. processes, as well as for the The latter two are central to any Consequently, although all major fields manufacture of new products (and successful S & T strategy leading to job of endeavour merit some support on the more economical routes to existing creation and economic success. basis of excellence, allocation priorities commercial items). must be made (by appropriate bodies IX. There is a major concern about which serve the different communities V. A major impediment to the mechanisms of governance and universities, government, corporate commercialization of Canadian research provision of S & T advice. The sector) to a much greater extent and at and development is the reluctance of effectiveness of a new Advisory a more detailed level, than those financial institutions to provide Council on S &T/lnnovation will heavily described in the strategy document. financing for late-stage development depend on the quality of its and initial production of new products membership. It would be inappropriate III. Canada lags far behind our major of small and medium sized enterprises. to have such a Council selected entirely competitors in terms of percent of GDP While partially addressed by the S & T from the private sector (as has been invested in R & D. As pointed out in Strategy, this needs to be recognized as suggested). In Canada, private sector the Red Book, this is largely the result a continuing problem requiring research and development is weak and of underfunding for industrial science additional responses. it would be unfortunate if strong and technology by the private sector. representation from practicing scientists Until research and development is given VI. PAGSE agrees that the Information or engineers in the academic and a higher priority by government, Canada Highway is a valuable tool for government communities were not will continue to lose in the race for facilitating communication and involved. Also an international technological competitiveness. networking amongst researchers and presence would be very useful. others i.e. it contributes to the research W hile th e paper is com m endable in infrastructure. The strategy document In conclusion there are, as in any promoting partnership agreements, gives readers the impression that the IH document of this type, positive and collaborative programs, and an is more than a tool. Redundancies negative components. Some elements open-door policy for laboratories, resulting from the expansion of the IH are sensible, realistic, and merit nowhere does it address the issue of will in our view be substantially, if not the underfunding of research in Canada. follow-up. This document is one of completely, offset by the need to create A partnership between two "process" and PAGSE urges the new positions for information analysis underfunded groups (eg., universities development and implementation of an and dissemination. and government research laboratories) "action plan." We are ready to work is not necessarily a prescription for with government on this and other VII. While the recommendation is made success. Furthermore, there is little issues of relevance to science and that federal departments and agencies point in government laboratories having technology. develop explicit plans to promote an open-door policy when the university

La Physique au Canada mars à avril 1996 57 N E W S / NOUVELLES MANLEY ANNOUNCES TWO NSERC 1996 NATIONAL COMPETITION average of 9.6%). Two-thirds of these APPOINTMENTS TO NSERC RESULTS ANNOUNCED graduates are active in R&D. A On January 18, 1996, Industry Minister (Gov t of Canada Preaa Releaae dated Apr. 4/96) significant proportion of the others are John Manley announced the appointment involved full time in such professional of Angus Bruneau and Julie Payette to the Dr. Tom Brzustowski, President of the activities as teaching, product Natural Sciences and Engineering Research Natural Sciences and Engineering Research development, consulting, and Council (NSERC). Council of Canada (NSERC) in announcing management. the results of the Council's 1996 national Angus Andrew Bruneau is the Chairman, competition for research grants and More information about the impact of President and CEO of Fortis Inc. The scholarships (4,125 new awards totalling NSERC-assisted research and training can holder of a doctorate in Physical Metallurgy $ 122 million) stated that "Our researchers be found on their Web Site in the from the University of London, his and university training in research rank publication Research Means Business. experience in business and academia is among the best in the world, in terms of vast. It includes 10 years with Memorial both quality and productivity. We have in PUBLIC HEARINGS FOR NUCLEAR FUEL University of Newfoundland and 7 years at this country developed excellent systems WASTE MANAGEMENT AND DISPOSAL the University of Waterloo, and acting as for assessing the quality of our research CONCEPT ANNOUNCED director of a wide variety of companies activity, and we know that in all the Public hearings to review Atomic Energy of over the last thirty years. Dr. Bruneau has important areas of research Canadian Canada Limited's proposed nuclear fuel also served on committees and the boards universities are achieving a great deal with waste management and disposal concept of several national and international resources that are modest by international were held in Toronto, Pickering, Thunder research and economic development standards." Bay, Sudbury and Chalk River from March organizations, including the National through May, 1996. On February 1, Research Council, NSERC, and the OECD. Dr. Brzustowski said the Council was 1996, a detailed schedule for the hearings resuming the annual announcement of its were released by the federal environmental Julie Payette was selected as a member of awards because of growing public interest assessment panel reviewing the waste the Canadian Astronaut Program in 1992. in science and technology. "Today, we are management and disposal concept. Building on a Bachelor's degree in all very conscious of the economic Engineering from McGill and a Master of implications of activities on which we Phase I hearings took place in Toronto and Applied Science from the University of spend public funds. Basic research is an Pickering, March 11-15 and 25-29, 1996 Toronto, she is currently working towards extremely important activity. It builds the and Thunder Bay, Sudbury and Chalk River a doctorate in Electrical Engineering at stock of knowledge in our society. But from April 29 to May 2, 1996. This phase McGill. Ms Payette's design and research promoting awareness of it and using the focused on the presentation and round­ experience includes areas such as human results productively are equally necessary table discussion of broad societal issues computer interfaces, speech processing in activities." related to the long-term management of adverse environments, and the application nuclear fuel waste. Discussion papers are of voice technology to space. She has A full list of the results of the 1996 grants available on request from the panel worked with IBM Canada and the Speech competition can be obtained from NSERC's secretariat. Research Group at Bell-Northern Research. Web site on the Internet at http://www. Ms Payette is one of two nominated nserc.ca/newsl .htm. Phase II hearings, to take place in Toronto Canadian specialists on the NATO from June 10-14 and 17-21, 1996 will International Research Study Group on The Impact of the Research Investment consist of technical sessions focusing on speech processing. the long-term safety of the Atomic Energy • 40% of the annual total Canadian of Canada Limited concept of geologic REQUEST FOR PROPOSALS (RFP) industrial investment in university disposal from scientific and engineering Technology Development Program in research is directly linked to NSERC viewpoints. More information concerning Intelligent Systems and Robotics funding for basic and project research. these will be available at a later date. On January 26, 1996, PRECARN More than 1,000 companies have Associates Inc. issued a Request for directly contributed over $300 million to Phase III hearings will consist of Proposal (RFP) for their next wave of date to university projects, the majority community visits in New Brunswick, funded research programs. PRECARN in of which build on the outcomes of Q u e b e c, Ontario, Manitoba and association with CATA, seeks the earlier NSERC investment in basic Saskatchewan where participants will have participation of industry members in its university research. an opportunity to provide their final industry-led, collaborative research opinions and views on the safety and program. PRECARN will contribute up to • Companies along the section of road in acceptability of the concept for disposal of 40% of eligible project costs (in intelligent Kanata that runs from Digital to nuclear fuel waste including any other systems and robotics) up to $1 million, Newbridge Networks Corp. produce issues relevant to the panel's mandate. inclusive of early stage commercialization. total annual sales in excess of $3 billion The schedule will be announced later. Total investments will exceed $65 million - of which more than 80% is from between 1 996 and 2000. exports. These firms are highly For more information, please contact dependent on the quality of young Ghislaine Kerry by telephone at This RFP is open to all PRECARN Members recently trained engineers and (819)953-0179 (collect), by fax at and to new partners which commit to scientists. The companies employ (819)994-1469 or by internet at become PRECARN Members, if their 9,000 people directly, with the [email protected]. projects are approved. Research areas are companies that service them employing classified in these categories: robotics, a further 27,000. Canada’s largest DOCUMENT ORDERING ON THE WORLD machine sensing, human machine interface R&D performer, Nortel, attributes its WIDE WEB and intelligent computation. significant global success and future The World Wide Web offers CISTI clients prospects to its high investment in R&D an additional electronic document ordering CATA is publicizing RFP inform ation on its and to the quantity and quality of talent method. Because orders submitted by this Technogate World Wide Web databases recruited from Canadian universities. method flow directly into CISTI’s (http://www.technogate.com ). Interested automated document delivery parties should click on the Technogate • Surveys of the career status of previous system,processing costs are reduced. "Partners and Allies" icon and search under holders of NSERC’s national CISTI passes these cost savings on to "R&D” or "PRECARN" or click on "Hot scholarships consistently indicate a very clients in the form of lower service fees. Links" and then "Research and low rate of unemployment (less than Development." 3%, compared with the current national

58 Physics in Canada March/April 1996 Any registered CISTI client with access to arising from the university promotion and engineering at the University of Waterloo the World Wide Web can order documents tenure process. for 25 years, he also served as vice­ this way. You need a CISTI account president, academic, and provost of the number beginning with the prefix FGH, WK Council took another significant step university. After leaving the academic or DD, plus a password. All clients with towards implementing the world, he was appointed deputy minister the FGH and WK accounts already have a recommendations of the Strategy of colleges and universities in Ontario, then password; most clients with a DD account Implementation Task Force by approving deputy minister of the Premier's Council of do not. To obtain a password for a DD the regrouping of activities in the Targeted Ontario, a body charged with developing account, or to register as a new client, Programs area. The new Research strategic policy advice to the government. please contact CISTI's Client Registration Partnerships Program has three main a t: Phone: (613) 998-8544 or components: Strategic Projects, University- But he says it w as his stint in the 1-800-668-1222 Fax: (613) 954-2217 Industry Projects and Research Networks. university classroom that now serves him E-mail: [email protected] best. "It's amazing how 25 years of To register electronically, fill out the Client Council and staff are continuing to work classroom teaching, particularly teaching in Registration Form found on the Web at on suggestions for implementing the Task the lower years of undergraduate www. cisti. nrc. ca/ cisti/register. htm/ Force's recommendations regarding education, can alert you to communicating NSERC’s Scholarships programs, and in simple terms. It's nice to teach a FREE ACCESS TO CISTI'S ONLINE Accountability and Communications. graduate course in your own jargon. But CATALOGUE when you're facing intelligent questions in Access to the online catalogue of the Information on the implementation of the simple terms, from people who haven't Canada Insitute for Scientific and Task Force’s recommendations will be learned the jargon yet, then you have to Technical Information (CISTI) is now available through Contact and NSERC's scram ble." available free using the Internet. The Web Site (http://www.nserc.ca). catalogue is a listing of titles for all major Eventually he hopes the result of his publications (serials, books, conference TELLING THE RESEARCH STORY (from crusade to focus public attention on proceedings, reports) in the fields of University Affairs, March 1996) science and engineering will be increased science, technology, engineering and Tom Brzustowski is not afraid of straight public understanding - and financial medicine worldwide. It is updated every talk. And he thinks it's crucial that support - for university research. "I would week. Those who do not use the Internet Canadian university researchers get just as like to see widespread recognition in this to access the online catalogue will pay a fired up about communications as he is. country, and great conviction, that it is telecommunications charge. essential to invest in research, science and "Communications is a short term and a technology and graduate training of CISTI’s online catalogue can also be used long term priority for me,” says researchers, just for the good of the to order copies of the full texts of these Dr. Brzustowski, who took over the helm country," he declares. ”1 really would like publications, but you must be registered at the Natural Sciences and Engineering to see research considered as something with CISTI to place an order. Most orders Research Council last September after a essential to Canada, and not as just a sop are filled within 2-3 days, or there is a career as a university researcher, to the egos of academics, not as just 4-hour urgent service available. administrator and senior provincial civil another kind of social consumption, but servant. "At every opportunity that arises, something that is the mechanism by which Both registered and non-registered clients we will explain what the research we build the future." can also access the catalogue on the community does in a way which is World Wide Web at www.cisti.nrc.ca/ interesting and memorable, giving The communications challenge is cisti/. To ensure a successful connection examples, giving illustrations of outcomes, particulary important these days, with to the CISTI Online Catalogue, Web users and all in plain language, not jargon.” university researchers squeezed by multiple must configure their Telnet software to pressures. Science and engineering work with their browser (eg. Netscape, In times of shrinking resources, university disciplines are breaking new ground; ideas Mosaic, etc.) professors can no longer afford to stay and new directions for investigation are cloistered in their research labs or isolated emerging daily. At the same time, granting NSERC CANCELS CPG PROGRAM in their classrooms. Instead, they have to council budgets are decreasing, and (Contact Vol.20(3), Written 1995) be prepared continually to explain what operating grants from the provinces to At its meeting in October, NSERC they do, justify it, and then convince a universities, which help pay the costs of approved the phase-out of the jaded and tax-weary public of the university research infrastructure such as Collaborative Project Grants (CPG) importance of funding it. libraries or laboratories, are also on the program, as recommended by the Strategy decline. In order to cope, many Implementation Task Force. Although "Take nothing for granted," Dr. researchers are turning to NSERC with there will be no more competitions, Brzustowski tells researchers. "Just requests to fill the gap, to provide funding commitments made in the 1994 and 1995 because what you are doing is very, very out of operating grants to equip competitions will be respected. Given the good, it's elegant and it's important in your laboratories or pay for other infrastructure- financial environment projected for the discipline, and just because it's already related costs. coming years, it was clear that resources being funded, doesn't mean that anybody would not be sufficient to allow the CPG is interested in it outside of your "It seems that, increasingly, grantees are program to achieve its objectives, and that discipline." facing universities that are asking to be Council’s efforts would be better spent in paid for the (research infrastructure), encouraging collaboration across all The days when researchers could view any because universities can no longer afford programs. media questions or politicians' inquiries to provide these things for free. So we’re about their research as an unwelcome getting a trickle, turning into a flow, and Reiterating its commitment to collaborative intrusion or interference are gone, Dr. probably a flood of requests" to spend research, Council mandated staff to work Brzustowski adds. "The attitude that NSERC money on research infrastructure. closely with the research community to somehow the quality of your work is But such requests have a direct impact on ensure that practices both in the peer sufficient to justify whatever amount of the bottom line. "Every time we do that, review process and in the universities support you get - that was a very nice there is less money available for other promote the emergence of excellent attitude to have. But resources can't keep things." collaborative proposals. As a first step, up with that." the distinction between NSERC individual Dr. Brzustowski says he is becoming and team Research Grants will be Dr. Brzustowski's career path has left him increasingly concerned that NSERC funding removed. Staff was also encouraged to equipped to understand the point of view is being seen on campuses as the sole develop closer ties with universities to try of both university professors and political source of funding for science and to break down barriers to collaboration leaders. A professor of mechanical engineering research. And he's worried

La Physique au Canada mars à avril 1996 59 that, sooner or later, university In building up trust between NSERC and His return follows more than 11 years at adm inistrators may refuse to sign NSERC the academic community, Dr. Brzustowski the University of Rochester where he grant applications, including those for believes it is im portant to allay researchers' conducted pioneering research in solid- major equipment, on behalf of their concerns that NSERC may be turning its state laser technology and spectroscopy. researchers, because the institutions back on basic research. "I think one of the Although he was born in Canada and simply can't afford to supply the things that the community will need to be received his BSc (honours) degree from the infrastructure needed. informed about, and to become less University of Manitoba, he says the United anxious about, is the notion that somehow States provided greater research But although NSERC officials are worried, there is room within NSERC for both kinds opportunities, especially for new faculty. it's difficult to track how much impact any of research, both the basic research and crumbling in university infrastructure is project research." "Canada has not been willing to having. Dr. Brzustowski fears the effects sufficiently invest in their young scientists may show up first in decreased One problem may be that researchers fear and consequently has lost some applications for NSERC grants. "We won't that NSERC will take a "one size fits all" outstanding talent," says Miller. "I was begin to see this until the grant selection approach to science, a fear Dr. really impressed by the level of support committees begin to point to it, maybe not Brzustowski says is groundless. Too and enthousiasm generated by Lumonics, in this year’s competition, maybe only in often, he notes, applied or project-based NSERC and the U niversity of Toronto to next year's. But if, in key areas in the researchers fear that the values of basic reverse the trend. This was an opportunity basic disciplines, holes develop, not just in research - counting the number of to make a difference to Canadian science the capabilities of individual institutions, publications, for example - will be applied I could not refuse." In the U.S., Miller was but across the country, then no amount of to them, while basic researchers worry a recipient of an NSF Presidential Young networking will be able to patch that up. they will be asked to demonstrate the Investigator Award, Dreyfus Teacher- And as a national agency we're going to immediate economic relevance of their Scholar Fellowship, Alfred P. Sloan become very concerned about it." w ork. Fellowship and his research was further supported by the National Science Dr. Brzustowski says he is interested in In fact, says Dr. Brzustowski, NSERC will Foundation, National Institute of Health, proposals - such as one made recently by apply "appropriate measures" to each and the Department of Energy. the Association of Universities and activity. In the meantime, he calls for a Colleges of Canada - that would see the kind of truce between faculty involved in federal government pay directly for the basic research and those working on INTERNATIONAL NEW S/ infrastructure costs of the research it applied projects. "Let's not create sponsors, rather than relying on transfer anxieties where they don't have to be NOUVELLES INTERNATIONALES payments to the provinces. created." he urges researchers. "Let's not A LIGHT NIGHT READING? have any sneering across the interface ... (IOP Press Release, undated) But such a proposal, too, raises a you know, well, what you do is irrelevant, Researchers worldwide can now gain communications challenge, and what you do is not intellectual online access to developments at the Dr. Brzustowski notes. How will enough." frontiers of physics from the comfort of universities convince the public that such their own desks, 24 hours a day, seven a move does not represent increased Dr. Brzustowski says he is optimistic such days a week. budgets for the granting councils, but differences between researchers can be rather simply shifts the method of worked out - just as he is optimistic that In a major international initiative, the UK- allocating the funding? "The issue isn’t decision-makers will eventually heed his based Institute of Physics Publishing is doubling the councils' budgets, it's finding message about the importance of making all its research journals available on the other half of research costs. That has university research in science and the Internet to scientists whose to be communicated with precision," Dr. engineering. institutions subscribe to the well Brzustowski says, "Otherwise the public established paper versions of the journals. would be right to reject the move." "Let's put it this way," he explains. "I've Not only will articles be available had nobody come around and tell me electronically up to three weeks before Although communications with the general there's good news for NSERC in the next they appear in print, researchers will also public is evidently his priority, (federal) budget. But on the other hand, be able to access them via the World Wide Dr. Brzustowski is clear he also intends to I've met an increasing number of elected Web at no extra cost. build bridges to the university research officials here in Ottawa who acknowledge community. In fact, he makes it a point the importance of university research The journals produced by Institute of not to distinguish between the granting funding. Now at some stage of the game, Physics Publishing cover the full gamut of council and the com m unity. "I see NSERC something's got to give." physics research, with topics as diverse as as almost an organ of the community," he nanotechnology, plasma physics, says. "I don't see it as having goals physiological measurement, nonlinearity distinct from the research community. It UNIVERSITY NEWS / and the public understanding of science. really is a voice of the community." ÉCHOS DES UNIVERSITÉS The Institute of Physics Publishing journals But, he admits, in the past there may well COOPERATIVE EFFORTS FUND now available on the Web are: Journal o f have been some communication RESEARCH Physics A: Mathematical and General; breakdowns between the granting council (University of Toronto Medal Release January 25/96) Journal of Physics B: Atomic, Molecular and a number of university researchers. Cooperative efforts between the National and Optical Physics; Journal of Physics D: And, after several months on the job and Sciences and Engineering Research Council Applied Physics; Journal of Physics G: visits to several university campuses, he is (NSERC), international technology Nuclear, and Particle Physics; Journal of surprised how little some professors know company Lumonics, Inc. and the University Physics Condensed Matter; Measurement about how NSERC is funded and how it of Toronto are helping ensure that one of Science and Technology; Classical and conducts its business. Some professors, Canada’s most important "natural" Quantum Gravity; European Journal of for example, continue to believe that resources remains in Canada. Physics; Nonlinearity; Physics in Medicine NSERC council members give up their and Biology; Plasma Physics and academic careers and move to Ottawa Dwayne Miller, a top researcher in laser Controlled Fusion; Pure and Applied once they are appointed. Surprisingly, technology, has returned to his native Optics; Semiconductor Science and some faculty are also unaware of the Canada after several years in the United Technology; and Superconductor Science volunteer commitment needed from States to join the University of Toronto as and Tedhnoiogy. academics across Canada to maintain the the holder of the NSERC-Lumonics Chair in granting council's peer review process. Quantum Optics. Further information and demonstration material is available at http://www.iop.org

60 Physics in Canada March/April 1996 CANADIAN PHYSICISTS / PHYSICIENS ET PHYSICIENNES CANAD!EN(NE)S

Excellence in Teaching Awards don't be shy about pointing it out. starting to address the question of what (Extract from Simon Fraser News, Fab. 8/96) Students should know that you really want this means for the electrical and magnetic to be there. properties of these materials." Howard Trottier, physics, was selected as one of the three winners of SFU's McMaster University Researcher Captures It was only by chance that Dr. Kallin, now excellence in teaching awards this year. In National Science and Engineering Prize recognized as one of the top condensed an interview with Simon Fraser News matter theorists in the world, got into reporters. Dr. Trottier had the following to On 1996January 1 7 Dr. Tom Brzustowski, physics. In high school she dropped say about his teaching ... President of the Natural Sciences and physics after Grade 10. It was a Engineering Research Council of Canada community college course in "physics for Are there any special techniques you use (NSERC) announced the winners of some poets" that piqued her interest in the to motivate your students? of the country's most prestigious awards. subject and led her to the honours physics Demonstrations. They're a big part of Recipients were selected from nominations program at the University of British teaching physics, at least in our from universities across Canada. Columbia. department. Actually measuring the acceleration of a ball as it's dropping will Four outstanding professors will receive (For more information on Dr. Kallin, see the always be more convincing than working it the 1996 E.W.R. Steacie Memorial family profile on Dr. Kallin and out through equations. Things like that Fellowships. "These individuals are Dr. Berlinsky which appears later in this resonate with students. Often when I’m creating international recognition for issue.) wheeling equipment down a hallway I can Canada in some of the most exciting fields see that students are genuinely excited of science and engineering,” said NEWS FROM CORPORATE, that there's going to be a demonstration in Dr. Brzustowski. "They underline the MEMBERS my lecture that day. extraordinary high calibre of research and training in Canadian universities." In your opinion, what are the top three L'INO FAIT UN DON D'ÉQUIPEMENT AU CÉGEP DE LA POCATIÈRE qualities that make a good teacher? Dr. Catherine Kallin is an outstanding Le président-directeur général de l'Institut Teachers need to project themselves - to scientist in the Department of Physics, national d'optique (INO), monsieur make eye contact with students in the McMaster University. She has Jean-Guy Paquet, a été très heureux back row. I like to get right in the middle demonstrated exceptional leadership and d'annoncer le 20 février 1996 à of a class and jump up and down. And I accomplishment in theoretical solid state La Pocatière, le don par ΓΙΝΟ au Cégep de make no apology for putting entertainment physics, particularly in the theory of high la Pocatière, du système d’écriture FAB value in my lectures. Second, teachers temperature superconductors. have to be accessible. I have open office pour des fins d'enseignement et de formation des étudiants en technologie hours. If I'm on campus, students can ask Other recipients include Dr. Ming Li, physique. me questions anytime. And like other mathematician at the University of faculty in the physics department, I drop Waterloo, Dr. Jed Harrison of the by our open labs to make myself available Ce don a été possible suite au Department of Chemistry, University of remplacement du système d'écriture FAB to students in an informal way as often as Alberta, and Dr. Demetri Terzopoulos, par un équipement plus performant possible. Finally, everyone appreciates a Department of Computer Science, good jo ke in class: 'Physics humour', as rencontrant les nouveaux besoins des University of Toronto. activités de ΓΙΝΟ. «Nous sommes my wife calls it, because often the joke isn't funny outside the lecture. For convaincus que le système offert The NSERC awards provide the recipients permettra au Cégep de réaliser plusieurs example, I found a clip from S tar Trek in with an opportunity to expand their which Captain Kirk and Spock are talking nouvelles activités pertinentes pour la research programs and obtain additional formation des étudiants», a affirmé about anti matter. It's become part of my research assistance. The prizes will be monsieur Paquet. teaching arsenal. I play the video in class officially presented in June along with the after teaching the subject. Students can Canada Gold Medal for Science and L'INO compte présentement à son emploi spot what's wrong immediately as the Engineering. vingt-cinq technologues, dont vingt sont characters worry that if Lazarus meets his des diplômés en technologie physique du anti matter twin, it will be the end of life Short Article on Dr. Kallin Cégep de La Pocatière. «Nous sommes as we know it. The overacting and parmi ceux qui connaissons, et overdrawn music add to the hilarity of the McMaster University physics professor reconnaissons, l'excellence des diplômés conversation, so it works very well in Catherine Kallin and her collaborators have en technologie physique du Cégep de La class. been studying microwave measurements Pocatière, et nous sommes heureux de on high-temperature superconductors, and pouvoir offrir un appareil qui contribuera de What challenges do you expect to confront using the data to determine the electrical manière tangible à la formation des futurs as a teacher in the immediate future? and magnetic properties of these technologues», a ajouté monsieur Paquet. It may be inevitable that class size will superconductors and to understand why D’ailleurs ΓΙΝΟ prévoit procéder d'ici le increase because of cutbacks and demand. the materials are superconductors at all. mois de mai prochain au recrutement d'au I think big classes are a serious problem. moins trois nouveaux technologues en They make students feel totally "Our traditional understanding of physique parmi les finissants de cette anonymous. In my experience, smaller superconductors, which werediscovered in année. classes (even in the 100-200 student 1911, strongly suggests that superconduc­ range) provide for more teacher-student tivity shouldn't exist above 30 degrees Rappelons que l'Institut national d'optique, contact. For the physics department, low Absolute (-243 degrees Celsius)," explains qui emploie à son siège social de Sainte- enrolment, particularly in the upper levels, Dr. Kallin. But high-temperature Foy plus de cent trente personnes dont has to be addressed, if we expect to superconductivity (above 30 degrees quatre-vingt scientifiques, est une attract more students, they have to be Absolute) was discovered in 1986, and in corporation privée sans but lucratif qui a able to get jobs. This is a problem which subsequent years the temperature vu le jour en 1985. L'INO est l'un des my department is taking seriously. escalated to the present record of 160 chefs de file international de la recherche degrees Absolute (-113 degrees Celsius). et du développement en optique, et vise à What advice would you give to someone "There's a large body of evidence that favoriser l’essor économique du pays en just starting their career as a university points to electron-electron interactions as assistant les entreprises dans leurs efforts teacher? Be enthusiastic. Search for th e cause of h ig h-1 em pe ra t u re pour améliorer leur compétitivité. something great in the smallest detail and superconductivity. But we’re just now

La Physique au Canada mars à avril 1996 61 THE PHYSICS OF DILUTE 2D ELECTRON AND HOLE SYSTEMS IN SI-BASED HETEROSTRUCTURES

by Marie D’lorio Institute for Microstructural Sciences, National Research Council of Canada, Ottawa, Ontario K1A OR6

INTRODUCTION where Vc ~ e?M a and ε is the dielectric Experimentally, the problem lies in the constant. fact that the carrier density required for Starting with the discovery of the observing the quantum solid phase is Quantum Hall Effect at the beginning of When Γ is large, the formation of a solid very low in III-V semiconductors which th e 1980’s, the field of low is favored over that of the liquid. typically have low effective masses and dimensionality electron systems has Electrons on a helium film provided the large dielectric constants: r„~ 2-4 < < r,w . known an incredible expansion. In first observation of a classical Wigner Electrons on helium have the opposite semiconductors, the confinement of solid at zero magnetic field and the problem where the density is kept low to charge carriers in two or fewer melting temperature was found to occur avoid a destructive instability of the dimensions provides added richness from at Tw = Vc / ( T J t j w ith r m = 1 2 7 ± 3 helium surface: r, > 103 > > r,w. The both the fundamental and the applied I4-8I. search should thus focus on material physics viewpoint. Solid state vocabulary systems with a large effective mass, a has expanded to include the integer and (b) The quantum regime occurs at low low dielectric constant, and in situ the fractional Quantum Hall Effects temperatures when T < < TF and the density tunability. We should also search (IQHE, FQHE), skyrmions, composite parameter of interest is the ratio of the for other material features which favor fermions, high electron mobility Wigner-Seitz radius, a to the Bohr radius the onset of crystallization. This is the transistors (HEMT), modulation doped aB: approach that we will be discussing. field effect transistors (MODFETs), resonant tunneling diodes (RTD) etc. In r, = a /aB = Vc/(kBTf) What are the signatures for the formation the quantum limit of low temperature and of the Wigner solid phase? Just like its finite magnetic field where the mobility μ and liquid counterpart, the electron solid is a and the magnetic field B are such that collective phase; this is in contrast to the μΒ>>1, charge carriers confined at the a B = tfe /lefm *) gas phase where the picture of a non­ interface between two semiconductors or interacting gas usually suffices. The between a semiconductor and an The electrons order into a Wigner crystal solid, however, should have rigidity insulator behave as a gas of non­ when r3 is large and the Coulomb which will distinguish it from a collective interacting particles (electron gas), while, correlations dominate; as the carrier liquid state. From magneto-transport in the extreme quantum limit where the density increases and r, decreases the experiments, one would expect some cyclotron energy h(oc is much larger than quantum fluctuations grow until the long extremely large resistance associated the thermal energy kBT, the fluctuations range order disappears and the solid with the localization of the charge promote the formation of a liquid state. It melts. This occurs at a critical value r “ carriers onto lattice sites and their was natural then to look for the third = 3 7 ± 5 or critical density tf = π /(r,n inability to participate in the transport. state of matter, the solid in two dimen­ a j 2 as determined by a finite size, zero But that in itself is not sufficient since sions. This idea was not new, as it had temperature calculation [9], single-particle localization will also lead to been addressed by Eugene Wigner in insulating behavior. The current-voltage 1934 [1] for three dimensional metallic (c) It is also possible to induce the characteristics could however provide systems. Wigner predicted that, at zero crystallization of electrons by applying a unambiguous evidence for a solid phase. magnetic field, the density of the carriers magnetic field perpendicular to the layer The presence of an electric field could be reduced such that the Coulomb and localizing the electrons within a threshold conduction is indicative of exchange would be larger than the magnetic length tc = /hc/eB)h, smaller rigidity: below threshold, the electrons thermal disordering energy, thus favoring than the Wigner-Seitz radius a . The are pinned which is not possible in a the crystallization of electrons onto quantum fluctuations are quenched and liquid phase, while, above threshold, a lattice sites. This was later applied to the there is little overlap between the collective sliding motion of the depinned two-dimensional case where the electron wavefunctions. The ratio of the electron solid occurs. The resistance conditions for observing the electron zero point energy to the magnetic or below threshold is usually activated due solid are less stringent than in three cyclotron energy hcocwhere a>c = eB/m*c to electrons excited across a "single­ dimensions 12,31- is provided by the filling factor v = electron" disorder induced gap. The 2dc/a )'> . The magnetically induced conduction here can involve the transport BACKGROUND Wigner solid is expected to form at finite of electrons along the grain boundaries of There are two regimes for the formation temperature at a filling factor smaller the Wigner solid or the transport of of a solid phase depending on whether than some critical value vc which has dislocation pairs. A lew value of the competing fluctuations are thermal or been estimated to be between 1/3 and threshold field implies a long correlation quantum in nature. 1/11. The phase diagram is illustrated in length with respect to the Wigner-Seitz Fig. 1. radius. Another signature of the Wigner (a) In the classical regime, the zero point solid is the increase of broadband noise energy is much smaller than the thermal n. as the threshold field is approached; this energy kBT : corresponds to the onset of sliding and the noise generated by the electron kBTF = t f /

62 Physics in Canada March/April 1996 sufficient surface roughness to pin the In order to observe a quantum Wigner 5x1010 to 1012 cm2. The longitudinal Wigner crystal formed by the electrons. crystal, in the zero field limit predicted by resistance is measured using a four probe Associated with this pinning are non­ Wigner, one must look for a material technique with a differential electrometer linear current-voltage V-V) characteristics system with large effective mass to and DC currents as low as 0.1 pA. The which were first observed by Kajita 111], minimize the zero point oscillation energy Oxford Instrument low temperature Above a threshold electric field, the and a small dielectric constant to system consists of a top loading 400 ^W depinned crystal slides like a sliding maximize the Coulomb correlation dilution refrigerator (25 mK < T < 4.2 charge density wave. Experiments on a energy. Moreover, rt is im portant to be K) and a superconducting magnet (H - two-dimensional sheet of electrons able to vary the density in a reliable and 0-15 Tesla @ 4.2 K). One of the main injected on a helium film (thickness 200­ reproducible fashion. Almost optimal differences between Si-MOSFETs and 400 A), supported by a glass substrate, conditions can be created in several Si- GaAs/AIGaAs modulation doped have shown that the transport properties based materials as shown in Table 1. heterojunctions is the location of the of the pinned electron lattice are very dopants similar to that of one-dimensional sliding Table 1. Comparison of parameters of interest for Wigner crystallisation which charge density waves: characteristic non­ control the linear l-V curves, melting temperature, scattering and broadband noise generation 1121. P a ra m eter Si / S iG e Si / S i0 2 events and hence limit Electron effective mass : The initial effort in identifying a Wigner 0.44 0.19 the mobility. crystal phase in semiconductors was m* I n S i - carried out in GaAs/AIGaAs Dielectric constant : 12 7.7 MOSFETs heterostructures [13-151. There, it was < K > the dopants not possible to decrease the density are located sufficiently to observe the Wigner crystal Bohr radius : in the Si at zero magnetic field. Thus the _ _ ( 4 ^ „ X f t 2x ) close to the experimental efforts were focused on the 14 A 20 A inversion B r n e 2 magnetic field induced Wigner crystal in layer. The the fractional quantum Hall regime. At Interelectron spacing : scattering is low fields, the quantum fluctuations 1 short range dominate the Coulomb correlations and 126 A 182 A in this case. the Integer Quantum Hall Effect (where a “ ^ « ; In contrast, @ ns = 2 x1011 cm'2 = Pxv = h/ve2 and pxx ->0, v is an integer) is @ ns 9.6 x1010 cm'2 the I I I - V observed when weak disorder pins the Wigner-Seitz radius : heterostruct Fermi level in the gap between Landau ures have a levels. As the field is increased further, 9 9 dopants the electrons behave as a correlated ' “ b separated quantum liquid which exhibits the Critical concentration for from the Fractional Quantum Hall Effect (where pxv t w o - quantum cold melting : = h/ve2 and v = p/q and p and q are (0.92- 1.59) x 1010 (0.43 - 0.70) x 1010 dimensional integers and q is odd). A textbook » 1 layer by a n = ------r example of these phenomena is shown in * tt{rc a ,y cm'2 cm'2 spacer layer Fig. 2. Transitions to an electron solid a n d t h e phase are possible depending on which where rc = 37 ± 5 scattering is phase has the lowest ground state long range. energy. Compelling evidence for the Other than the physical parameters of the Table 2 shows a comparison of these magnetic field induced Wigner solid have material, it is possible to choose a samples with those used in the study of been provided by electrical, radio­ system which, by its epitaxial layered magnetic field induced Wigner crystal frequency and optical magneto-transport growth, can enhance the formation of from the point of view of "inherent experiments near filling factor 1/5, 2/7 in the Wigner crystal. It is known that the disorder". n-type GaAs/AIGaAs heterostructures coupling between two electron systems and 1/3 in similar p-type samples [161. separated by less than the interelectron Table 2 distance favors Wigner crystallization Relative Disorder in Very High Mobility 117-181. Here, we will look at two Si-MOSFETs and GaAs-AIGaAs systems: Si-Si02 field effect transistors Heterostructures o r Si-MOSFETs (metal oxide Si-MOSFETs GaAs-AIGaAs semiconductor field effect transistor) and p-type Si-SiGe-Si heterostructures. n, (cm'2) 1-3x10'° 1012

SAMPLES π* / ns 0.1-0.3 10-15 A number of Si MOSFETs grow n in Russia were studied in detail. The electron m obility in these samples is an setback distance d 50-100 A -500 A order of magnitude larger than that of commercial Si-MOSFETs and 2-4 times larger than that of the best Si-MOSFETs setback/Bohr radius: 2.5-5 5 grown for research purposes. This d/an mobility was achieved by careful In the dilute limit, where impurity processing to avoid highly diffusive scattering dominates, the Si-MOSFETs contaminants such as Na and K ions, and and the GaAs/AIGaAs are equivalent repeated growth and stripping of the system s. Fig. 2 Textbook example of the Integer and thermal oxide to ensure a smooth interface. The samples have the following Fractional Quantum Hall Effects. From RESULTS A. Chang, The Quantum Hall Effect, low temperature peak mobilities: Si-15: μ ed. R. E. Prange and S. M. Girvin, = 7.1 x 10“ cm2/Vs, Si-5: /y = 4.3x10d In probing the dilute density regime Springer-Verlag, New York, 2nd Ed. (1990). cm2/Vs, Si-11: μ = 3.63x10d cm 2/Vs, below 1x10" cm2, a number of and Si-2: μ = 2.42x10d cm 2/Vs. By anomalous features were discovered in applying a bias to the Al top gate, the the magneto-transport measurements at carrier density can be varied from half-filled Landau levels (v = 5/2, 3/2).

La Physique au Canada mars à avril 1 9 9 6 6 3 Some of these are shown in Fig. 3: valley degeneracy which is lifted by intervalley interaction and the asymmetric confinement potential (Δν = 6 2.5 2 2.4 K), and a large spin splitting which persists down to zero field (Δ, = 4 K) due to the large spin-orbit coupling [201.

Because the Fermi energy is comparable V /c m ) to these splittings, polarization effects will be important. While the ground state energetics of the liquid phase is sensitive to the polarization state, the solid phase is relatively unaffected by polarization due to the weaker exchange energy. Whereas the Monte Carlo simulation for a pure system suggests that the transition to the Wigner crystal should occur at r, = 37 19), a fixed node and variational Monte Carlo simulation incorporating the Fig. 4(b) The carrier density dependence of valley degeneracy and impurity effects in the activation energy and the threshold electric field for sample Si-MOSFETs yield a partially polarized Si-2. The critical density is n_ = fluid to a fully polarized solid transition at 10.05 x 10'° cm 2. Fig· 3 The longitudinal and Hall resistances r, = 7.5 |21|! It should be possible then as a function of magnetic field for to observe the quantum Wigner crystal at sample Si-5 at carrier density n, = 15 9.33 x 10'° cm 2. zero magnetic field in very high mobility Si-MOSFETs! > ( a ) r ~ f • Instead of regular Shubnikov-de Haas a 5 oscillations obtained from measuring Theoretically, there is little doubt that, the resistance along the sample as a for zero disorder and zero temperature, the 2D electron gas will crystallize into a -5 r = 3 5 m K function of magnetic field, the maxima - . J in the Shubnikov-de Haas oscillation at Wigner lattice upon lowering the density. η » = θ .3 2 half-filled Landau levels become It is also accepted that, in the limit of -15 strong disorder, single-particle - 1.0 -0.5 0.0 0.5 1.0 enormous with resistances ~ 10,? ohms Current (nA) depending on the carrier density. The localization will set in. Our samples with resistance goes back down to the level minimal disorder provide an intermediate of a few ohms as the magnetic field is regime where a collective insulating state swept into the quantum Hall minima at like the pinned Wigner solid 1221 or the Fig. 5(a) The current-voltage characteristics pinned charge density w ave [231 might at carrier density na = 8 .3 2 x 1 0 '° filling factors v = 2 and 1. cm 2 and zero magnetic field for exist. The study of the zero field sample Si-2. • If the magnetic field is kept at one of longitudinal resistance as a function of the SdH oscillation maxima, and the carrier density and temperature led to the current-voltage (l-V) characteristics are following experimental observations: measured at constant density, the result is a sharp non-linear l-V curve • Below a critical carrierdensity nsr ~ 10" with a low threshold field value which cm2, the longitudinal resistivity increases as the carrier density is exhibits insulating behavior decreased: characterized by an exponential rise shown in Fig. 4(a) and a negative • The resistance at the SdH maxima is slope in the temperature dependence thermally activated below threshold dR../3T. with p„ oc ■ ' The activation energy Fig. 5(b) The broadband noise voltage increases linearly with decreasing measured between potential contacts as a function of the density. source-drain current.

• While the large resistance is developing along the sample, the Hall resistance across the sample remains metallic as it does in the high density regime.

These surprising observations (191 led us to believe that the two-dimensional electron gas was undergoing a series of re-entrant transitions from an insulating state characteristic of some new phase to the non-interacting gas of the integer quantum Hall regime. In view of the results attributed to a magnetic field induced Wigner crystal near filling factor Fig. 4(a) The longitudinal resistivity as a 1/5 in GaAs/AIGaAs heterostructures, we function of carrier density for looked into the conditions required for sample Si-2 at zero magnetic field. Wigner crystallization in Si-MOSFETs and found them to be quite favorable in theory. The large effective mass m* = • In the temperature range 100-650 mK, 0.19 m0 and the low dielectric constant the temperature dependence of R„, can e = 7.7 set Si-MOSFETs apart from be described by RK, oc θ λλ1 where the Fig. 5(c) T w o in d e p e n d e n t spectral GaAs-AIGaAs heterostructures; in activation energy Δ drops linearly to measurements of the narrowband noise driven by the DC current. addition, Si-MOSFETs feature a two-fold zero at nsc as shown in Fig. 4(b).

64 Physics in Canada March/April 1996 • The current-voltage characteristics phonon-assisted tunneling to states which and an accompanying lattice distortion. exhibit a sharp drop in áV/91 above a are close in energy. The tunneling As in superconductivity, there is a gap in threshold electric field E, as shown in distance to a state within kBT of the Fermi the single-particle excitation spectrum, a Fig. 5(a). energy increases with decreasing collective mode described by a complex temperature. This variable range hopping order parameter, and a phase whose time • The threshold field goes to zero process has a characteristic power law and spatial derivatives are linked to smoothly at nsc as shown in Fig. 4(b). dependence of the resistivity on the electric current and condensate density. The data can be fitted well by a power temperature: p(T) = PoexpfTo/T)* where x Both amplitude and phase fluctuations law E, « ônsr where γ = 1.7-1.8 = 1/3 for single particle localization in 2D can occur but whereas the amplitude and δη, = (nsc-ns) (see Fig. 6). More without Coulomb interaction |25|. mode has a gap, the phase excitations accurate measurements have actually Experimentally, we cannot fit our data to are gapless. Pinning is a central concept revealed a small discontinuity at nsc variable range hopping but observe an in CDW physics as the translational pointing to a first order transition |24|. activated temperature dependence with x symmetry is broken by electrostatic = 1; more recent results, in similar potentials caused by impurities and grain • The dependencies of the activation samples, have provided evidence for a boundaries which serve to pin the energy and the threshold field on Coulomb gap (x=1/2) in the density of collective mode. The CDW systems are carrier density is sample independent. states at the Fermi energy, in an composed of normal electrons coexisting However, the critical carrier density is intermediate temperature range (26|. In with a condensate and scattering with lower for higher mobility (less SPL, the threshold conduction is the normal electrons reduce the disordered) samples. associated with the breakdown of coherence length. Among the transport localized states when βΕ,ξ0 (where E, is properties associated with the dynamics • The sharp rise in conduction is the threshold and ξ0 is the localization of the collective mode are (1) non-linear accompanied by a steep increase of length) is comparable to the Fermi energy electrical conduction with a threshold the broadband rms-noise voltage E,. For the low threshold field at electric field, (2) a metal-insulator or a (VN) as a function of current (see δη, = 0.1 x 1010 cm 2 and EF = 6 K, the metal-semiconductor transition below a Fig. 5(b)). The broadband noise was localization length would have to be distinct melting temperature measured at two nearest potential longer than the sample itself i.e. c„ = 6 accompanied by a periodic lattice contacts in the 1-300 kHz frequency mm. The threshold field typical of SPL is distortion incommensurate with the ba nd. of order 2.9 x103 V/cm [27] for our underlying lattice, (3) anomalous experimental conditions. Our threshold microwave conductivity, (4) dc and ac • The narrowband noise shown in Fig. fields are five orders of magnitude excitations dominated by the collective 5(c) has a reproducible frequency smaller. A series of capacitance mode dynamics, and (5) strong frequency spectrum which shifts to higher measurements on these samples also dependent response in a broad frequency frequency as the driving current is show that the effective area for range. In studying such systems it is increased. The maxima in the signal conduction does not change as the carrier essential to examine intrinsic defects due amplitude occur at frequencies which density is decreased |28|. Our to thermal fluctuations as well as can be related to the 2D electron experimental results are therefore not defects, vacancies and dislocations lattice constants. consistent with s i ng I e - pa r t i c I e induced by quantum fluctuations as they localization. However, single-particle are believed to play an important role in localization is expected to become the melting transition. dominant in the regime where the number of carriers has been decreased so much What drives the conduction in the CDW? that it is equal to the number of pinning Let us imagine that a CDW is pinned by impurities in the oxide layer. The more the electrostatic potential well of an rapid increase of the threshold field below impurity . If an external electric field is 7.5x10'° cm2 is a precursor of this applied, the CDW deforms around the phase. pinning center but electrons remain constrained by the phase coherent CDW. Let us consider the data in the The electrons which have not condensed framework of a pinned Wigner crystal. By in a CDW can still contribute to drawing an analogy to a charge density conduction by thermal activation across wave (CDW), it may be easier to the gap but because of their low density understand the experimental results. the resistivity of the pinned CDW is high. Charge density waves are predominantly At low temperatures when all electrons a one-dimensional phenomenon although have frozen out, the activation energy is they also occur in materials with two or related to the energy required to change three-dimensional band structures |29|. the phase of the local CDW in a coherent Chain and layer structures in which CDW domain by 2tt. Above a critical threshold Fig. Θ The dependence of the threshold transitions have been studied include field, the entire CDW can become electric field on the carrier density organic conductors such as TTF-TCNQ depinned and slide coherently in the variation n^-n, for sample Si-2. The solid line is a fit to E, = δη,' 8 while (tetracyanoquinodimethane) and linear direction opposite to that of the applied the dashed line is the theoretical chain inorganic materials such as TaS3, electric field. The differential resistivity dependence E, = δη,' NbSe3 and blue bronze K03M o 0 3. In these drops sharply giving rise to sharp non­ materials, the electron density is spatially linear l-V characteristics. The larger the These zero magnetic field transport dependent consisting of the unperturbed number of pinning impurities, the greater signatures are similar to those observed in electron density in the absence of the loss of phase coherence and the the classical Wigner solid of electrons on electron-phonon interaction given by p 0 smoother the l-V characteristics. As the helium and the magnetic-field induced = n/kf in one-dimension, and a collective CDW slides past stationary impurity Wigner solid near fractional filling factor mode formed by electron-hole pairs potentials, the voltage noise generated 1/5. In the very high mobility samples, involving the wave vector q = 2kr : by the perturbation of the impurity these features are also seen at filling potential will depend on the current, the factors 3/2 and 5/2 at magnetic fields pU) = Po+p^os&k, r+Φ ) carrier density and the period of the below 5 Tesla. But let us forget this for a CDW. The size of the phase coherent moment and play devil’s advocate. Could where kf is the Fermi wavevector and Φ domains is defined by the correlation this be simply a manifestation of single­ is the phase. The collective mode results length which can be measured from the particle localization (SPL)? In disordered from the pairing of electron and holes on transverse shear modulus, the threshold semiconductors at low temperature, either side of the Fermi suface to form a field, the interelectron spacing, and the transport takes place by means of condensate called a charge density wave carrier density.

La Physique au Canada mars à avril 1996 65 In analogy to CDW systems, the electron frequency shifts with current, there is no solid forms in the presence of a simple relation that can be applied to link neutralizing background charge which the results to a hexagonal or triangular fixes the density when the potential lattice symmetry. It is likely that part of energy between the localized electrons the current is provided by "uncondensed" dominates all other energies in the electrons hopping beyond the lattice. problem. In most samples, the solid phase coexists with uncrystallized electrons. However, the phase coherence length remains large compared to the interelectron spacing in the electron solid (in GaAs: 4.8/ym > > 100r, ~ 300 Λ). Thus quantum depinning and defect waves or dislocation pairs are possible in electron systems but unlikely in CDW. The type of pinning, weak or strong, will depend on the location, nature (acceptor or donor), and number of pinning impurities. A successful model for the conduction mechanism in the Wigner solid has been Fig. 7 Conductivity versus applied electric developed by Chui. The model assumes field for sample Si-5 at n, = 6.69 x 10'° cm 2. The solid lines are a that the charge carrying excitations are single fit to the data at both bound dislocation pairs. A single temperatures using phase slip model. dislocation can be visualized as a shift of the electrons from equilibrium position What information can we get about the which can be described by a collective transport of depinned domains Fig. 8 Phase diagram for the two­ displacement field. A dislocation pair dimensional electron system showing above the threshold field? By using the the critical density versus the sample consists of two dislocations with approach of elastic theory [33] as applied peak mobility. displacement fields in opposite directions; to charge density waves in the weak there is a net displacement of charge pinning limit, we can estimate the By studying samples in a wide range of between the dislocations and the motion correlation length or domain size, L0 as mobilities and carrier densities, we have of this locally altered density is possible (/ίΓ3/(2πθη,Ε,))Λ where KT is the been able to probe the effect of with resulting conduction. This is transverse shear modulus, and a is the "disorder" on the development of the equivalent to the phase slip model in interelectron spacing. The experimental insulating phase. Fig. 8 shows the phase CDW. dependence of the threshold field on the diagram for the formation of the carrier density shows that the correlation collective insulator phase or quantum If we review the experimental results, the length diverges as (δη,)09 and thus L0 Wigner solid confined between the similarities between the pinned charge becomes smaller as the density is metallic state above the cold melting density wave and the pinned electron decreased, driving the system towards boundary ncm (full line) and the Anderson solid are striking. There is a critical single-particle localization. Single-particle insulator or the regime of single-particle density and a critical temperature below localization does have "its place in the localization below the nS|, boundary. By which the insulating phase appears. The sun" in the phase diagram. using a calculation by Gold 1341 for the transition at the critical carrier density is mobility of Si(100) inversion layers, we weakly first order in character. The non­ The activation energy and the threshold obtain a satisfactory model for the peak linear l-V characteristics can be field can be used to extract some mobility versus carrier density in our interpreted as showing that at small characteristic length scale for the samples. The number of impurities n,- is a currents the Wigner crystal is pinned by electron solid, e.g. the elementary better indicator of disorder as the the neighboring impurities until the crystallite size of the pinned Wigner solid. impurities are the main source of threshold field is exceeded and the For a carrier density n, = 8.4x10'° c m 2, scattering at low densities (below Wigner crystal slides. Over the range of the sample typically consists of pinned 2x10" c m 2). The boundary for SPL is densities 7.2 x 10'° - 1.0x 1 0 " cm2 the crystallites approximately 0.7 μπη x0.7 estimated from n, and depicted by a short threshold field decreases as E,»=(nc-ns)s /vm in size each containing about 300 dashed line. This is the highest estimate where β= 1.7-1.8. This is in agreement electrons with an interelectron distance ~ for SPL in our samples where the surface with a depinning mechanism involving 400 Â! roughness is much lower than that used the creation and separation of dislocation to calculate n, and nsn. The full triangles pairs [30]. The theoretical model agrees The generated broadband noise shown in indicate nSPl estimates if the domain well with the experimental results as Fig. 5(b) is also consistent with depinning length LD is tw ice the interelectron shown in Fig. 6. The fact that the sub­ of the Wigner crystal or coherent defect distance Ln = 2a. The solid line is the threshold activation energy below 100 motion above threshold. The narrowband calculated dependence of the cold mK is much smaller than that above is noise should yield frequency peaks melting density on n. using the mean consistent with e xte n d e d defect related to the principal lattice spacings. If square displacement as a function of n, conduction [311. If one ignores quantum we assume that the electron lattice and an estimate of the cold melting coherence effects, the motion of extends across the entire 2D layer of density as n, goes to zero. The extended defects and in particular that of w id th w and that the total current I is calculation of the transition from a dislocation pairs is equivalent to phase only provided by the sliding lattice, the polarized WS to a partially polarized liquid slippage in a charge density wave [32|. spectral maxima will be related to the at rs = 10 (n, ~ 7.65x10'° c m 2) is The σχχ versus electric field curves can be principal lattice spacing η, as η, = represented by a bar 1211 and is in fitted to a phase slippage equation of the l/le^ivri,). For a hexagonal lattice sliding agreement with the data for Si-5 and Si- type: in a random field of point defects, η, = 11. This phase diagram also explains b, η2 = \3 b, and η3 = 2b where b is why such a collective phase was not σχχ = (l0//cE)eli/kTI sinh [neE/x/kT| the distance between nearest neighbor observed by other groups using lower electrons. Experimentalists have been mobility samples and suggests that we where lc is the intercontact distance, l0 is urged to try this extremely difficult should be looking for a material system related to the current created by a single measurement as it could provide the with as good if not better material phase slip and /, is a characteristic phase definitive signature for lattice ordering of parameters than the high mobility Si- slip length. The value of I, obtained from electrons- the "smoking gun” for Wigner MOSFETs studied here. Thus there is the fit in Fig. 7 is 0.2 3 μπ\, or ten times crystallization. Although there are peaks mounting experimental evidence for a the interelectron spacing. in the narrowband spectrum and the low temperature transition to a collective

66 Physics in Canada March/April 1996 insulator at zero magnetic field in high have a large effective hole mass, 0.42 m0 observed in larger wells but rather the mobility Si-MOSFETs. This collective w hich is tw ice that of electrons in the Si- population of the heavy hole and the insulating phase has the transport MOSFETs. This has been checked in our light hole ground subbands. This characteristics of a Wigner solid. samples by analysis of the low-field interpretation is borne out by k«p Shubnikov-de Haas oscillations and by Luttinger Hamiltonian calculations The temperature dependence of the zero cyclotron resonance [39-411. Although 1411. field resistance as a function of carrier the dielectric constant ε ~ 12.6 is similar density is also host to some more to that of GaAs-AIGaAs heterostructures, fundamental physics: that of scaling and the symmetric confinement of holes in Table 3 universality. For more than two decades, the SiGe well can lead to coupled 2D The MBE-grown Si-Si08,Ge013-Si it has been generally accepted that, at hole gases. As pointed out in Table 1, at Heterostructures zero magnetic field, all states are a carrier density of 2x10" cm2 in Si- localized in a two-dimensional system for SiGe heterostructures, the Wigner-Seitz an infinite sample as T—>0 1351. In radius is identical to that in Si-Si02 and contrast, a three-dimensional system can the quantum cold melting critical density sustain a metal-insulator transition is twice as large because of the larger because the electrons are localized only effective mass! when the Fermi energy lies below a mobility edge Ec. The conventional 10s wisdom in 2D systems has recently been questioned as a result of a number of (a) experimental results in superconducting thin film s, and in high-m obility Si- MOSFETs 136-371. In addition, a io2 % theoretical study of noninteracting 2D % n=0.46xI0l0cni‘* ...... 12.4x10'° c m 2 electrons in a model disorder potential with a random set of special scatterers \ showed that, at zero magnetic field, the io' \ system is localized only when Er < Ec 1381. In material systems where the range ji» Y of the scattering centers is short (as in -c MOSFETs), similar to Azbel’s model Cl potential, a "true" zero magnetic field 10° metal-insulator transition may be allowed in the limit of zero temperature. The resistivity as a function of temperature • There is a large peak in the over a wide range of densities (7.12 -> longitudinal resistance at filling factor 10 ' 13.7x10'° c m ’ l in a high-m obility Si- 3/2 followed by a deep minimum at MOSFET sample (Si-12b; μ ιη„, = filling factor v = 1. The Hall resistance 3.0 x 104 cm2/Vs) can be made to overlap is not anomalous at the half-filled by scaling along the temperature axis. Landau level and displays a well The resistivity can be represented in 10* developed plateau h/e2 when the terms of a ratio T/T0 where T0 depends 1 0 ' 10 ' 10° 1θ' 10° TIT, longitudinal resistance is at its only on the density. The data collapses minimum. on two separate curves one for the • For the narrower 90 and 65 A wells, insulating side of the transition and the Fig. 9 Resistivity versus T/T0 where T0 is the there are large longitudinal resistance other for the metallic side as shown in scaling parameter. The open symbols peaks at both v= 3/2 and 5/2, re­ correspond to the insulating side of Fig. 9. One of the signatures of a phase the transition while the closed ones entrant with deep minima at v = 1 transition is the scaling of an appropriate correspond to the metallic phase. and 2. physical parameter. It would seem then • The temperature dependence of the that the results are in agreement with current-voltage characteristics taken at Azbel’s model but in contradiction with The Si-Si087Ge013-Si heterostructures v = 3/2 for the 65 Λ well reveal that that of Abrahams and co-workers; this were grown on an n Si (100) substrate the onset of the large resistance suggests that there is a "true" metal by molecular beam epitaxy. The maxima (> > h/e2) occurs around 500 insulator transition in the two-dimensional symmetrically-doped = samples were mK (see Fig. 11). electron system in Si at zero maqnetic grown on a 500 = A i-Si buffer and field. consisted of a 500 A Si layer modulation- doped with boron acceptors at 10,a cm 3 and a 300 A i-Si setback on each side of Si-SiGe-Si QUANTUM WELL a Si0 87 Ge013 quantum well of thickness STRUCTURES d . A set of samples was grown with d = 45, 65, 90 ando115 Λ. The cap layer The experimental results on high mobility consisted of 400 A of B-doped Si. This Si-MOSFETS have been reproduced in at is shown in Table 3. least four different laboratories around the world. However, there is only one The samples were patterned as Hall bar batch of such samples and it is very structures 10 mm long and 2 mm wide. difficult, without a large investment in Ohmic contacts were made using Al time and manpower, to fabricate more of evaporation and annealing below the these. We have thus turned to eutectic point. pseudomorphic Si-SiGe-Si hetero­ structures which are grown, either by A number of unexpected results were molecular beam epitaxy or ultra-high obtained in these samples: vacuum chemical vapor deposition • The SdH oscillations in the 1 15 A well Magnetic Field (Tesla) techniques, in a large number of are typical of two subband population laboratories and may be better suited for as shown in Fig. 10. These are not Fig. 10 Longitudinal resistance as a function studying Wigner crystallization. The of magnetic field for different SiGe oscillations from two independent hole quantum well widths at T ■* 25 mK. important features of the p-type Si-SiGe- gases at each interface as was Si quantum wells are that the 2D holes

La Physique au Canada mars à avril 1996 67 200 The curves also appear to converge near We have only begun to explore the phase a critical resistivity of h/2e2. These diagram for the formation of a Wigner 190 features are similar to those observed in solid in two-dimensional electron and superconducting thin films of Bi as a hole systems. The mapping of the phase 100 function of thickness, and Si MOSFETs boundaries as a function of temperature, and GaAs-AIGaAs heterostructures as a density, magnetic field and disorder is a function of carrier density. Further study challenging task. As better samples of scaling parameters will require the become available, a fuller story on the variation of the density in the Si-SiGe-Si richness of the dilute density regime can heterostructures. From other work [42|, be w ritten . 20 mK we know that the critical density in these 460 mK - systems is slightly above our fixed density. We must also investigate the 40 mK ACKNOWLEDGMENTS -150 80 mK role of disorder in the onset of these 30 mK I wish to acknowledge fruitful 88. 70, 48 mK transitions by studying higher mobility 10 mK collaboration with a number of and hence higher Ge content samples. -100 -50 0 50 100 150 colleagues: from NRC- Don Brown, John Current (πΑ) Campbell, Simon Deblois, Pawel Hawrylak, Jennifer Lam, J.-P. Noël, and Fig. 11 Current voltage (l-V) characteristics Duncan Stewart, from the University of as a function of temperature for v = Oklahoma- John Furneaux and Sergey 3/2 at B = 7.75 T for the 85 A well. Kravchenko, from SUNY in Buffalo- Bruce McCombe and his group and, finally, • Similar results are shown in Fig. 12 for from the Institute for High Temperature the 90 Á well with the sub-threshold Physics in Moscow- Vladimir Pudalov resistance at v = 3/2 increasing by who provided the Si-MOSFETs and was two orders of magnitude below 500 the driving force behind that work. mK. the inset shows the thermal activation of the differential resistance where dV/dl « e ^ with Δ = 0.47 K REFERENCES in the temperature range above 100 mK. 1. E. Wigner, Phys. Rev. 46, 1002 (1934). Although these results have been taken 2. R.S. Crandall and R.W. Williams. at a fixed density — 2x10" c m 2, the Phys. Lett. A 34, 404 (1971). basic features of large longitudinal resistances at half-filled Landau levels, Fig. 13 Temperature dependence of the 3. A.V. Chaplik, Sov.Phys. JETP 35, non-linear l-V characteristics with low longitudinal resistivity in a vanishing 395 (1972). threshold fields, and thermal activation of magnetic field for different SiGe the resistance are very similar in nature quantum well widths. 4. A.S. Rybalko, B.N. Esselson, and Y.Z. to those in the Si-MOSFETS. In the light Kovdrya, Sov. J. Low Temp. Phys. 5, of the scaling behavior of the zero 450 (1979). magnetic field resistance in Si-MOSFETs, CONCLUSION 5. C.C. Grimes and G. Adams, Phys. we have also looked at the temperature The work on Si-MOSFETs has provided a Rev. Lett. 42, 795 (1979). dependence of the longitudinal resistance phase diagram for the formation of a at zero field for different well widths. quantum Wigner crystal at zero magnetic 6. R. Mehrottra, B.M. Guenin, and A.J. field as a function of disorder. It was also Dahm, Phys. Rev. Lett. 48, 641 30 established that a fully spin-polarized (1982). Wigner crystal could exist re-entrantly with a partially polarized quantum liquid 7. F. Gallet, G. Deville, A. Valdes, and or gas in the quantum Hall effect regime F.I.B. Williams, Phys. Rev. Lett. 53, in very high mobility samples only. The 588 (1984). study of the re-entrant insulating phase in semiconductor heterostructures has also 8. G. Deville, J. Low Temp. Phys. 72, I o led to the definition of a new type of 135 (1988). « insulator, "the Hall insulator" 1431, for i which the Hall resistivity remains metallic 9. D. Ceperley, Phys. Rev. B 18, 3126 while the longitudinal resistivity becomes (1978); B. Tanatar and D. Ceperley, infinite. The system par excellence to Phys. Rev. B 39, 5005 (1989). study the Wigner crystal state is one where the effective mass is large, the 10. For a review see Physics of the Electron Solid, edited by S.T. Chui, dielectric constant and the amount of International Press Inc. Boston disorder are small, the carrier density is DO 0 1 0 2 0 3 0 4 0 5 0 5 (1994). tunable and the material system imposes Temperature (K) some sort of inherent coupling either 11. K. Kajita, Jpn. J. Appl. Phys. 25, w ith non-degenerate valleys as in Si- Fig. 12 Temperature dependence of the 1943 (1987); Surf. Sci. 196, 29 differential resistance for the 90 A MOSFETs, or by lifting the degeneracy (1988). well at v = 3/2 and B = 7.95 T. The between the symmetric and anti­ inset shows activated behavior in the symmetric states through the valence 12. H.-W. Jiang and A.J. Dahm, Phys. higher temperature scale. band anisotropy as in the Si-SiGe system. Rev. Lett. 62, 1396 (1989); Surf. Finally, there is now mounting Sci. 229, 352 (19901. As shown in Fig. 13, there is a transition experimental evidence that the from an insulating phase where p_ Abrahams-Anderson-Licciardello- 13. E.Y. Andrei, G. Deville, D.C. Glattli, decreases with temperature for the 65 A Ramakrishnan theory for which a metal- F.I.B. Williams, E. Paris, and well to a metallic phase where p„ insulator transition in an infinite 2D B. Etienne, Phys. Rev. Lett. 60, 2765 decreases> with temperature for the 90 A system, at zero magnetic field as T-»0 is (1988). and 115 A wells. This is consistent with forbidden, is inappropriate in 2D systems the fact that the carrier density is with short range scatterers. decreasing with decreasing well width. (continued on page 71)

68 Physics in Canada March/April 1996 NOUVELLE SOURCE DE PLASMA POUR LE TRAITEMENT DES MATÉRIAUX: MAGNÉTOPLASMA À ONDE DE SURFACE

par Joëlle Margot, Groupe de Physique des Plasmas, Département de Physique, Université de Montréal, C.P. 6128, Suce. Centre-ville, Montréal, Québec H3C 3J7, adresse électronique: [email protected]

INTRODUCTION capacitive. Bien que ce type de plasma Pour notre part, nous avons souhaité soit employé de façon routinière dans la capitaliser sur l’expérience que nous avons Au cours des vingt dernières années, on a fabrication des microcircuits, entre autres des plasmas produits par des ondes de vu croître de façon considérable l'emploi parce qu'il permet le traitement simultané surface, pour produire une nouvelle source des plasmas pour le traitement des de plusieurs substrats, il souffre de sévères avec des caractéristiques comparables à matériaux aussi bien dans les secteurs de limitations. D'une part, la densité de celles des plasmas précédemment décrits. haute technologie, comme par exemple en particules chargées est faible (typiquement Dès 1992, nous avons mis sur pied un microélectronique et en photonique, que 109-1010 ions par cm3) et d'autre part, ce prototype de réacteur destiné à la gravure dans les industries plus traditionnelles type de source ne permet pas un bon de matériaux (RCE4). Son schéma est (e.g., métallurgie et textile). Il faut se contrôle du flux d'ions vers la surface. Or, présenté sur la figure 1. rappeler que dans le passé, les applications il s'avère qu'un tel contrôle est devenu des plasmas au traitement des matériaux nécessaire pour atteindre l'anisotropie de se sont développées sous l’égide de la gravure recherchée ainsi que l'optimisation communautédesutilisateurs, ceux-ci ayant des autres paramètres de gravure. De fait appel aux plasmas pour pallier les nouvelles sources de plasma ont vu le jour limitations des méthodes conventionnelles. pour mieux répondre aux objectifs de plus Les percées dans le domaine se sont donc en plus exigeants dans ce domaine. En appuyées sur des moyens plus ou moins bref, il s'agit de produire une source de empiriques de sorte que le fondement plasma relativement dense tout en scientifique de ces applications demeure permettant de contrôler adéquatement le encore peu substantiel. Le progrès que flux d'ions frappant la surface, et ceci l'on peut attendre d'une telle démarche est indépendamment du mécanisme de par conséquent limité et il est devenu création du plasma. Une source telle que nécessaire de mieux comprendre le la fameuse décharge dite de résonance fonctionnement des sources de plasma cyclotronique électronique (RCE) en est un utilisées, d'en concevoir de nouvelles et de exemple. Il s'agit d'une source micro-onde Figure 1. Schém a du réacteur RCE4 modéliser de façon adéquate à la fois le (2,45 GHz) fonctionnant à très basse (magnétoplasma à onde de surface) plasma et l’interaction plasma-surface si pression (10 mtorr et moins) et dont la l'on veut relever les défis posés en densité d'ions peut atteindre selon les Le réacteur est alimenté par un plasma à microélectronique et en photonique. Bien conditions plusieurs 10" cm 3 avec un onde de surface à 2,45 GHz produit dans sûr, cette recherche est de nature tout à degré d'ionisation souvent supérieur à 1 %. un tube de silice fondue (quartz) de 1 5 cm fait fondamentale et elle requiert une Le fonctionnement à très basse pression de diamètre. Ce tube pénètre dans une expertise en physique des plasmas, aussi est rendu possible grâce à la présence d'un enceinte métallique de 28 cm de diamètre bien en modélisation qu'en caractérisation, champ magnétique statique (environ 875 le long de laquelle sont disposées plusieurs et une interaction étroite avec les gauss) qui permet de confiner les particules fenêtres destinées à visualiser le plasma et spécialistes des procédés et de la chargées et assure également le à insérer des diagnostics. Un ensemble de caractérisation des surfaces. Tout ceci a mécanisme de transfert d'énergie onde- 1 2 soléno'ides est disposé le long du tube stimulé au cours des dernières années des plasma. Les avantages de ce type de et du réacteur. L’espacement entre les activités de recherche portant sur la plasma sont notoires. Ainsi, la grande bobines a été choisi de sorte que le champ physique des plasmas dits froids et des densité de particules chargées permet magnétique demeure homogène sur plasmas réactifs dans de nombreux d'assurer un taux élevé de gravure assistée environ 70 cm, incluant la source. Cet laboratoires à travers le monde. par les ions. Aucune électrode interne aspect de la conception du dispositif n'étant présente dans la décharge, les expérimental est basé sur le fait que les Pour notre part, dans le contexte général risques de contamination sont minimisés. études de distribution en vitesse des ions présenté ci-dessus, nous avons mis au La différence de potentiel entre la surface dans des réacteurs de type RCE ou hélicon point une source de plasma originale, gravée et le plasma est en général montrent que le mouvement des ions est basée sur la propagation des ondes de inférieure à 20 volts, une valeur très en- très influencé par l’orientation des lignes surface et à laquelle on adjoint un dessous de celle rencontrée dans les de champ magnétique: les ions ont confinement magnétique. Les propriétés décharges capacitives. Enfin, la pression tendance à suivre ces lignes. Or, pour de cette source sont mises à profit pour très faible permet de limiter le nombre de atteindre un bon contrôle du mouvement graver des couches minces à des collisions subies par les ions dans la gaine des ions vers la surface à traiter, il est dimensions sous-micrométriques. La de plasma. Ainsi, on préserve mieux la nettement préférable que ceux-ci frappent conception de cette source, sa directionnalité du mouvement des ions la surface à la normale. L'utilisation caractérisation et sa modélisation dans la gaine ce qui favorise l'anisotropie fréquente de lignes de champ divergentes constituent un volet important des de gravure. dans les magnétoplasmas est un obstacle activités du Groupe de Physique des à la recherche de l'anisotropie en gravure Plasmas de l'Université de Montréal. Dans D'autres types de décharges similaires à la de couches minces. cet article, nous décrivons brièvement les source RCE ont également été proposées propriétés du plasma ainsi produit ainsi que comme, par exemple, le plasma hélicon Bien que les études que nous avons l'influence sur les paramètres du plasma de dont le principe de fonctionnement menées jusqu'à présent se soient la présence d'un substrat. Nous demeure tout à fait comparable. Ce plasma essentiellement limitées à une fréquence examinons également les performances de est produit à des fréquences radio (e.g., micro-onde (2,45 GHz), le plasma produit ce plasma pour la reproduction de motifs 13,56 MHz) et nécessite également un par onde de surface présente l'avantage sous-micrométriques (0,2 /rm) dans du champ magnétique; on note cependant notoire de pouvoir fonctionner à n'importe tungstène. que ce champ peut être beaucoup plus quelle fréquence. C'est d'ailleurs cette faible que celui employé pour les décharges extraordinaire flexibilité, bien adaptée à des RCE. Pour des conditions comparables de études paramétriques, qui a permis à ce NOUVELLES SOURCES DE PLASMA POUR pression, de diamètre de tube à décharge type de plasma d'acquérir ses lettres de LA GRAVURE EN MICROÉLECTRONIQUE et d'intensité de champ magnétique, la noblesse, particulièrement en ce qui concerne la modélisation des décharges de La source de plasma majoritairement densité de particules chargées est comparable dans les deux types de plasma. haute fréquence (HF). employée en gravure des matériaux, pour prendre cet exemple, est la décharge

La Physique au Canada mars à avril 1996 69 CARACTÉRISTIQUES DU MAGNÉTOPLASMA évidence par photo-détachement induit par l'aluminium et de l'acier à plus haute À ONDE DE SURFACE laser une forte concentration d’ions pression (7 mtorr). négatifs, leur densité étant supérieure à La figure 2 montre un exemple de celle des électrons à des pressions de Outre son influence sur la concentration en distribution en vitesse des ions métastables seulement quelques mtorr. fluor atomique dans la décharge, la d'argon dans la direction parallèle à l'axe de présence d'un substrat modifie de façon la colonne de plasma dans un dispositif Nous avons utilisé une source similaire, importante celle du soufre moléculaire tel similaire à celui présenté ci-dessus (RCE5). mais de plus petites dimensions pour qu'illustré sur la figure 3 Ces mesures ont été réalisées au moyen effectuer une étude du bilan énergétique d'une méthode de fluorescence induite par de la décharge 11]. Nous avons ainsi pu Sur ce graphique est reportée la laser. montrer que le bilan énergétique s'améliore concentration de S2 en fonction de la position à partir du substrat pour différents lorsqu'un confinement magnétique est matériaux. On y remarque un appliqué à la décharge, comme on pouvait accroissement de la concentration de S2 s'y attendre, la présence d'un champ non seulement au voisinage immédiat du magnétique réduisant les pertes de substrat, mais également à grande distance particules chargées. Un modèle de de celui-ci. A partir de ces résultats ainsi magnétoplasma récemment élaboré |2) que de mesures complémentaires permet d'ailleurs de confirmer un certain effectuées en post-décharge temporelle, on nombre de nos observations. Cependant, a pu montrer que la présence d'un substrat, et particulièrement d'un substrat contrairement à ce qui est largement de tungstène, influence l'ensemble de la affirm é dans la littérature, le fait de chimie du réacteur, incluant le coefficient fonctionner à la résonance cyclotronique de collage de ses parois d'acier. En outre, électronique ne constitue pas un avantage nous avons pu mettre en évidence que le en termes de bilan d'énergie. En fait, plus soufre moléculaire est principalement le champ magnétique est intense, meilleur détruit par impact électronique • ikaftl est le rendement énergétique. Les valeurs contrairement à ce qui a été observé dans une décharge capacitive de type RIE mesurées de la puissance absorbée par Figure 2. Fonction de distribution en énergie (Reactive Ion Etching) [41, ceci résultant des ions métastables d'argon électron dans notre plasma ont été bien sûr du fait que le magnétoplasma est obtenues dans le réacteur RCE5 au utilisées pour démontrer que l'ensemble considérablement plus dense que la m oyen d'une méthode de des magnétoplasmas HF obéissent aux décharge de type capacitif. fluorescence induite par laser. Noter mêmes règles physiques; ainsi, pour des que les profils ne sont pas déconvolués pour tenir compte de conditions identiques de fonctionnement, GRAVURE SOUS-MICROMÉTRIQUE DU l'effet Zeeman et de la largeur de la le bilan énergétique demeure le même pour TUNGSTÈNE raie du laser. n’importe quel magnétoplasma HF. La source que nous avons conçue nous a On y remarque que les ions suivent une INTERACTION PLASMA-SURFACE permis d'effectuer, en utilisant un plasma distribution gaussienne centrée autour de de SFe, la gravure de motifs sous- zéro. Ainsi, pour un champ magnétique Nous avons étudié l'influence de la micrométriques de tungstène à des axialement uniforme, les ions ont une très pré sen ce d'un substrat sur les températures de substrat variant de -45° à faible vitesse de dérive axiale. À titre de caractéristiques en volume du plasma [3]. + 1 5° [5]. Ainsi, nous avons pu reproduire comparaison, nous avons représenté sur la des motifs de très petites dimensions (0,2 même figure les distributions de vitesse //m) sans faire appel à une polarisation obtenues dans des régions de champ externe du substrat. Dans une telle magnétique décroissant et croissant. Dans situation, les ions interagissant avec la le premier cas, les ions sont accélérés loin surface ont une énergie relativement faible, de la source alors que dans le second, les ce qui réduit les dommages causés à la Í ions ont tendance à revenir vers la source. •X surface. Une photographie de motifs de Ces résultats illustrent bien le rôle ■* 0,2 μτη est présentée sur la figure 4. La extrêmement important que joue la gravure demeure anisotrope tant que la configuration du champ magnétique I pression est inférieure à une valeur seuil, statique sur le mouvement des ions. La fonction de la tem pérature de la surface. conclusion évidente de ces résultats est Ainsi, pour une température de -20°, le que pour tirer tous les bénéfices de seuil se situe autour de 0,75 mtorr alors l'utilisation d'un champ magnétique de qu'il est plutôt de 1,5 mtorr lorsque la confinement, il est préférable d’avoir des température est abaissée à -45°. lignes de champ magnétique aussi uniforme que possible. Ceci permet de Figure 3. Densité de soufre moléculaire S, dans le plasma en présence de différents lim iter la dérive axiale des ions au minimum substrats. Le substrat est situé à -1 et donne à l'utilisateur plus de latitude pour cm sur l’abscisse de ce graphique. contrôler indépendamment du plasma le mouvement des ions vers la surface à Cette étude a été menée sur un plasma de traiter, par exemple au moyen d’une SF6 au moyen d'une méthode de polarisation auxiliaire (et maîtrisée) du fluorescence induite par laser et d'une substrat. méthoded’actinométrie résolue spatialement avec double procédure de normalisation; les Le magnétoplasma a été diagnostiqué au espèces examinées sont, d'une part, le fluor moyen de plusieurs méthodes incluant des atomique et, d'autre part, le soufre sondes électrostatiques, des ondes moléculaire S2, formé en grande acoustiques ioniques et diverses méthodes concentration dans ce type de plasma. Les spectroscopiques. Nous avons ainsi pu résultats de cette étude ont montré que le montrer que la densité des ions positifs fluor atomique est fortement consommé par pouvait atteindre localement 10'2 cm 3 le silicium, comme on s'y attendait, dans l'argon et la température des contrairementaux matériaux plusinertes vis- Figure 4. Photographie de motifs de tungstène électrons quelques eV. Dans un gaz à-vis des gaz fluorés, comme l'aluminium ou ayant 0,2 μτη de largeur, obtenus è partir d'une image par microscope comme le SF„ utilisé pour la gravure du l'acier inoxydable. Le tungstène, quanta lui, électronique. tungstène, on a obtenu des valeurs n'a pas une influence systématique sur cette comparables pour la densité et la consommation qui peut être aussi Les résultats obtenus montrent que notre température; on a également mis en importante que celle du silicium à basse réacteur possède d'excellentes pression (1 mtorr) ou comparable à celle de

70 Physics in Canada March/April 1996 caractéristiques. En particulier, le fait de 141 L. St-Onge, N. Sadeghi, J.P . Booth, 27. Y.C. Lee, C.S. Chu, and E. Castano, ne pas devoir recourir à une polarisation J. Margot et C. Barbeau, ” 0n the Phys. Rev. B 27, 6136 (1983). auxiliaire du substrat pour atteindre une formation and loss of S2 molecules in a anisotropie parfaite constitue un atout reactive ion etching reactor operating 28. S.V. Kravchenko, J. A. A J. Peren boom, majeur par rapport à d'autres types de with SFe", J. Appl. Phys., 78, 6957 and V.M. Pudalov, Phys. Rev. B 44, sources. Nous pensons que le fait que le (1995). 13513(1991). champ magnétique soit uniforme dans la I5| F. Bounasri, E. Gat, M . Chaker , M. 29. For a review see: G. Griiner, Rev. of région où se situe le substrat, est à Moisan, J. Margot et M.F. Rávet, Modern Physics, 60, 1129(1988). l'origine des excellentes performances de "Highly anisotropic etching of notre réacteur en termes de gravure. submicrometer features on tungsten", 30. S.T. Chui and K. Esfarjani, Phys. Rev. J. Appl. Phys. 78, 6780 (1995). Lett. 66, 652 (1991); S.T. Chui, Phys. CONCLUSION Lett. A 180, 149 (1993). Nous avons mis au point une nouvelle source de plasma dont les caractéristiques 31. K. Esfarjani, S.T. Chui, and Xiu Qiu, Phys. Rev. B 46, 4638 (1992). sont bien adaptées à la reproduction de The Physics of Dilute . . . by M. D'lorio motifs sous-micrométriques. Le travail que (continued from pg. 68) 32. F. Ya. Nad and P. Monceau, Phys. nous avons effectué s'est situé non Rev. B 46, 7413 (1992). seulement du point de vue des 1 4. H.W. Jiang, R.L. Willett, H.L. Stormer, D.C. Tsui, L.N. Pfeiffer and K.W. applications, mais également sur le plan de 33. B.G.A. Normand, P.B. Littlewood, and Phys. Rev. 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Shayegan, nous sommes convaincus que cette Phys. Rev. B 46, 13639 (1992). 36. Y. Liu, K.A. McGreer, B. Nease, D.B. approche est la seule qui soit valable pour Haviland, G. Martinez, J.W. Halley, améliorer notablement les procédés 17. K. Moulopoulos and N.W. Ashcroft, and A.M. Goldman, Phys. Rev. Lett. Phys. Rev. Lett. 69, 2555 (1992). assistés par plasma. 67, 2068 (1991). 18. L. Swierkowski, D. Neilson, and REMERCIEMENTS 37. S.V. Kravchenko, Whitney E. Mason, J. Szymanski, Phys. Rev. Lett. 67, G.E. Bowker, J.E. Furneaux, V.M. L'auteur tient à exprimer sa 240 (1991). reconnaissance à toutes les personnes, Pudalov, and M. D'lorio, Phys. Rev. B 51, 7038 (1995); S.V. Kravchenko, collaborateurs, stagiaires, étudiants et 19. M. D'lorio, V.M. Pudalov, and G.V. Kravchenko, J.E. Furneaux, techniciens, ayant été impliquées à divers S.G. Semenchinsky, Phys. Lett. A V.M. Pudalov, and M. D'lorio, Phys. 150, 422 (1990); M. D'lorio, titres dans les travaux résumés ci-dessus. Rev. B 50, 8039 (1994). En particulier, les contributions de MM. M. V.M. Pudalov and S.G. Semenchinsky, Chaker (INRS-Énergie et Matériaux) et M. Phys. Rev. B 46, 15992 (1992); 38. M. Ya. Azbel, Phys. Rev. B 45, 4208 S.V. Kravchenko, V.M. Pudalov, Moisan (Université de Montréal) sont (1992). vivement remerciées ainsi que celles de J. Campbell, and M. D'lorio, JETP Lett. 54, 532 (1991). Mmes C. Barbeau et I. Pérès et de Μ. E. 39. M. D'lorio, D. Stewart, D. Brown, J.-P. Gat (stagiaires postdoctoraux). L'auteur Noël, and J. Scott-Thomas, tient également à exprimer sa gratitude à 20. V.M. Pudalov, S.G. Semenchinsky, Proceedings of ICPS-22, ed. and V.S. Edel'man, Sov. Phys. JETP Mme A. Dallaire et Μ. M. Fortin (étudiants D.J. Lockwood, World Scientific, 62, 1079 (1985); V.M. Pudalov, S.G. de 2" cycle) et MM. F. Bounasri et L. St­ Singapore, 1544(1995). Semenchinsky, and V.S. Edel'man, Onge (étudiants de 3° cycle). Enfin, une JETP Lett. 41, 325 (1985). reconnaissance particulière est accordée à 40. M. D'lorio, D. 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Margot, "The of the Eleventh International 24. V.M. Pudalov and S.T. Chui, Phys. radial structure of a magnetically Conference on the Electronic confined surface wave plasma Rev. B 49, 14062 (1994). Properties of Two-Dimensional column", Phys. Plasmas, à paraître Systems (EP2DS-1 1 ), 449, 25. N.F. Mott, J. Non-Cryst. Solids 1, 1 (mai 1 996) Nottingham, August 1995. (1968). 131 C. Barbeau, L. St-Onge, J . Margot, 43. S. Kivelson, D.H. Lee, and S.C. Zhang, 26. A.L. Efros and B.l. Shklovskii, J. Phys. M. Chaker, N. Sadeghi et J.P. Booth, Phys. Rev. B 46, 2223 (1992). C 8, L49 (1 975); Whitney Mason, S.V. "On the mechanisms of S2 formation Kravchenko, G.E. Bowker, and J.E. and loss in high-density SFe plasmas", manuscrit en préparation. Furneaux, Phys. Rev. B 52, 7857 (1995).

La Physique au Canada mars à avril 1996 71 EVALUATION OF THE ACID DEPOSITION AND OXIDANT MODEL WITH OZONE AND SULPHUR DIOXIDE DATA FROM HIGH ELEVATION SITES

by C.M. Banic, R.S. Schemenauer, K.G. Anlauf and K.I.A. MacQuarrie Atmospheric Environment Service, 4905 Dufferin Street, Downsview, Ontario, Canada, M3H 5T4

ABSTRACT linkage between emissions of specific consist of a combination of horizontal pollutant species and the resultant impact transects up to 250 km for times of about Mixing ratios of 0 3, measured continuously of the reaction products of these species 1 hour and vertical profiles over specific at two high elevation (850 m-msl) sites on vegetation, animals, humans and surface sites taken once or twice per day, and one valley (250 m-msl) site in southern climate. To a large extent man's influence the CHEF data provide continuous hourly Quebec, Canada, during the summer of on the environment is under the control of measurements which permit sensitive 1988 and spring of 1990, and mixing policy makers, and changes are possible testing of the model at an altitude ratios of SOj measured during the spring of with the appropriate trade-off in economics equivalent to an elevated layer of the 1990 at one high elevation site are and lifestyle. Two gas-phase species of model throughout the long time periods for compared with the predictions of the Acid current concern in the lower troposhere are which the model is expected to have good Deposition and Oxidant Model (ADOM). ozone (03 - an oxidant and greenhouse predictive skill (e.g. seasonal means, etc.). These sites are representative of rural gas) and sulphur dioxide (S02 - the The CHEF high elevation surface sites are areas downwind of major anthropogenic precursor to sulphate which is one of the exposed to higher wind speeds (Bridgman source regions. This is the first evaluation primary causes of the acidity in et al., 1994) and have generally higher of a regional-scale Eulerian transport and precipitation and fog). mixing ratios and smaller diurnal variations chemistry model using data from Canadian in 0 3 than low elevation surface sites. The high elevation sites. Mathematical air-quality models which CHEF mountain sites have long records of The observations show higher average 0 3 incorporate complex chemistry and ozone and meteorological parameters, as mixing ratios in the spring than the meteorology have been developed to well as fog and precipitation data summer at both the more northerly high provide guidance in formulating the most (Schemenauer et al., 1995), which can be elevation site and at the valley site. The appropriate control strategies for air very complementary to data from standard model results for comparable elevations pollutants with regional impacts. The Acid surface networks, aircraft and remote show a different seasonal tendency, with Deposition and Oxidant Model (ADOM), a sensing in further model evaluation. higher average 0 3seen in the summer. In regional-scale Eulerian atmospheric the summer the average modelled ozone transport and chemistry model, was METHOD developed in a cooperative effort funded mixing ratio is about 14 ppbv higher than The Measurements the average measured ozone mixing ratio by the Canadian federal government, the for the more northerly high elevation site, Province of Ontario, the Electric Power The 0 3 mixing ratios were measured at and 8 ppbv higher for the more southerly. Research Institute, and the Federal Roundtop Mountain (RTR, 45°05'17"N, In contrast, the average modelled ozone Republic of Germany to aid in the 72°33’09" W, 845 m-msl), a nearby valley mixing ratio for the spring is 4 to 6 ppbv understanding of the impact of emission site (RTV, 45°04'32"N, 72’40'33"W , 250 lower than the average measured ozone controls on acid deposition and m-msl) and Mont Tremblant (MT, mixing ratio for all three sites. In both ground-level oxidant concentrations 46° 1 2’50" N, 74°33'20" W, 860 m-MSL). seasons the range of the hourly ozone (Venkatram et al., 1988; Karamchandani The S02 measurements were made at mixing ratios observed at the high and Venkatram, 1992). Models such as RTR. These sites are northeast of elevation sites is greater than that ADOM must be carefully evaluated with widespread sources of anthropogenic predicted by the model. The measured and field data so that their performance can be pollution in North America (Benkovitz et modelled sulphur dioxide hourly mixing assessed before the predictions can be al., 1994). Minimal anthropogenic activity ratios, averaged over a five week period, used with confidence. The Eulerian Model is seen to the north of MT, and this site is are both near 1.29 ppbv. In the spring, Evalation Field Study (EMEFS) was carried considered to be representative of the diurnal variations in 03 and S02 are out from June 1988 to May 1990 at background conditions when under the well represented by the model. surface sites in eastern North America to influence of northerly air. gather data for the evaluation of ADOM The ability of the model to predict days and the Regional Acid Deposition Model, Ozone was detected with TECO 49 u.v. with the upper or lower quartile of 03 which was developed for use in the U.S.A. photometric analyzers equipped with mixing ratios is assessed using the True (e.g., Byun and Dennis, 1995). From July automatic pressure and temperature Skill Statistic (TSS), with the highest skill 15 through August 31, 1988 and March compensation, and calibrated with sources (TSS= .77) shown for low 0 3 events in the 15 through April 30, 1990, enhanced traceable to NIST transfer standards. summer at the high elevation sites and the observations, including aircraft Sulphur dioxide was monitored with a lowest skill (TSS = .27) shown for the measurements of 0 3 and S02 mixing ratios TECO 43A pulsed fluorescence analyzer valley site for both high and low 03 at altitudes from 0.5 to 5 km, were made which was calibrated with a permeation episodes in the spring. The upper quartile in central Ontario to support the model tube dilution system. The sample inlets 0 3 events at both high elevation sites are evaluation. Evaluations of the performance were located 3 m above ground level. The predicted with a TSS of 0.56 or greater for of ADOM during the summer period have signals from the 03 and S02 analyzers both seasons. The model shows poor skill been made with aircraft data (Macdonald were sampled every 5 seconds and at predicting the daily trends in S02. et al., 1993) and with 0 3 profiles to 1 5 km recorded on a data logger as 15-minute obtained with ozonesondes and differential averages. For this analysis, hourly It is recommended that the sensitivity of absorption lidar (Hoff et al., 1995). averages were derived for both species. the model output to the choice of Due to routine zeroing of the S02 analyzer boundary conditions for 03, the mixing Observations of meteorological parameters for 30 minutes within each even hour processes in the lower 1 km of the and ozone mixing ratios have been made at (UTC) hourly averages are available for odd atmosphere during the summer season, high elevation rural sites in forested areas hours only. The detection limit for S02 is and the loss of 03 in the nocturnal of Quebec since 1986 as part of the estimated at 0.1 parts per billion by inversion in summer be further investigated Chem istry of High Elevation Fog (CHEF) volume (ppbv) and the hourly 0 3 mixing since these processes appear to program (Schemenauer, 1986), with ratio is known to 1 ppbv. For the time significantly influence the ADOM sulphur dioxide monitored at one site from periods considered, the CHEF data predictions of ozone mixing ratio. Sept. 1989 through July 1990. In this recovery is 100% for 0 3 and S02, except paper, data from these sites, located 300 for the summer of 1988 when 03 INTRODUCTION to 500 km east of the aircraft study, are measurements are available only 90% of compared with the results of ADOM for the tim e at RTR and 98% of the tim e at One current problem in atmospheric RTV. In this evaluation, model results are science is understanding the complex the two EMEFS enhanced observation periods. Whereas the aircraft observations not included for periods of missing

72 Physics in Canada March/April 1996 observations. The effect of the exclusion m-agl. MT is located near the centre of hourly mixing ratios seen in the summer of one-half the modelled results for S02 grid square 19,20. Approximately 200 km (Figure 1) and spring (Figure 2) intensive was investigated. The daily averages of to the southeast, the RTR and RTV sites periods. Whereas in the spring period the S02 mixing ratio were calculated with are centrally located on the north-south measured 03 mixing ratios approach a results for all hours and then again with border of grid squares 20,19 and 21,19. normal distribution at all sites, with a the odd hours only. The two sets of Data from MT were compared with model well-defined peak at 45 to 50 ppbv for the values were correlated with an r2 predictions for grid square 19,20 (MT-M5, high elevation sites and at 35 to 40 ppbv exceeding 0.999 and with mean, median MT-M6) and model results for grid squares for RTV, the distributions for the summer and maximum differences of 0.02, 0.01 20 ,19 and 21,19 were averaged (RT-M1, period are substantially broadened and and 0.1 ppbv, respectively. RT-M5, RT-M6) to be compared with the skewed to lower 0 3 mixing ratios, peaking data from the Roundtop sites. It will be at 20 to 25 ppbv at MT, 30 to 35 ppbv at The locations of the high elevation sites shown that the model predictions for RTR, and 10 to 25 ppbv at RTV. The were chosen to provide exposure to the layers 5 and 6 are similar, and in general number of hours in which the mixing ratio prevailing wind directions, and to be will not be distinguished from each other in of ozone exceeded the 1 hour Canadian relatively elevated and isolated compared the figures. Ambient Air Quality Objective of 82 ppbv with the surrounding terrain. These sites is small for all sites. The highest 0 3 mixing are regularly impacted by low level stratus A second approach to the evaluation of the ratios are seen at MT in the summer with 4 and cumulus, and it is clear from the model, which considers both RTV and RTR hours of data reaching 90 to 128 ppbv. motion of these cloud fields that the sites to be surface sites in the layer M l, will be Contrary to the observations, the model are under the influence of air driven by discussed. In this case these two sites results, also shown in Figures 1 and 2, are synoptic winds characteristic of elevated represent the topographic extremes for skewed toward higher 0 3 mixing ratios in altitudes. Upslope and downslope winds sites located within the grid square, and the summer period, and do not reproduce are important only under the condition of the observations are bounds for conditions the lower 03 mixing ratios seen at that very low synoptic winds. The amount of in this layer. time. For both periods, the modelled orographic lift is small compared with the distributions for the high elevation sites mixing in the boundary layer, and the high The hourly-averaged observations were appear to be composites of two elevation sites will be located within the compared with the model predictions both distributions, one tending to follow the mixed boundary layer during most as frequency distributions and as scatter- observations, and the second providing a afternoon periods. plots. Diurnal variability was established by peak at low 0 3 mixing ratios in the spring averaging the observations or model results and at high 0 3 mixing ratios in the summer. The Model and Data Analysis for each of the 24 hours in the day over the The closest agreement for the distributions The model domain consists of 33x33 grid entire summer or spring study period. is seen between RTV and RT-M1 for the squares, each approximately 127x127 spring season, with the model results close km2, covering eastern Canada and the The ability of the model to predict days to normal, but slightly skewed to lower United States, with 12 layers in the with high or low 0 3 mixing ratios was mixing ratios. The model predictions are vertical spanning 1 to 10,000 m-agl. A assessed with the True Skill Statistic (TSS) more narrowly distributed than the grid cell refers to the volume occupied by (Flueck, 1987) as follows. To allow the observations in the summer for all sites, one layer in one grid square. The output time trends to be evaluated independently and do not reproduce the tail at higher 0 3 consists of hourly averages of a wide of the absolute mixing ratios seen, mixing ratios seen at the high elevation variety of chemical species, including 0 3 daily-averaged predictions for each of sites in the spring. MT-M5, RT-M5 and RT-M1, and data from and SO?, which represent the volume 300 - average for the grid cell. The version of MT, RTR and RTV were ranked and tagged the model under evaluation is ADOM 2Bi as in the upper or lower quartile for each (Macdonald et al., 1993), which was run set (i.e. the two ranking schemes: top for both EMEFS intensive time periods 25% or remaining 75%; bottom 25% or using the observed meteorology. Model remaining 75%). Since, as will be seen, results for July 15 to August 31, 1988 model layers 5 and 6 see the same time and March 25 to April 30, 1990 are used series of events, the observations and for the comparison. model predictions were related as MT with M T-M 5, RTR w ith RT-M5 and RTV w ith The model uses a single ground height RT-M1. In addition, to directly compare representative of the average topography the skill of the model w ith the regionality of in the grid square. For the grid squares the ozone events, observations of 0 3 considered here the ground height used for mixing ratio from RTR were used to the model is 416 m-msl near MT and "predict" conditions at MTR and RTV. The approxim ately 47 0 m-msl near RTR and linkage between the model predictions for RTV. In southern Quebec the actual the grid squares of interest was topography within a grid square is investigated by applying the TSS to results complex, (e.g. the sites RTR and RTV are from MT-M5 and RT-M5. The TSS is separated by about 10 km in the based both on correct predictions (hits -e.g. horizontal, and 600 m in the vertical) and both the model predicts and the the correct application of the observations observations show a day in the top 25%) to model evaluation is open to some and false predictions (misses - e.g. the interpretation. Two scenarios are model predicts an upper quartile day but considered here. A comparison is made the observations do not show this to be considering RTV to be representative of true). Values of the TSS of 1, 0, and -1 Fig. 1 Frequency distributions for the hourly the lowest layer of the model and RTR and indicate perfect predictive capability, no predictive skill, and the wrong forecast ozone mixing ratios which were MT to be representative of conditions near measured (solid bars) and modelled 600 m-agl. This approach is favoured by every time, respectively. Incorrectly (hatched bars) for July 15 to the authors. predicting 10%, 40% and 50% of the time August 31,1988. Values for M5 and can give TSS values near 0.8, 0.2 and 0, M6 are shown for MT and RTR. respectively. The CHEF data from the mountaintop sites Since ADOM gives an average over a grid were compared with layers five and six of cell it can be expected to be less variable the model (hereafter M5 and M6), which RESULTS AND DISCUSSION than measurements made at a particular span 416 to 646 and 646 to 1000 m-agl Ozone site. This may explain the inability of the respectively. Data from the valley site model to capture tails of the distributions were compared with layer one of the There is a marked difference in the adequately. However it is clear that the model (Ml), which represents 1 to 56.2 frequency distributions of the measured 0 3 model has consistentdifficulty, overdistance

La Physique au Canada mars à avril 1996 73 scales of 200 km and a range of altitudes, in species. If the MT measurements in the compared with a predicted 10.6 ppbv. predicting 0 3 mixing ratios greater than 70 spring (shown in Figure 2a) are assumed to Since the minima at the high elevation ppbv for both seasons. be normally distributed, then the estimated sites do not occur at night it is clear that error in that average is 0.3 ppbv. these sites are not under the influence of the nocturnal inversion in the same way as T A B L E 1 RTV, but instead are under the influence of Average O- mixing ratios (ppbv) for the summer 1 988 and spring 1990 periods. The standard deviation is shown in tropospheric air continually transported to b ra c k e ts . the site. It is possible that the diurnal n u m b e r o b s e rv e d ------modelled zone- — minimum observed at MT and RTR is due o f h o u rs zo n e M 5 M 6 M l to Oa-depleted air from below the nocturnal s u m m e r inversion mixing up from the surface in M T 1 1 4 7 3 5 (1Θ ) 4 8 (1 1 ) 5 0 (1 0 ) RTR 1 0 3 2 4 3 (1 6 ) 5 0 (1 0 ) 5 2 (1 0 ) response to surface heating. This - ;i R T V 1 1 2 4 2 8 (1 7 ) 3 2 (1 2 ) mechanism would lead to a larger o|. s p rin g amplitude in the summer, as observed at M T 8 8 8 4 3 (9) 3 7 (9) 3 9 (9) R TR 8 8 8 4 4 (1 0 ) 3 9 (8) 4 1 (9) all sites, because deposition to the R T V 8 8 8 3 6 (9) 3 2 (9) _«iL .[ iilm...... vegetation at the surface is stronger during • » M 7» tOO the nocturnal inversion in the summer than The data in Table 1 show that the largest to the snow covered surface in the spring. measured seasonal difference in average This is consistent with RTV, which shows 0 3 mixing ratio was seen at RTV and MT, the strongest afternoon peak and the with 8 ppbv more Oa seen in the spring sharpest decline at night, being below the period; a small difference of 1 ppbv was nocturnal inversion while RTR and MT are seen at RTR. Consistent with earlier above. This diurnal behavior of the high observations (Schemenauer and Anlauf, elevation sites supports the use of data 1987) a positive gradient is seen with from these sites to evaluate the model in Fig. 2 Frequency distributions for the hourly elevated layers. ozone mixing ratios which were elevation, and the more northerly MT site measured (solid bars) and modelled tends to have lower summertime 0 3 mixing (hatched bars) for March 25 to April ratios on average than the RTR site. The 30, 1990. Values for M5 and M6 are model overpredicts the average ozone shown for MT and RTR. mixing ratio seen in the summer in M5 and M6 by about 14 ppbv at MT, 8 ppbv at Scatter plots relating the hourly RTR and 4 ppbv at RTV. For the spring observations at RTR with model season the model underpredicts the predictions for RT-M5 are shown in Figure average ozone mixing ratio by about 5 3. Similar trends (not shown) are seen for ppbv at MT and 4 ppbv at RTR and RTV. M6 predictions for RTR and for M5 and M6 No seasonal difference is predicted for the at MT. In the summer the points are generally clustered above the 1:1 line, average 03 mixing ratio for RTV. The model does show a positive gradient with showing model overprediction. In the elevation, and lower mixing ratios at MT. spring the points fall generally below the 1:1 line, showing model underprediction. The mean diurnal variation in 0 3 mixing The relationships are not linear, but curve ratio for the measurements and model at higher 0 3 mixing ratios, with the model results is shown in Figure 4. The model predicting lower hourly mixing ratios than overprediction in the summer period and observed for both time periods. underprediction in the spring period can be seen to be quite uniform throughout the Summer SP™9 day at the high elevation sites. The summer data at RTV show good agreement with the model predictions in the late afternoon. The observed ozone mixing ratios for the high altitude sites show the maxima for the diurnal cycle occurring near 2 UTC and 21 to 23 UTC Fig. 4 Diurnally averaged 03 mixing ratio for for the summer and spring periods, MT (top panel), RTR (middle panel) and respectively, and the minima occurring RTV (lower panel). Local Eastern near 14 UTC and 15 to 19 UTC in the Standard time is given by UTC - 5 hours. summer and spring periods, respectively. The amplitude of the diurnal variation at The lateral boundary conditions for the model (Michael Moran, personal Fig. 3 Measured and modelled hourly 0 3 MT is 9.7 and 4.8 ppbv in the summer and mixing ratios for RTR and RT-M5 for spring periods, respectively. The communication) for the summer period for the summer and spring intensive amplitudes seen at RTR are about half a 0 3 were mixing ratios of 41.9, 60.2 and periods. The 1:1 line is shown for ppbv smaller. The predicted M5 and M6 61.9 ppbv for layers 1, 5 and 6, each plot. ozone mixing ratios for the high altitude respectively, along the western grid boundary and 31.2, 32.8 and 33.7 ppbv The measured and modelled average hourly sites show the diurnal cycle occurring with for layers 1, 5 and 6, respectively, for the 0 3 mixing ratios for the summer and spring approximately the same timing, but with northern and eastern boundaries, and most intensive periods for the three sites are smaller amplitude in the summer of the southern boundary. Three grid given in Table 1. Values calculated in the (approximately 2 ppbv) and at MT in the squares in the southern boundary, those same manner as standard deviations are spring (2.4 ppbv). The timing of the shown for each average, even though observed and predicted diurnal variation at over Florida, were given the same conditions as the western boundary. The some of the distributions are far from RTV agrees well, with the maxima near 18 lateral boundary conditions for the spring normal (Figures 1 and 2). The large range UTC and 21 UTC in the summer and spring seen in the data does not indicate an periods, respectively, and the minima near period were 0 ;) mixing ratios of 44.9, 44.1 inability to determine the average precisely 10 UTC. The amplitude of the signal at and 45.3 ppbv for layers 1, 5 and 6, due to some random error, but rather RTV is measured to be 21.6 ppbv in the respectively, along the boundaries in the southwestern corner and 30.1, 31.6 and shows the wide range of mixing ratios summer period, compared with a predicted actually seen due to the effects of value of 16.4 ppbv. The agreement is 32.5 ppbv for layers 1, 5 and 6, different meteorology on the chemical better in the spring period, with a respectively, for the northwestern, processing and transport of the pollutant measured amplitude of 11.8 ppbv northern, eastern and southeastern

74 Physics in Canada March/April 1996 boundaries. Figures 1 and 2 show that the predicted values lie at lower mixing ratios predicted distribution for the first layer. predicted model mixing ratios in layers 5 than the observations. Higher variability, The summer average mixing ratio in the and 6 have a peak within the range defined on a daily averaged basis, is seen for 0 3 in lowest layer could be reproduced by a by the boundary conditions for each the summer period than in the spring suitable averaging of the RTV and RTR season. This comparison suggests that period. The TSS test of time trends of data, but any such averaging for the spring for much of the time the ozone modelled measured values and model predictions for season w o u ld still lead to an for M5 and M6 at these locations simply all sites is shown in Table 2. The model underprediction. reflects transport and mixing of the ozone shows its highest success (TSS which was input as a boundary condition approximately 0.77) in predicting periods at that layer. If this is indeed the case with low ozone mixing ratio at both RTR then the observations indicate that lower and MT in the summer, with the next input concentrations should be specified in highest success (TSS of 0.67) for low the summer season, and higher in the ozone periods at RTV in the summer. The spring than currently in use, and the upper quartile days are predicted with a sensitivity of the model results to the TSS of at least 0.56 for MT and RTR over choice of boundary conditions should be both periods. The poorest performance is investigated. seen for RTV in the spring.

Another factor which could contribute to The TSS indicates that the model the overprediction of 0-, mixing ratios in demonstrates a strong regionality in ozone th e summer period is model episodes in layer 5, with a TSS > 0.8 for (b| underestimation of the 0 3 destruction at both seasons for low ozone and a TSS night at low elevations. Unfortunately it near 0.7 for high ozone with results for is not clear if the difference seen at night RT-M5 used to predict MT-M5. The TSS between the average measured and supports the use of data from MT and RTR modelled mixing ratios in the summer in as representative of regional scale ozone layer 1 is due to the model underestimating episodes since RTR can "predict" the the losses in the nocturnal boundary layer conditions at MT on a large fraction of or to the limited vertical resolution of the days (TSS range between 0.56 and 0.76). model (Byun and Dennis, 1995). In These applications of the TSS give a addition, the weak mixing in the lower standard by which to judge the layers of the model as suggested by performance of the model for the high comparison of the diurnal variation at elevation sites. In general the model can higher layers, would contribute to the predict the timing of periods with high and transport of 0 3 mixing ratios characteristic low ozone as observed at the high of the initial boundary conditions. elevation sites over distances of 200 km. The interpretation of the TSS for daily averages at RTR and RTV is com plicated ■0 by the fact that the valley site is subject to MT the stronger diurnal variation.

T A B L E 2 True Skill Statistic calculated on 48 days of data for MT and 40 RTV, and 44 days of data for RTR in the summer and 37 days of data for all sites in the spring for the lower (L) and upper (H) quartiles of data.

S u m m e r L S u m m e r H S p rin g L S p rin g H

R T -M 5 to p re d ic t 0 .7 6 0 .6 4 0 .5 6 0 .5 6 RTR

M T M 5 to p re d ic t 0 .7 8 0 .5 6 0 .4 1 0 .5 6 WT

R T -M 1 to predict 0 .6 7 0 .4 4 0 .2 7 0 .2 7 RTV

RTR to p r e d ic t 0 .7 6 0 .6 4 0 .5 6 0 .7 1 NT

RTR t o p r e d ic t 0 . 5 2 0 .7 6 0 .5 6 0 .2 7 RTV

R T -M 5 Fig. 5 Ozone data for the summer intensive to predict 0.89 0.67 0.8S 0.71 period showing measured (solid M T -M 5 Fig. 6 Observations and model results for SO? symbol, solid line) and modelled (open mixing ratios at RTR during the spring symbol, dashed line) daily averages. period: a) frequency distribution of Both M5 and M6 are shown for for measured (solid) and modelled (hatched) MT and RTR. If RTR and RTV are both considered as hourly data. b| scatter plot of hourly sites in M1 the following conclusions data with RT-M5 results, c) time series Time series of the measured and modelled of measured hourly averages (dashed daily averages of O, mixing ratio are reached above will still be valid. Any line), measured daily averages (solid combination of the distributions observed shown in Figure 5 for the summer symbol/line), and modelled daily averages during the summer period at RTR and RTV (open symbol/line) and d) diurnally intensive period. The regional nature of will lead to a distribution that indicates averaged measurements (solid symbols) the ozone events can be seen by and model results (open symbols). The comparing the measured curves from the more hours with 0 3 mixing ratio above 60 results for both RT-M5 and RT-M6 are ppbv than does the predicted distribution different sites. The trends with time for shown for all plots except b) which RT-M1. Any combination of the shows RT-M5 only. the measured and predicted daily-averaged distributions observed at these sites in the ozone mixing ratios for the spring period spring will lead to a distribution which Sulphur Dioxide (not shown) are similar to those shown in peaks at higher 0 3 mixing ratios than the Figure 5 with the exception that the The distribution of measured S02 mixing

La Physique au Canada mars à avril 1996 75 ratios in the spring period is skewed, with have reported for high elevation sites, e.g., observed values in both seasons, and the mode in the range 0 to 0.5 ppbv, over Lefohn et al. (1990) for Whiteface which give higher mixing ratios on average half the data within 1 ppbv of zero, and Mountain and Aneja et al. (1994) for two in the summer than in the spring. Thus the maximum values reaching 8 ppbv (Figure elevations (2006 and 1760 m-msl) in North seasonal dependence of the 0 3 mixing ratio 6a). The small negative values are due to Carolina. Aneja and Li (1992) report the is different for the model and the variability in the zero correction. The August 1988 Whiteface Mountain mean observations. This difference may be distribution for the ADOM predictions, also ozone concentration to be 50.3 ppbv. This related to the choice of boundary shown in Figure 6a, is a good is similar to, but higher than, the value conditions, and to underestimation of the representation of the measurements. given for the ADOM period for the CHEF depletion of 0 3 near the surface at night in However, an hour by hour comparison of RTR site in Table 1 (43 ppbv). Whiteface the summer. the observations and M5 results (Figure M ountain is 140 km southw est of RTR and 6b) shows considerable scatter. Results at an elevation 630 m higher. In general, The ADOM mixing ratios for both the for M6 are similar. where comparisons can be made, and summer and spring time periods very rarely considering the general south to north exceed 60 ppbv and are never greater than The time series of daily averages of decrease in ozone concentrations in 70 ppbv whereas the measurements reach measured and modelled S02 mixing ratio eastern North America, the measured and exceed 90 ppbv at times. Thus the (Figure 6c) shows periods with very good ozone concentrations at the two CHEF model cannot reproduce the magnitude of agreement, as well as periods with mountain sites seem representative of events with high 0 3 mixing ratio. overprediction and underprediction. The values to be expected at 850 m-msl and TSS indicates poor predictive capability for should provide a good basis for comparison The prediction of the timing of events is the model with values of 0.27 for the upper with the ADOM model. often evaluated simply by visual quart ile days and 0 .1 2 for the low er quart ile inspection, which tends to fix the eye on days. Comparison of Model Evaluations the major peaks in the time series, The results for the summer period given especially if agreement is found between The average S02 mixing ratios over the above agree well with conclusions drawn the observations and predictions for these five week period were 1.29, 1.29 and for model intercomparisons for the same peaks. The application of an objective 1.25 ppbv for the measured, M5 and M6 time period for southern Ontario. numerical measure of agreement, such as values respectively, showing excellent Macdonald et al. (1993) concluded that the True Skill Statistic, is recommended. agreement. The diurnal variation in S02 the model can predict the timing of For the times investigated here, it is shown mixing ratio (Figure 6d) has an amplitude episodes in the lower troposphere (250 to that the model has the greatest skill in of 0.5 ppbv, and a maximum near 14 UTC 2200 m-agl), that the full range of predicting the timing of low ozone periods in both the model results and observed 0 3 mixing ratios was not seen by at the high elevation sites. measurments, indicating that on average in the model, and that the observed vertical the spring season S02, as 03, is mixing of pollutants was underpredicted by The measured and modelled diurnal appropriately mixed through the lower the model. Hoff et al. (1995) concluded variations in 0 3 are similar in the timing of troposphere. that ADOM treats the temporal behaviour the maxima and minima, indicating that the of 0 3 fairly well in the lower troposphere mixing in the boundary layer is occurring at The above observations indicate that the but not near the surface, that the model the right time of day, and depletion of emission of the primary pollutant S02 and performs best during simple synoptic ozone is occurring in the nocturnal its subsequent transport to southern conditions with a relatively clean inversion. However the difference Quebec are well represented by ADOM over atmosphere, and that local chemistry between the maxima and minima in the the full spring period. However, the appears to be secondary to larger-scale predicted values are lower than in the predicted timing of episodes of high S02 is dynamic motions through the free observed values for the summer period for poor both on an hourly and daily basis. This troposphere in controlling the average both high elevation sites and in the spring is not surprising since, unlike 0 3 which is ozone concentration. The data and gradually produced from a complex mix of at MT, indicating that the model treatment method used for the evaluation given in pollutants in the lower troposphere, S02 is of boundary layer mixing may not be this paper permit more sensitive and introduced into the atmosphere at elevated strong enough. This would be especially quantitative testing of the model in layers levels from a variety of point sources to the evident in summer when increased surface 5 and 6, and will be appropriate for south and west of the sites. Small shifts in losses are seen in the nocturnal boundary evaluating the effect of proposed changes wind direction or changes in vertical layer. Mixing to higher layers is important to the model. stability of the atmosphere relative to the since it affects not only the concentrations model resolution can cause the plumes to at that layer, but the long range transport CONCLUSIONS hit or miss the grid cells being evaluated. of species due to the higher wind speeds There is no observational evidence The application of the True Skill Statistic aloft. presented here to indicate that the S02 to the ozone measurements at the high episodes seen at RTR on an hourly or daily elevation sites confirms that periods of The mixing ratios of S02 at RTR during the basis are routinely representative, on these high and low ozone mixing ratio occur over spring period range from near zero to time scales, of conditions over the entire distance scales of 200 km in southern approximately 10 ppbv in well-defined grid cell. Quebec. Comparison of the ozone data events. The distribution of hourly S02 from the Canadian sites with results from mixing ratios for the model results and Additional High Elevation Ozone other mountain observations in eastern measurements agree well, but the model Measurements North America show decreasing ozone shows poor skill in predicting the timing of concentrations with increasing latitude. episodes. The diurnal variation in S02 is The results from the CHEF sites can be These long term measurement programs well represented by the model, consistent compared with results of ozone can supply valuable continuous with the good agreement seen for 0 3 at measurements at high elevation sites in the measurements for the evaluation of air RTR for this time period. eastern U.S. Aneja and Li (1992) show chemistry models. diurnal variations at Whiteface Mountain, ACKNOWLEDGEMENTS N.Y. (1483 m-msl) and Mt. Moosilauke, The distributions of 03 mixing ratios N.H. (1000 m-msl). In the summer of We thank Francine Juillet, Louis Veilleux, observed for the summer 1988 and spring 1988 (May to October) both sites show Alaine Dufresne, Sylvain Savoie and 1990 EMEFS intensive periods are minima from about 0900 to 1200 local Nicolas Durand for operating the CHEF different, with a smaller range of values time and broad maxima extending from sites, and Sheldon Opps for assistance in seen in the spring than in the summer and about 1800 to 2400. This is very similar data processing. with higher average 0 3 mixing ratio seen in to the diurnal patterns shown in Figure 4 for the two CHEF mountain sites during the spring than in the summer. The ADOM the ADOM period. These diurnal patterns predicts distributions of 0 3 mixing ratios are consistent with what other authors which span a smaller range than the (continued on page 80)

76 Physics in Canada March/April 1996 CONTRÔLE DES MODES LATÉRAUX DE LASERS À SEMI CONDUCTEURS: EXPÉRIENCES ET SIMULATIONS

par Nathalie McCarthy, Sylvain Mailhot, Damien Stryckman, Yves Champagne* et Guy Rousseau Équipe Laser et Optique Guidée, Centre d'Optique, Photonique et Laser (COPL), Département de physique. Université Laval, Québec, G1K 7P4, Canada, Tél.: (418) 656-3120, Fax: (418) 656-2623, e-mail: [email protected] * Gentec Inc. 2625 Dalton, Sainte-Foy, Québec, GIP 3S9, Canada

Résumé ont une faible discrimination entre les termine la cavité. La fabrication de ces modes latéraux et tendent à émettre couches anti-réfléchissantes est décrite Les lasers à semi-conducteurs de simultanément sur plusieurs modes. La puissance élevée, à large fenêtre plus loin dans cette section. La lentille f, présence de ces modes d'ordre supérieur d'émission, sont devenus des sources collimate le faisceau qui est ensuite est à l'origine d'une forte dégradation de la focalisé par la lentille F sur la fente cohérentes très compétitives pour cohérence spatiale du faisceau et d'une d'entrée d'un spectromètre à réseau plusieurs applications. Cependant, ces distribution d'intensité en champ lointain (Jarrell-Ash, résolution = 0.01 nm) à la lasers émettent simultanément sur qui s'élargit rapidement lorsque le courant sortie duquel une caméra CCD plusieurs modes latéraux, ce qui augmente d’injection augmente. Ces comportements monochrome (Spiricon) enregistre l'image la divergence du faisceau et en diminue la sont très néfastes lorsqu'on veut, par du champ proche du faisceau résolu en cohérence spatiale. Notre but consiste à exemple, utiliser le faisceau pour pomper longueur d'onde. Le laser a été positionné réduire le nombre de modes latéraux optiquement un autre laser; le faisceau doit de façon à ce que la jonction (et par contenus dans le faisceau émis par ce type plutôt être focalisable sur une petite tache conséquent l'axe latéral) soit de lasers disponibles commercialement. tout en restant étroit sur une grande perpendiculaire au plan de la figure 1. Pour Quelques techniques de contrôle de modes distance le long de l'axe de propagation z, travailler dans des conditions de cavité latéraux ont été proposées et testées avec cette distance étant optimale lorsque le externe anamorphique, nous ajoutons une des lasers de 100 mW: cavités externes faisceau ne contient que le mode latéral lentille cylindrique f2 (de 25 mm de focale) terminées par différents composants gaussien. entre f, et M,; cette nouvelle lentille optiques et couches à réflectivité profilée n'ayant un effet que le long de l'axe latéral déposées directement sur la face de sortie Dans cet article, nous présentons x. des lasers. Nous présentons aussi les différentes méthodes que nous avons résultats de simulations numériques reliées utilisées pour réduire le nombre de modes Afin d'alléger l'écriture, nous désignerons aux expériences réalisées. latéraux dans les diodes laser BA tout en par la lettre A la configuration pour laquelle conservant une puissance relativement la lentille f2 et le miroir M, sont absents du Abstract élevée: les cavités externes montage. Dans ce cas, nous avons fait les High power broad-area (BA) semiconductor anamorphiques, les cavités à symétrie mesures avant de déposer une couche AR lasers are now considered as interesting cylindrique terminées par différents sur la face de sortie du laser. La sources of coherent radiation for various composants optiques (miroir uniforme, configuration B sera celle qui comporte une applications. However these lasers emit miroir à réflectivité profilée...) et les cavité externe anamorphique1'". Dans ce simultaneously on several lateral modes, couches à réflectivité profilée déposées cas, M, est un miroir plan à réflectivité which contribute to increase the beam directement sur la face de sortie (face uniforme (R = 30 %), la distance L, entre divergence and to decrease the spatial d'émission) des diodes laser. Les le laser et la lentille f, est de 8 mm et f, coherence of the emitted laser beam. Our techniques de déposition sont brièvement possède une focale de 8 mm. La distance goal consists in reducing the number of décrites. Les résultats de simulations L2 entre M, et la lentille cylindrique f2 peut lateral modes contained in the beam numériques reliées aux travaux être variée alors que la distance d entre f, emitted by commercially available BA expérimentaux sont aussi présentés. et f2 est gardée fixe à 30 mm. Le grand lasers. Some techniques of lateral mode intérêt de cette configuration réside dans le control have been proposed and tested CAVITÉS EXTERNES fait que la taille de la distribution with a 100 mW BA laser: external cavities transverse d'intensité (dans la direction y) Les cavités externes (ou cavités étendues) terminated by various optical components du faisceau à la face de sortie du laser est ont déjà fait leurs preuves pour le contrôle and profiled reflectivity coatings deposited la même après son trajet dans la cavité des modes latéraux."31 Les cavités directly on the output facet of the lasers. externe. Ceci permet d'optimiser le externes offrent plusieurs degrés de liberté Numerical simulations of the lateral mode couplage transverse entre le faisceau et le puisqu’on peut varier le nombre et le type discrimination of these configurations are guide d'onde du laser. Dans la direction de composants intracavités, de même que also reported. latérale (direction x), on recherche le type de coupleur externe. La figure 1 exactement le comportement inverse: le montre le schéma du montage que nous INTRODUCTION faisceau qui revient dans le laser s'est avons utilisé pour mesurer les principales élargi pendant son trajet dans la cavité caractéristiques d'émission de la diode Les lasers à semi-conducteurs (ou diodes externe et c'est le milieu de gain lui-même laser en cavité externe. laser) de puissance élevée ont atteint des qui agit comme filtre spatial profilé, niveaux de performance qui en font des favorisant ainsi la présence des modes sources cohérentes compétitives pour une latéraux les plus étroits. Finalement, la vaste gamme d'applications: mémoires configuration C ne comprend que la lentille optiques, génération d'harmoniques, de collimation f, et un miroir M, dont la systèmes de communication optique et réflectivité varie de façon gaussienne avec pompage optique de lasers à l'état solide. le rayon161 La forme exacte du profil de On divise habituellement les diodes laser réflectivité est donnée par de puissance en deux grandes catégories, soient les réseaux monolithiques de diodes R(p) = 0.6 2 exp[-(p / w j ?| , laser et les lasers à large ruban d'injection ("broad-area" ou BA). De façon générale, Figure 1. Schéma du montage expérimental de où p est la position radiale et w m (la les réseaux de diodes laser présentent une la diode laser en cavité externe et de l'arrangement utilisé pour l'analyse de demi-largeur à 1 le) est égale à 700 Le bonne discrimination envers les modes son faisceau. profil de réflectivité est obtenu en latéraux (suivant l'axe x, dans le plan de la déposant des couches profilées de jonction) d'ordre supérieur, mais leur mode La face arrière du laser a une réflectivité diélectriques sur un substrat de verre. Il a fondamental se caractérise par un élevée (R ~ 100%). L'autre face (face été réalisé par l'Institut national d'optique déphasage de 180° entre les émetteurs avant) a été recouverte d'une couche (Québec). adjacents, ce qui produit une distribution anti-réfléchissante (AR) afin que angulaire d’intensité à deux lobes dans le l'oscillation laser puisse s'établir entre la Dans toutes les configurations, les lasers à champ lointain. D'autre part, les lasers BA face arrière et le miroir externe Ml qui semi-conducteurs utilisés sont des lasers

La Physique au Canada mars à avril 1996 77 EG&G de GaAs/GaAIAs (modèle identifiés par leur longueur d'onde plus accord avec les simulations numériques; C86090E), à double hétérostructure, avec courte et leur distribution spatiale les croix sur la figure 3 correspondent aux une largeur de ruban de 75 //m et une d'intensité à plusieurs lobes. On peut courants de seuil calculés pour le mode 1. longueur de 37 0 μητι. Ils ém ettent un constater aussi que le mode latéral faisceau de puissance maximale de l'ordre fondamental (à un seul lobe) est beaucoup DÉPÔTS PROFILÉS de 100 mW, à une longueur d'onde de 840 plus étroit sur la face de sortie que les Les configurations B et C augmentent la nm et leur courant de seuil se situe entre modes latéraux supérieurs. La figure 2a a discrimination envers les modes latéraux 220 et 250 mA avant le traitement été enregistrée à une puissance de 32 mW. d'ordre supérieur parce qu'elles limitent anti-réfléchissant. Le faible confinement Pour ce laser, on constate que sept modes latéralement le faisceau lumineux. Le latéral du faisceau lumineux se propageant latéraux étaient présents à cette puissance. meme phénomène peut se produire si on dans le matériau semi-conducteur est La figure 2b a été obtenue avec la cavité élimine la cavité externe et si le profil de assuré uniquement par un mécanisme de externe anamorphique pour laquelle L2 réflectivité est réalisé directement sur la "guidage par le gain". L'émission de telles était de 100 mm. On constate que face de sortie de la diode laser161. Cette diodes laser contient habituellement l’émission est à la fois monomode latérale approche a déjà été testée avec succès plusieurs modes latéraux, meme à des et monomode longitudinale (résultat avec d'autres types de lasers176’. Nous puissances très faibles (de l'ordre du confirmé par d'autres mesures; aucun avons proposé et testé dans notre milliwatt). Par exemple, nous avons battement de mode n'a été observé) à une laboratoire une technique simple pour détecté, avec un de nos lasers, la puissance de 40 mW. Ceci représente réaliser une couche diélectrique mince présence de 3 modes latéraux à 2.5 mW et notre meilleur résultat jusqu'à présent. La profilée sur nos diodes laser. La couche a de 1 1 modes latéraux à 80 mW de figure 2c montre le spectre obtenu avec un une épaisseur qui varie dans la direction puissance émise. Sur les lasers destinés à miroir gaussien externe pour une puissance latérale (parallèle à la jonction) et une être utilisés en cavité externe, nous de 47 mW. L'écart entre les groupes de épaisseur constante dans la direction déposons une couche anti-réfléchissante modes longitudinaux est encore de 0.2 nm. transverse (perpendiculaire à la jonction); sur la face de sortie par évaporation Dans ce cas, on observe un phénomène elle produit donc une réflectivité profilée therm ique. Dans le systèm e à vide, le particulier: le contenu en modes latéraux à dans la direction latérale. Le diélectrique faisceau émis par la diode laser est détecté l'intérieur des groupes associés à des utilisé est du SiO dont l'indice de réfraction pendant que le dépôt de SiO s'effectue; modes longitudinaux différents n'est pas le s’élève à 1.9. l'évaporation est arretée lorsque le signal meme d'un groupe à l'autre. D'une part, il détecté atteint un minimum. Nous aurait été préférable que le profil de Les couches minces profilées peuvent être pouvons estimer que la réflectivité réflectivité ait été plus étroit afin obtenues par deux méthodes similaires. La résiduelle de la face est inférieure à 104 d'augmenter encore plus les pertes des première méthode consiste à placer un après le traitement anti-réfléchissant. modes latéraux supérieurs. D'autre part, la filament très mince à quelques dizaines de réflectivité résiduelle du revêtement AR microns du substrat (voir la fig. 4a). Les figures 2a, 2b et 2c m ontrent les pourrait être à l'origine d'un effet de images du faisceau en champ proche cavités couplées. résolu en longueur d'onde obtenues avec la Cloche de vene diode laser dans les configurations A, B et La configuration qui nous a donné les C respectivement. meilleurs résultats est la cavité externe anamorphique; dans ce cas, le paramètre que nous avons fait varier est la distance L2 entre la lentille f2 et le miroir externe M ,. Les cercles de la figure 3 m ontrent le courant de seuil mesuré expérimentalement de l'ém ission laser (ceci correspond au seuil d'oscillation du mode latéral fondamental, d'ordre 0), alors que les carrés montrent le seuil mesuré du mode d'ordre 1 (ceci correspond donc à la fin du régime monomode latéral). b) Figure 4. Schéma du système à vide contenant le substrat (ou la face d'émission du laser) qui est masqué a) par un filament de diamètre é ou b) par une fente étroite de largeur w.

Le filam ent crée un "e ffe t d'om bre" sur le substrat, produisant ainsi un dépôt c) I d'épaisseur variable. Le temps de » I déposition est ajusté de façon à obtenir r ) une épaisseur égale à λ/4 sur les bords du substrat (λ étant la longueur d’onde du Figure 2. Images du faisceau en champ proche faisceau dans le SiO) et une épaisseur nulle résolu en longueur d'onde pour les L2 (mm) au centre. La pente du profil d'épaisseur configurations A, B et C, pour des est variée en changeant la distance d entre puissances lumineuses semblables. Figure 3. Courants de seuil mesurés des modes le filam ent et le substrat. Les profils de L'axe horizontal représente la latéraux d'ordres 0 (cercles) et 1 réflectivité les plus étroits que nous avons longueur d'onde et l'axe vertical est la (carrés) en fonction de L2 pour la direction latérale x. configuration B. Les croix obtenus (largeur totale à mi-hauteur) ont correspondent aux courants de seuil été réalisés avec un filament de tungstène Cas spectres d'émission présentent une calculés pour le mode 1. de 25 /ym de diamètre placé à environ information très complète. L’axe horizontal 120 μπι du substrat. Cependant, les représente la longueur d'onde, augmentant Les résultats suggèrent que des puissances simulations numériques ont montré qu'un de gauche à droite. L'axe vertical possibles, en régime monomode latéral, profil aussi large n'aurait que peu d'effet représente la position latérale (direction x) puissent être de plus en plus élevées à sur la discrimination des modes latéraux de sur la face de sortie de la diode laser. mesure que la valeur de L2 s'éloigne d'une nos lasers. Trois groupes de modes (chaque groupe plage d'environ 10 mm centrée à 23 mm. correspondant à un mode longitudinal) sont Par exemple, pour L2 = 14 mm, 20 mm et Nous avons plutôt opté pour la seconde montrés dans la figure 2a; ces groupes 60 mm, nous avons mesuré des méthode, qui exploite le meme "effet sont distants en longueur d'onde de puissances monomodes maximales de d'ombre”, mais où le filament est remplacé 0.2 nm. Dans chaque groupe, les modes 21 mW, 10 mW et 40 mW, respective­ par une fente étroite (faite de deux lames latéraux d'ordre supérieur peuvent être ment. Ces résultats sont en excellent de rasoir). Dans ce cas, nous n'avons plus

78 Physics in Canada March/April 1996 de limite inférieure sur la largeur du profil discrimination reste inférieure à 1.1 de réflectivité. Cependant, le dépôt doit seulement pour les valeurs de L2 comprises être réalisé en deux étapes: d'abord une entre 1 5 et 29 mm. Dans cet intervalle, le couche profilée d'épaisseur λ/4 au centre faisceau qui revient dans la diode laser et zéro sur le bord, suivie d'une seconde I I I après son trajet dans la cavité externe est couche d'épaisseur constante (λ/4) du tellem ent étroit q u ’il ne subit pas de même matériau diélectrique. Ceci résulte filtrage spatial dû à la largeur finie du en une couche d'épaisseur λ/2 au centre et Figure 6. Image du faisceau en champ proche milieu de gain. À mesure qu'on s'éloigne λ/4 sur les bords. La figure 5 montre un résolu en longueur d'onde émis par la de cet intervalle, le faisceau de retour exemple de profil d'épaisseur (5a), mesuré diode laser avec le dépôt profilé sur la face de sortie. Axe horizontal: λ et s’élargit et la discrimination augmente. La avec un profilomètre mécanique, et le profil axe vertical: x. figure 2b a été obtenue avec une valeur de de réflectivité calculé correspondant (5b). L2 égale à 100 mm et une bonne Le spectre a été enregistré à une puissance discrimination a effectivement été d'environ 30 mW. On constate que le observée. D'autre part, les croix de la laser avec le dépôt profilé émet seulement figure 3 montre le courant de seuil calculé dans le mode latéral fondamental à cette pour le mode latéral d'ordre 1 en fonction puissance. La puissance maximale qui de la longueur L2 pour la diode laser pouvait être atteinte en régime d'émission opérée dans la configuration B. Ces points monomode latérale était inférieure à 1 mW montrent un bon accord avec les résultats sans le dépôt profilé. expérimentaux obtenus.

SIMULATIONS NUMÉRIQUES Pour la diode laser avec un dépôt profilé (sans cavité externe), nous avons supposé Les logiciels de simulation que nous avons que la réflectivité de la face de sortie était développés ont été utilisés pour le calcul décrite par la fonction 0.3 exp(-x2/wm2), des caractéristiques d'émission des diodes où x est la direction latérale et wm la laser opérées dans les diverses demi-largeur à 1/e du maximum. La position (μηη) configurations présentées dans les figure 7 montre la discrimination |γο|/|γ1 | paragraphes précédents. Ces programmes en fonction de la largeur du profil de utilisent la méthode de propagation de réflectivité, telle que calculée au seuil de faisceaux"0’ pour simuler la propagation du l'émission laser. champ optique dans le laser, un algorithme de transformation d'échelle"" pour la 2.4 - 1------— ' j propagation dans la cavité externe (s'il y a 2.2 I lieu) et l'algorithme de Prony"21 pour § 2 \ extraire les différents modes latéraux (et l 1.8 leur valeur propre associée) pour toutes les configurations. Les logiciels tiennent IΌ 1 - 4 \ compte des variations latérales du gain, de 1 .2 . _ _ _ _ _ l'absorption, des effets thermiques, des 1 ------3 variations latérales de l'indice de réfraction 0 10 20 30 «0 50 -15 10 -5 0 5 10 15 induites par la distribution des porteurs de wm (μιτι) position (pm) charge et de la déplétion de la Figure 7. Discrimination |yoJ/ Jyl | en fonction concentration des porteurs par le champ de la largeur wm du profil de Figure 5. a) Profil de l'épaisseur du dépôt optique due à l'émission stimulée. Nous réflectivité. obtenu avec une fente de 20 pm nous sommes intéressés aux effets de placée à 90 pm du substrat de l'utilisation de cavités externes et de L'amélioration de la discrimination verre et b) profil de réflectivité dépôts profilés sur la discrimination s'accompagne d'une légère hausse du correspondant calculé en considérant un substrat de GaAs. modale, les caractéristiques du mode courant de seuil. L'évolution du courant de latéral fondamental intracavité et celles du seuil en fonction de wm est montrée Ce profil quasi-gaussien a été obtenu en faisceau transmis dans l'air en champ à la figure 8. Par exemple, avec 2w m = plaçant une fente de 20 pm de largeur à proche et en champ lointain. Nous avons 1 5 /vm (largeur du dépôt profilé sur la diode 90 pm du substrat. On constate que la aussi calculé les caractéristiques telles le laser de la section précédente), le courant largeur totale à mi-hauteur du profil de courant de seuil requis pour atteindre le de seuil est 1.25 fois plus élevé que sans réflectivité est d'environ 15 pm, ce qui régime d'émission stimulée et l'efficacité dépôt (passant de 226 à 280 mA), ce qui devrait être suffisamment étroit pour quantique différentielle. correspond très bien aux résultats réduire le contenu en modes latéraux de expérimentaux obtenus (le seuil passant nos lasers. Le principal défi consistait à Les valeurs des paramètres optiques, alors de 220 à 280 mA). centrer latéralement la fente sur la fenêtre électriques et thermiques utilisées dans les émettrice qui n'est pas nécessairement simulations numériques ont été ajustées à 4 0 0 centrée sur la diode laser. Ce problème a celles des lasers EG&G de modèle < été résolu en maximisant la puissance C86090E; celles-ci peuvent être retrouvées £ 350 lumineuse transmise par la fente lorsque le dans les tableaux I et II de la référence 13. laser fonctionne sous le seuil. Nous avons calculé une très faible discrimination envers les modes latéraux Ό Le courant de seuil est passé de 220 mA d'ordre supérieur pour la diode laser sans I 250 O (sans dépôt) à 280 mA avec le dépôt dépôt sur la face de sortie et sans miroir O profilé. Ce comportement était tout à fait externe. En effet, le rapport |γο|/|γ1| 200 —— ---- —— 0 10 20 30 40 50 prévisible puisque la couche profilée entre les valeurs propres des deux modes ¥tm (μπτ) diminue la réflectivité globale de la face de qui ont les plus faibles pertes vaut 1.016, sortie. Toutefois, l'efficacité quantique dans ce cas. Ceci est cohérent avec nos résultats expérimentaux qui montrent que Figure 8. Courant de seuil de l’émission laser en différentielle a été légèrement améliorée, fonction de la largeur du profil de passant de 0.54 W/A à 0.64 W/A. la puissance maximale pour laquelle le laser réflectivité pour une réflectivité sans dépôt émet sur un seul mode latéral centrale de O.3. La figure 6 montre l'image du faisceau en est inférieure au milliwatt. champ proche résolu en longueur d'onde PERSPECTIVES obtenue avec la diode laser ayant un dépôt Pour la configuration B, la discrimination Les techniques décrites dans cet article profilé sur la face de sortie. Iγ° I / 1Ύ1 I a ele calculée pour différentes valeurs de L2. Cette étude a révélé que la offrent plusieurs degrés de liberté pour le

La Physique au Canada mars à avril 1996 79 contrôle des modes latéraux dans les lasers 11. A. E. Siegman, Lasers , Mill Valley: ozone concentrations at a select set à semi-conducteurs à guidage par le gain et University Science Books, pp. of high-elevation sites in the Eastern elles requièrent un équipement 805-81 1 (1986). United States, Environ. Pollut. 67, généralement accessible dans tous les 147-178, 1990. laboratoires d'optique. Les méthodes 1 2. A. E. Siegman and H. Y. Miller, Appl. décrites pour réduire l'oscillation des Opt. 9, 2729 (1970). 10. Macdonald A.M., C.M. Banic, modes latéraux d'ordre supérieur peuvent W.R. Leaitch, K.J. Puckett, être appliquées à des lasers à large ruban 13. Y. Champagne, S. Mailhot and Evaluation of the Eulerian Acid encore plus puissants que ceux dont nous N. McCarthy, IEEE J. Quantum Deposition and Oxidant Model disposions. Les simulations numériques Electron. 31, 795 (1995). (ADOM) with summer 1988 aircraft effectuées se sont avérées en bon accord data. Atmos. Env. 27A, 1019-1034, avec les résultats expérimentaux. 1993. Evaluation of the Acid . . . by C. M. Banic 11. Schemenauer R.S. and K.G. Anlauf, À moyen terme, nous prévoyons utiliser un et al. (continued from pg. 76) Geographic variation of ozone réseau à réflectivité profilée en cavité concentrations at high and low externe pour restreindre le spectre REFERENCES elevation rural sites in Quebec. North American Oxidant Symposium, d'émission à un seul mode longitudinal et 1. Aneja V.P. and Z. Li, Characterization latéral et à en accorder la fréquence. Nous Quebec City, Canada, 25-27 Feb., of ozone at high elevation in the avons mis au point un procédé de 412-429, 1987. Eastern United States: Trends, fabrication de tels réseaux par interférence seasonal variations, and exposure, J. de faisceaux gaussiens sur une photorésine. 12. Schemenauer R.S., C.M. Banic and Geophys. Res. 97, 9873 9888, 1992. Une telle source serait une alternative N. Urquizo, High elevation fog and compacte et peu coûteuse aux lasers precipitation chemistry in Southern 2. Aneja V. P., C. S. Claiborn, Z. Li and présentement utilisés en spectroscopie. Quebec, Canada. Atmos. Env. 29, A. Murthy, Trends, seasonal 2235-2252, 1995. variations, and analysis of REMERCIEMENTS high-elevation surface nitric acid, 13. Venkatram A., P.K. Karamchandani Nous remercions M. Marc D'Auteuil pour ozone, and hydrogen peroxide, Atmos. and P.K. Misra, Testing a son support technique et ses judicieux Env. 28, 1781-1790, 1994. comprehensive acid deposition model. conseils et M. David Gay pour l’aide Atmos. Env. 22, 737-747, 1988. apportée à la préparation des figures. Ces 3. Benkovitz, C.M., C.M. Berkowitz, travaux n'auraien t pu être réalisés sans R. C. Easter, S. Nemesure, R. Wagener, le soutien financier du CRSNG et du S. E. Schwartz, Sulfate over the North FCAR. Si vous désirez plus d'informations, Atlantic and adjacent continental regions: nous vous invitons à communiquer avec Evaluation for October and November nous à l'adresse électronique 1986 using a three-dimensional model [email protected]. driven by observation-based meteorology. J. Geophys. Res. 99, REFERENCES 20725-20756, 1994. The Editorial Board 1. C. Chang-Hasnain, J. Berger, D. R. welcomes articles Scifres, W. Streifer, J. R. Whinnery, 4. Bridgeman H.A., J.L. Walmsley and from readers R.S. Schemenauer, Modelling the and A. Dienes, Appl. Phys. Lett. 50, suitable for, and 1465 (1987). spatial variations of wind speed and direction on Roundtop Mountain, understandable to, 2. J. A. Ruff, A. E. Siegman, and Quebec. Atmosphere-Ocean 32, any practising or S. C. Wang. CLEO'89, paper THK18, 605-619, 1994. 296 (1989). student physicist. 5. Byun D.W. and R. Dennis, Design Review papers and 3. W. F. Sharfin, J. Seppala, A. Mooradian, artifacts in Eulerian air quality models: B. A. Soltz, R. G. Waters, B. J. Vollmer, evaluation of the effects of layer contributions of and K. J. Bystrom, Appl. Phys. Lett. 54, thickness and vertical profile general interest are 1731 (1989). correction on surface ozone concentrations, Atmos. Env. 29, particularly 4. S. Mailhot, N. McCarthy and 105 126, 1995. w e lc o m e . Y. Champagne, CLEO-Europe'94, paper CTuP2, (1994). 6. Flueck J.A., A study of some measures of forecast verification. 5. S. M ailhot and N. M cCarthy, Tenth Conf. on Probability and CLEO’94, paper CWH30, 225 Statistics in Atmos. Sci., Amer. (1994). Meteor. Soc., Boston MA., 69-73, 1987. 6. D. Stryckman, M. D'Auteuil and N. McCarthy, LASERS'94, 327 7. Hoff R.M., R.E. M ickle and C. Fung, (1994). Vertical profiles of ozone during the EMEFS I Experiment in Southern 7. N. McCarthy and P. Lavigne, Opt. Ontario, Atmos. Env. 29, 1735-1747, Lett. 10, 553 (1985). 1995.

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10. G. P. Agrawal, J. Appl. Phys. 56, 9. Lefohn A.S., D.S. Shadwick and paRTtnpacnon ^ ■*> 3100 (1984). V.A. Mohnen, The characterization of Le mouvement pour la santé active

80 Physics in Canada March/April 996 SYMMETRY-VIOLATING NN POTENTIALS IN THE NUCLEUS by A.C. Hayes, AECL, Chalk River Laboratories, Chalk River, Ontario, Canada KOJ 1 JO ABSTRACT The parity-violating and time reversal noninvariant nucleon-nucleon interactions are reviewed, and their manifestation in the nucleus discussed.

INTRODUCTION The full expressions for the weak and strong verte\ Major advances in our understanding of the weak Lagrangians and for the resulting six PNC potential* interaction have come from low energy nuclear N N for χ(ΔΓ = 1), ρ(ΔΓ = 0, 1,2), and ω(ΔΓ = 0, 11 studies. The best examples come from nuclear β- exchange are given in refs. [4,6]. Both quark model decay measurements which established the existence analyses [4] for the weak matrix elements (N M of the neutrino and the fact that the interaction does JC . I N) and theoretical nuclear structure analyse* not conserve parity. The very high precision /3-decay [6] of experimental data indicate that of the measurements that are possible today provide stringent corresponding six coupling constants, F„, F0, Ft, F,. tests of the weak currents in the Standard Model. Test and G0 and G ,, only the isoscalar F0, coefficient ol of the weak interaction from semi-leptonic processes π, ρ, ω the p-potential and the isovector FT, coefficient ol have been reviewed recently by Towner and Hardy the x-meson potential contribute importantly. The [ 1 ]. In this article I will concentrate on another aspect expressions for these two PNC potentials are: of the weak interaction, namely, the non-leptonic part. F. rtP In particular, I will discuss the weak parity-violating - i V ™ c = , - i ^ ( τ ,Χ τ 2)ζ (σ,+σ2) ·Γ Y,(.rr ) and time-reversal-violating nucleon-nucleon interactions, and studies of these in low-energy F Λ ffP nuclear experiments. -iV™ c = i- ^ ^ T| ·τ2( 1 + p ,Kp| + o2)

The weak interaction is responsible for pure lcptonic t· Υ,ίχ,) (1) processes such as μ-decay — er + ve + νμ), semi-leptonic processes such as /3-decay (e.g., n — p N N where mT (mp ) is the pion (rho) mass, M the nucleon + e~ + vc), and non-leptonic processes such as Λ 0 mass, and μ ν is the nucleon vector magnetic moment, — p + T" decay. The three classes of the weak Fig. 1. The one-meson-exchange contribution to the weak Pv=3.7. Here the z-symbol on the isospin vector r, parity-violating NN interaction. Here one nucleon emits interactions can be split further into two parts x r2 indicates the third component of the vector. depending on whether strangeness is conserved or not. a meson via the weak iiXeraction (depicted by the crossed- Also, r = r, —r2, χτ = mTr and Ρ,(λγ) = (1 + In the case of the non-leptonic weak interaction cirde vertex and a second nucleon absorbs the meson via the strong interaction (depected by the open-circle vertex). l/x)Y0(x) with F0(x) = e ~ x!x. The coupling constants information on the strangeness changing FT and F0 involve the product of one weak and one (AS = ± 1) part of the Hamiltonian is obtained by strong vertex coupling constant and their strengths studying the weak decays of elementary particles, for coupling constants for the weak NN potential would remains a central issue in PNC studies. example, the decays Λ — N r , K — 2τ, 3x, Σ provide very useful tools for verifying the quark — N r . However, for the strangeness conserving part model caclulations. The different isospin structure of the two potentials of the Hamiltonian, the allowed strong interaction means that different linear combinations of F0 and processes will generally render unobservable any THE PARITY VIOLATING NN POTENTIAL FT are involved in PNC effects in different nuclei. expected manifestation of the weak interaction. Thus, The strong NN potential is well described in terms For example, a parity mixing between two states thai it is not feasible to study the A S = 0 non-leptonic of the exchange of mesons (χ,ρ,ω, ...) between the differ by one unit of isospin is determined solely H, part of the weak interactions using elementary particle nucleous. A natural extension of these models for the FT, while a mixing between two states that differ by processes. However, the weak Hamiltonian gives rise weak NN potential is a meson exchange model in a proton (neutron) excitation involve a constructive to a weak nucleon-nucleon potential and part of this which one nucleon emits a mesons through the weak (destructive) linear combination of F0 and FT. Thu* potential does not conserve parity. Manifestations of interaction and a second nucleon absorbs the meson in principle, measurements of PNC effects in three the parity nonconserving (PNC) weak NN potential via the strong interaction (Fig. 1). The studies of or so ruder could determine reliable values for the are seen in the low energy nuclear physics processes. parity violaiton in the nucleus are carried out in the weak coupling constants. These processes, though difficult to measure and to low-energy regime. This, taken with the fact that the calculate, provide the only source of information on NN potential is strongly repulsive at short distances, Evaluating matrix elements of the PNC potentials the AS = 0 non-leptonic weak interaction. means that only the lightest mesons are important for between two-nucleon states requires a transforms!ion the PNC potential. Thus, we might expect the one- of the wave functions from a single particle coordinaie The goal of studies of parity non-conservation in the pion exchange diagrams to dominate. However, it system to a relative and centre of mass coordinate nucleus is to determine the strength of the coupling turns out that CP invariance severely restricts the one- system. The required coefficients (Moshinsky consttants for the weak NN interaction, and to pion exchange cortriutions to the PNC potential. The brackets [5] ) for this transformation are known for determine the interplay between the strong and weak limitation arising from C P invariance, which applies harmonic oscillator wavefunctions. However, the interactions in the nuclear many-body system. equally to any neutral pseudoscalar (e.g., xu, tj°, eigenfunctions of the harmonic oscillator potential are Extracting information on the coupling constants for etc.) meson, is called Barton’s Theorem. Baiton [2] not the eigenfunctions of the nucleon-nucleon the parity violating NN potential from such and later Henley [3] showed that for these mesons interaction. The most serious shortcoming of the measurements requires knowledge of both the weak the P-violating meson-nucleon vertex function is not harmonic oscillator wave functions is their inability interaction and of the effects of nuclear structure on invariant under CP and must vanish for CP-invariant to describe the short-range repulsion of the NN its manifestation in these rare nuclear processes. The weak interactions. For the charged pions ( x ±) a C P interaction. This strong repulsion means that as nonleptonic weak interaction is an interaction between invariant coupling can be constructed, but it is r — 0 the relative wave functions go more rapidly the quarks and is mediated by the W and Z bosons. restricted to an isovector (ΔΓ = 1) interaction. For to zero than given by uncorrelated oscillator functions However, in the low-energy regime of the nucleous this reason contributions to the weak PNC potential However, the physics of the shott-range repulsion can it is more efficient to describe the weak interaction arising from the exchange of vector mesons, be incorporated phenomenologically by mu k ply ing in terms of an effective potential between nucleons particularly isoscalar (Δ Γ = 0) p-exchange, are the two-body potentials by a short-range correlation mediated by mesons. The physics of the weak important. Significant contributions to the PNC function. Thus we write nucleon-meson amplitudes (N M | JC . | N) then potential are then expected from x,p, and ω-exchange. appears as an effective weak N — NM coupling ^PNckr) — VpNc(r)ê(r)’ (2) constant. These effective coupling constants are The expressions for the weak PNC potentials are calculated within quark models for the nucleons and obtained by combining one strong and one weak NM- where g(r) is some function that tends to zero as mesons starting with the fundamental weak interaction vertex Lagrangian with the meson progator, and r — 0 and tends to unity for large r. The standard between quarks. Reliable values of the effective taking the non-relativist ic limit of the vertex functions. choice is that made by Adelberger and Haxton [6]

La Physique au Canada mars à avril 1996 81 who used g(r) = [ 1 — exp(—ar2)( 1 — br2) ] 2 with multipolarity (and necessarily of opposite parity) are M = ^ > 2] W =0.58^ ; * m e V (6) a = ΙΛβη~2 and b = O.f&Jm “ 2 obtained from the emitted. A parity-violating asymmetiy can be detected work of Miller and Spencer [7]. Typically, the short by searching for circularly polarized photons resulting where ψ, and iip are the s- and p-wave resonance range correlations reduce the τ-exchange matrix from the interference between the two types of wave fonctions. elements by a factor of — 1.4 and the p-exchange by radiation. Alternatively, if the niclear level has been polarized, a search can be made for an asymmetry - 3.6 [6]. The observed magnitude of M is about as expected of the emitted photon relative to the direction of since the densky of states in compound systems is polarization. DETECTION OF PARITY VIOLATION IN THE about a thousand times larger than in light nuclei and NUCLEUS the average PNC matrix elemeik there is — 1 eV. Several such experiments have been performed [ 8 ]. The parity-violating potential is a very small part French et a l. [12] have developed a microscopic These are three very favourable cases were both (10“ ' - 10 “ *) of the total Hamiltonian for a nuclear framework for a statistical treatment of niclear sources of amplification of the PNC signal play a role. system, H = Hq + v m c- Thus, it can be treated in properties. The formalism has been applied These occur in 18F, ‘*F and 21Ne where parity perturbation theory, and the eigenfunctions of H can successfully to studies of strength fonctions of poskive doublets are found in the low-lying bound states of be written parky operators, such as the quadrupole operator, in the nucleus. Most of the theoretical work has compound nuclei. Tomsovic [ 13] has proposed an concentrated on these three doublets and detailed extension of the theory for studies of PNC matrix *·/♦ “ $/·*·+ ,E analyses havebeen carried out within the shell model E + - E _ elements. The first step in this direction has been taken framework. [6]. In the case of 18F there is a 0“ , 0 + — j+ > are - 1 eV. compared this to the measured value of M to extract of the 0 “ 1081 MeV state yield a zero result, and In a light spherical nucleus a typical nuclear splitting a range of values for F t and F0. theoretical analyses of this resuk indicate an upper between states of the same 7 but opposite parity is bound on the value of F t th£ is consistent with zero. E + — — 1 MeV, so that the odd parity amplitude An example of a violation of a parky-forbidden While this bound is allowed by quark model is £F — 10 However, in complex nuclei one finds selection rule is the a-decay of the excked 2 “ (8.87 calculations of the effective weak coupling constants, situations where the energy splitting between states MeV) state of 160 to the 0 + ground state of UC; it requires considerable cancella ion amongst different 7 + and 7“ are considerably smaller that 1 MeV, and 160(2 “ 1 — a C + a . The α-paiticle has spin/parity model contributions. The unexpectedly small value in these cases there is an amplification of the PNC 7 = 0 + , and k can carty away L units of angular of FT has in part motivated the more recent searches signal. Indeed, many of the PNC searches focus on momertum. Thus, in the absence of parky violation, for parity-violating effects in different nuclear mass parity-doublets, i.e ., closely spaced 7 +, 7 “ pairs. only states in 12C wkh 7 = 2 + L and parky II = regions. Exploiting this enhancement can have its ( - ) 1+L can be populated by the decay of a 2 “ state disadvantages when it comes to interpreting the A parity-violating α-width of Γα = (1.03 ±0.28) x The largest parky-violating effects have been seen in measurements. This is because very precise 10“ 10 eV has been measured [ 15] for this stale. measurements of the (helicity dependent) longkudinal knowledge of the nuclear wave functions is needed This width arises from a 2 + amplkude J admixed analyzing powers for polarized neutron scattering. In to extract information on the weak interaction — into the 2 ~ state, and the magnkude of the PNC neutron transmission experiments on heavy nuclei, considerably more precise than is needed in most width is proportional to 3 2. Unfortunately, the the parity-violating asymmetries, which are defined analyses of parity-conserving observables. The largest uncertainties in the calculation [ 16] of this admixture as the fractional difference of the resonance cross PNC signals are seen in heavy nuclei where nuclear have proved too large to extract information on the section for neutrons polarized parallel and antiparallel levels ate very closed spaced, but the nuclear structure weak potential from this measurement. to their momentum. problems become enormously harder as the complexity of the nucleus increases. For this reason, P = (4) THE ONE-BODY PNC POTENTIAL the approach to analyses in light versus heavy nuclei στ +a have followed very different paths. The PNC potentials are two-body potentials, and the can be as large as 10% [ 10]. These measurements largest uncertainties in evaluating their mkrix Parity inversion refers to the spatial transformation are made on p-wave resonances in compound niclear elements between many-body niclear states arise from r — —r, which implies a momentum transformation systems such as 238U and 232Th [11]. In these the uncertainties in nuclear wave functions themselves. Diserkanglingthe nuclear structure from k — —k. The angular momentum vector (L = r x systems the energy separation between opposite parky the underlying weak PNC matrix elements is the most k) and the spin vector (a) are unchanged under parity. j-wave and p-wave resonances range from 0.1-100 challenging aspect of any theoretical analysis ot Thus, measurements usually involve searches for eV. The mixing of one r-wave state in a p-wave state nuclear parky violation. Insight into the complexkies parity-odd observables such as (a.k), which can arise leads to a longitudinal asymmetry involved and into any pertinent shortcomings wkh the from an interference between a parity-conserving and i L (5) model wave functions can be obtained by starting wkh a parity-violating amplitude. These parity-odd P = 2 an analysis of the problem wkhin a one-bod) correlations are first order in 5 . Alternatively, one approximation. Michel [17] derived an effective one- can search for violation of parity-forbidden selection Here y * and γ|] are the neutron reduced-widths body PNC potential, which allowed him to evaluate rules, such as a parity-forbidden α-decay, and these evaluated at the p-wave resonance energy. The actual PNC asymmetries using Nilsson model wave are proportional to ff2. asymmetries involve a summation over many r-wave functions for a variety of spherical and deformed resonances since k is unlikely that P is dominated by nuclei. In the case of parity-odd observables arising from an the nearest-neighbour opposite-parity resonance. The interference between a parity-conserving and parity- large size of the PNC asymmetries in compound Typical many-body nuclear calculations assume an nonconserving amplitude a second enhancement of systems arises because of (1) the small energy inert core set of nucleons (interacting only via the the signal is possible. The PNC effect is proportional denominators in J and (2) the favourable ratio of to (Oi/W Q) average nuclear potential) and a valence set ol 2 !r ------, where is the matrix j-wave to p-wave neutron widths. interacting nucleons. The one-body PNC interaction Ο0{PC.)> ’ ' Up/fc between two nucleons in valence states | a) element of an observable which is now non-zero The close spacing between the resonances reflects and ] b ) can be derived from matrix elements of the because of the P-violation and < 0(PC)) is the matrix their complexky and they correspond to highly excked two-body interaction V w c by summing over all element of the parity-conserving observable. Thus, compound states of the nucleus. The wave fonctions configurations in the core, by choosing cases where nuclear structure effects of these resonances involve 103-106 single particle render <0(PC)> to be very hindered, the PNC signal components, and their structure can only be described <6 I Upttc \ a> = H b .c I IW(1,2) I a , c> (7) can be amplified significantly. statistically. In the statistical model the neutron c reduced widths y * and -v. and the PNC mixing Most of our knowledge on the PNC potentials have matrix elements < Vm c ) ate treated as independent Here the two-body matrix elemek is antisymmetric, come from measurements o f parity-violating Gaussian-distributed random variables with zero i.e ., k includes both the direct and exchange terms. asymmetries seen in γ-decay, or in the scattering of mean. Using the known values of the resonance The matrix elemeiks of the one-body inet erection can polarized nucleons from nuclei. In the case of the energies and reduced widths, the root-mean-squared be expressed in terms of an analytic one-body photon decay of an excited parity-mixed state of the PNC mixing matrix elemeik M can be determined operator. The chosen operator acts as a meaningful, mcleus (eq. (3)) to a final sttte of definite parity, both directly from a set of experimental values of P. A well-defined approximation to the two-body PNC magnetic and electric radiation of the same maximum likelihood analysis [11] yields a value potential if the associMed effective coupling constants

82 Physics in Canada March/April 1996 are not dependent on the core states involved in the TABLE I. Contribution from each component (F,r,Fo, ...Gi) of the two-body Vpsc to e for sum (7). The simplest and most appealing one-body closed-shell-plus-one configurations for five choices of the closed-shell core. operators that violate parity, but not time-reversal invariance, are the isoscalar and isovector axial 1 1 1 208 p b 232 T b operators 7- p and 7-pr. The appropriate effective T C o * C a Z r N = 8 N = 20 N = 50 N = 12 6 N = 1 4 2 coupling constants are defined as Z = 8 Z = 2 0 Z = 4 0 Z = 8 2 Z = 90

0 1 1° « ° e ' 1 ° (b II 7· 7|| a > O p -O s l p - l s 2 p -2 e 3 p -3 s 3 p -3 s

Fw .2 0 5 - .1 5 7 .1 2 6 1 1 9 132 - 144 C I _ w f o c ‘ ll« > F 0 - 156 - .1 4 3 - .1 3 6 -.1 4 0 001 -.0 0 1 .001 001 001 (b II 7 · pr II a > F l f 2 .0 0 0 .0 0 0 0 0 0 0 0 5 .0 0 5 G o -.0 1 4 -.0 1 4 -.0 1 4 - 0 1 5 -.0 1 6 G, .0 0 7 -.0 0 8 .0 0 8 - 0 0 9 0 0 9 The contribution of each of the six terms in VPNC to the one-body coupling constants c and r 1 has T o t a l - 170 .2 1 3 -.157 -.166 - .1 5 0 .1 3 5 - .1 5 5 - 129 - 1 6 0 128 been calculated by Hayes and Towner [ 18] assuming ,.) e V 2 4 3 0 2 .5 2 .7 2 .5 2 .3 2 6 2 .2 2 7 2.1 a single nucleon outside a closed-shell configuration. The results are summarized in Table 1.

Most striking is the lack of any strong shell or mass using the operators 7 ■ p and ά - pr. The tw o dependence in the coupling constants f 0 or e1. The distributions are very similar over the entire excitation total isoscalar and isovector PNC strengths remain 060 spectrum. However, for some individual states large almost constant with A (the mass of the nucleus). differences occur. This suggests that whilst the Furthermore, the large neutron excess in heavy nuclei operator 7- p provides an excellent approximation to has little effect on the values of the effective coupling the overall PNC strength function in the nucleus, it constants. There are two competing factors should not be used for the extraction of PNC coupling determining the mass dependence of c. First there is constants from measurements on isolated parity the dependence on the size of the nucleus, which doublets. increases linearly with the harmonic oscillator length parameter, botA 1®. Matrix elements of 7- p scale T-VIOLATION IN THE NN INTERACTION with 1/b, while matrix elements of VPNC scale roughly with I/b2. Thus, if the number of core Since the discovery of CP-violation in kaon decay orbitals which are summed remained frxed, t would over thirty years ago, the origin of the effect has still scale like I/b approximately, and thus decrease not been identified. There have been many searches roughly as A _ " “ . However, this scaling with the for other CP-and T-violating effects, but nothing has oscillator parameter is strongly offset by the increase been seen in systems other than the neutral kaons. in the number orbitals being summed as A increases. A number of models have been proposed for the In general, the two effects compensate, resulting in interaction responsible for the observed CP-violation. an approximately mass independent effective coupling The observed effect can be accounted for within the constant. minima] standard model through a CP-violatingphase in the Cabibbo-Kobayashi-Maskawa quark mixing E'(MeV) To examine the expected distribution of the PNC matrix. Akernatively, new interactions requiring an strength in the nucleus we can examine the strength extension of the standard electroweak model may be iunctions of the effective one-body operators. The Fig. 2 The distribution of one-body PNC strength built responsible, and the predictions of some of the on the J = 111* ground state of ‘T . In this figure the proposed models are quke different in systems other axial operators 7■ J and 7 · pr are exactly analogous height of each line represents the magnitude o f the P N C to the electric spin dipole operators 7 - Fand 7* rr. than the neutral kaons. T-vioIation in the NN matrix element (in arbitrary units) and the energy interaction can occur simukaneously with P-violation, They differ in their helicity properties, but if we position o f the line is the excitation energy o f the or as a P-conserving T-violating, interaction. confine ourselves to a 01)b) — 11)ω calculation, (i.e., corresponding T = l/2 or T «3/2 J =1/2“ excited state. However, in contrast to the PT-violating interactions, a calculation where the positive and negative parity The P N C matrix elements were obtained from a 1(>ω shell interactions that violate T but conserve P do not arise states differ only by the excitation of a nucleon model calculation. The upper panel of the figure shows in the standard model. In this section we discuss through one oscillator shell), the distribution of the the one-body strength derived from the two-body P N C interaction using eq (7). The lower panel shows the attempts via low-energy measurements to put limks matrix elements of 7 - 7 and 7■ p are identical. The strength obtained using the operators e° a · p and on the strengths of either form of T-violation in the operators σ,τ, and σ-r generate the group SU(4), and e1 a · prt where the coupling const aits e° and e1 are taken NN interaction. the irreducible representations of this group form the to be orbital independent. W e note the very snail fraction Wigner Supermultiplets. If the nuclear force were of the total strength to the firS 1/2 ~(100 keV) state. This independent of spin and isospin, i.e. invariant under is the state that is relevant to the parity-violating y-decay The time-reversal noninvariant low-energy NN the Wigner SU(4) symmetry, the distribution of in ,9F. poteitials can be described in terms of a single meson matrix elements of any set of operators 0(r), 0{r)a, exchange in which one of the N — NM vertices 0 ( γ) τ , and 0(ι-)στ would be the same. The nuclear the y decay of the 1/2 - state. The total (isoscalar involves a Ρ,Τ-violaling or T-violating P-conserving Hamikonian does contain SU(4) noninvariant terms, and isovector) one-body PNC strength buih on the non-Ieptonic Hamikonian. Measurements of T- such as the Heisenberg (τι ·τ2) interaction and the ground slate of 19F is shown in detail in Fig. 2. The violation in the nucleus require polarized nuclear spin-orbit interaction. Nonetheless, the distribution states of 19F were calculated in a lull (0+1 )1)ω shell targets, and are generally more difficuk than searches of operators differing only by an SU(4) rotation model calculation, in which spurious cetlre-of-mass for P-violaling T-conserving asymmetries. The remains similar, particularly in light nuclei. The excitations were removed exactly. There are then over magnitude of a T-violaling amplitude in the nuclear operator TV is the electric dipole operator and ks three hundred 1/2 ~ stales in the nonspurious model wave iunctions is expected to be veiy small, especially strength distribution in the nucleus is determined by space. From Fig. 2 k can be seen that most of the in the case of a T-violating P-conserving amplkude. the giant dipole resonance which lies at about 1.5|)ω, strength of the parity-violating interaction is (!)ω = — MeV) of excitation, and is a few concentrated at high energies, and that the first excited The issues involved in the PT-violating and the T- MeV wide. Thus, from SU(4) symmetry arguments, state involves only a very small fraction of the total violating P-conserving interactions are different and we expect that the strength distributions for 7- p and strength. This points to the need for a very detailed we consider them separately. The most stringent tests 7 -p r also exhibk resonance-like structure. calculation of the structure of this stale before a on the limits of time-reversal noninvariant interactions meaningiul analysis of the PNC matrix element can come from searches for electric dipole moments in To demonstrate this in a realistic calculation we be extracted from the γ -decay measurements. The the neutron or in neutral atoms. However, consider the nucleus 19F which has a 1/2 + ground upper panel of the figure shows the PNC strength investigations of the role of T-violation in the NN state. Ihe parity mixing between the ground stale and obtained using the full form of the PNC potential via interaction have concentrated on searches in the the first excited 1/2 ~ state has been deduced from eq. (7), the bottom panel shows the resuks obtained nucleus. We first consider the simukaneous violation

La Physique au Canada mars à avril 1996 83 of time reversal invariance and parky conservation. situation seen in P-violation, where p-exchange plays sections for neutrons polarized parallel and arkiparellel Ρ,Τ-violalion in the NN interaction may be studied a dominant role. to their momentum, P PT**al — oMo\ + e l, implies in γ -decay and in neutron transmission on polarized simultaneous P- and T-violalion. The P,T-violating nuclei. PT-violalion is always accompanied by P- As noted above, the ratio of the Ρ,Τ-violaling to P- asymmetry arises through a term in the scattering violalion alone, and the ratio of the two asymmetries violaling asymmetries is the significant observable and amplitude proportional to e · (* x j ) . Here σ I and el is the relevant observable. A symmetry-violating this is proportional to the rat io of the matrix elemerks are the total scattering cross-sections for neutrons potential VF + VFT has the effect of changing a of Vr and VF,T. Herczeg [19] has pointed out that polarized parallel and arkiparellel to (k X j), a and k nuclear slate | a ) to a state \A), given by if a reliable calculation of (a'\VF,T \ a) is not are the neutron spin and momerkum and J is the target available, an estimate of the ratio A P TIAP combined spin. \A> - |n>+E J i l l ■ wkh a measured value of the P-violating effect may give a more reliable estimate of (o'] V F T \a) than In a two-stale mixing approximation, the ratio of the would an unreliable calculation of k. To this end, Ρ,Τ-violating to P-violaling asymmetries in the « a '\ V l’ \a) + ia'\V,,-T\a)) (9) Herczeg defines the ratio k. neutron measurements is given by

where the stale | a ') is of the same angular z á r M '\VFT\a) _ g%„ ' . * , \ V - TU P) ffltNN momentum as |a> but of opposke parity. (12) : ---tVW’ •(16) *h the calculated value of κ implies The ratio * has been evaluated [21] as a function of that the required accuracy is about P F1J P p - I 0 '3. _2 nuclear mass assuming a single nucleon in a closed- Finally, we consider the T-violating P-conserving ^ 7 .T 0) " - S ^ N H g .N N j ^ e - >T, T2FiC*.), shell-plus-one configuration. The magnkude of « is found to be about 5. and to display very Iktle mass (TVPC) NN potential. In the case of the TVPC dependence. Griffiths and Vogel [22] have also irt erection, the form of the meson-exchange potential ’■»“ iát**"·-* calculated * for specific rare-earth nuclei, using the has been shown by Simonious [24] to be severely quasiparticle random phase approximation. They find constrained. No τ-exchange or p°-exchange is o./fUntt.) (io) a very similar range of values. These resuks are allowed; Only p ± and A x (or heavier) mesons can significant because they suggest that the ratio of the contribute. The A x meson is considerably heavier where potential form the core nucleons. Thus, only a few standard notation in which a ‘bar’ over the coupling i^ j· :>Jn (13) valence nucleons can contribute to a TVPC ’ constant indicates T-violation and a ‘prime’ P- observable. violation. A *bar’ and a ‘prime’ together indicates PT- where τ ' L’ is the irregular mukipole available due violalion). The overall form of the p-exchange Ρ,Τ- to Ρ,Τ -violalion while xL is the mukipole present in violating poleikials is the same as for τ-exchange the absence of V F + V F T . The P-violaling effect in The most stringent limks on g„ come from an except for one key difference in the isovector the same transkion is proportional to analysis [25] of the experimertal limks on the electric potential. There the relative sign between the two dipole moment of 199Hg and of the neutron. These implies I β,Λίν I s 9 .4 x 10- J . terms is negative for p-exchange and poskive for Ap (14) τ-exchange. ' <β||»ϋ1>0 ' To obtain insight into the properties of the P,T- The measurement in ,n H f yielded French et al. [ 12 ] studied the sensitivky of spectral potentials and to estimate the relative importance of fluctuations and strength functions in the compound the different components we turn to the effective one- bn < J\E L \i) raidear regime to a time-reversal noninvariant term -0 .7 ± 0 .6 (15) body potentials. These are derived in exactly same Fe99Hg. reversal invariant Hamikonian. The data set studied Futhermore, p-exchange interaction gives no included 1702 levels in 32 nuclei. Since the analysis contribution for any isospin channel. For charge- Ρ,Τ-violalion can also be probed by study of the of compound nuclear resonances require enormous nonsymmelric cores (N * Z) these terms give a fmke transmission of polarized neutrons through polarized model spaces, French et al. used their spectral contribution, but generally small. The vector meson nuclear targets [23]. These experiments are an averaging formalism for this analysis. The resuks exchange coikrftiutions to Ρ,Τ-violalion are about two extension of the neutron transmission measurements were expressed in terms of a coefficient «*Γ, which orders of magnkude smaller that the T** 1 τ-exchange on unpolarized targets. In the case of polarized targets, is the ratio of typical TVPC NN matrix elements to matrix elements. This is in sharp contrast to the the fractional difference of the resonance cross those of the symmetry-conserving shell model

84 Physics in Canada March/April 1996 involves mixing between several states, have y e to TABLE II. Isovector ir-exchange, Vpp, and isoscalar ^exchange, Vp, matrix elements evaluated achieve the required accuracy to extract reliable for a ( losed-shell-plus-one configuration for six choices of the closed-shell core. The weak interaction coupling constants. coupling constants are g^NN = l.u x 10“" and = —11.4 x 10-7 .

In heavy nuclei, where the parity violation between 160 208 p b 2 3 2 T h ,0 Ca 90 Zr ,3 8 B a compound resonances is analyzed within the statistical N = 8 N = 2 0 N = 5 0 N = 8 2 N = 126 N = 1 4 2 Z = 8 Z = 2 0 Z = 4 0 Z = 56 Z = 8 2 Z = 9 0 shell model, the present indications are that the models need to be extended. To date statistical calculations have been confined mainly t0 studies of positive parity O p — Os i p — I s 2 p - 2 s 2 p — 2 s 3 p — 3 s 3 p — 3 s operators. For most of these, the strength function of the operator is determined by the same model space < \ 'i > in eV xlO-4 1 084 0 .8 7 5 0 .7 0 8 0 .7 7 9 0 .6 0 8 0 .6 3 3 that determines the level density. In the case of i V p > ín eV 1 513 1 .5 5 0 1 .5 3 5 1 5 7 6 1 581 1 .6 0 0 negative parity states, the level density is determined by the so-called irt ruder state. The irlruder state is *(,) - 8 2 - 6 4 - 5 6 - 4 4 - 4 5 the state of maximum J from the next highet shell which is pulled down one shell by the very strong spin-orbit interaction in heavy nuclei. The angular momentum difference between the opposite-par its irlruder orbital and all other orbitals in the shell means TABLE III. Weak PNC coupling constants. The theoretical values and range are from the quark that the intruder cannot contribute to the one-bod} model calculations of Deplanques e t a l. [4] and th

interaction. The limit at the 99% confidence level is complicated way that the estimated [4 ] values for New experiments are planned to measure parity- I a T \ < 2 x 10- 3 . Haxton era/. [25] have related the coupling constatas are assigned large uncertainties. violating asymmetries in polarized-neutron scattering a T to the coupling constant gffNN in 199Hg by The "best values" and "reasonable range” for the over a wider range of nuclear masses. In cortrast to comparing matrix elements of V jvpc with matrix two PNC coupling const arts FT and F0, resulting heavy nuclei, analyses of the PNC matrix elements elements of the residual strong interaction in a shell from the quark model calculations, along with the in light nuclei show that the one-body part of the model calculation. They find that the limit on a T values obtained [6 ] from the best fit to experiment, irteraction dominates there. A current topic of interest implies I . |< 2 .5 . are tiven in Table III. The allowed range on the is the issue of how the role of the one-body versus theoretical values for the coupling constants means two-body parts of the PNC irteraction vaty as the There has been one published measurement o f a T- that even very precise experimental determinations intruder orbital is lowered in energy. Ideally, one violating P-conserving correlation in the scattering of FT and F0 will not provide constraints on the would like to measure the effects in a common nucleus of polarized neutrons on aligned 163Ho targets. fundamental weak irteraction between quarks. that can be calculated both within the regular shell These measurements searched for a dependence of The calculations require the evaluation of three- model and the statistical shell model. the forward elastic-scattering amplitude on the T- hadron matrix element o f a four quark-operator, violating P-conserving correlation term ( o - J x k) . near future. These are expected to provide improved While much progress has been made in our attempts Thus, very detailed knowledge of the nuclear wave limits on the corresponding coupling constant. to understand nuclear parity violation, a number of functions is needed to obtain a reliable prediction of open questions remain. The original motivation of the the matrix elements. In particular, at least 2Κω of REFERENCES program was to extract information on the excitation must be included in the model ^ ace and fundamental weak interaction between the quarks spurious eerier of mass excitations must be eliminated [1] t.S. Towner and J.C. Hardy, in The Nucleus as a from the PNC meson-nucleon coupling constants. exactly. Structure theorists have taken advartage of Laboratory for Studying Symmetries and Fundamental However, this hope has been blighted by theoretical the rapid advances in computer technology and Interactions, eds., E.M. Henley and W.C. Haxton difficulties at the particle physics level. In principle, modern shell model codes can now handle very large (W orld Scientific. Singapore, 1955) to be published. the weak meson-nucleon amplitudes, and hence the model spaces. Recently, these advances provided the [2] G. Barton. Nuovo Cimento 19 512 (1961). corresponding coupling constants, can be calculated first multi-ΙΙω calculation of 2]Ne, which in turn starting with the standard electroweak interaction provided the first set of consistent values for FT and [3] E.M. Henley. Ann. Rev. Nucl. Sci. 19. 367 (1969). between quarks. However, the elementary W and Z F0 for the PNC measurements in the three parity- exchange occuring inside the weak meson-nucleon doublet cases. Calculations in light nuclei, where the [4 ] Bertrand Deplanques, John F. Donogfiue, and Barry vertex are dressed by hadronic effects in a sufficiently parity mixing is not confined to a doublet but instead R. Holstein. Anns. Phys. 124. 449 (1980).

La Physique au Canada mars à avril 1996 85 OUTFLOWS FROM SPIRAL GALAXIES

by Judith A. Irwin, Dept, of Physics, Queen's University, Kingston, K7L 3N6, Canada, [email protected]

SPIRAL GALAXIES — A VIEW THROUGH (seen as the faint band of light stretching but occupy large filling factors and THE TELESCOPE EYEPIECE across the sky), the stars that are visible cover most of the observable sky, though are only the relatively nearby ones, out to with decreasing intensity as a function of When most of us envision a "galaxy”, we distances of a few kpc (1 kpc = 3.1 x distance from the Milky Way plane. They tend to think of giant spirals, both 10,u m) compared to the 8 kpc distance to are also tracers of energetic phenomena structured and beautiful, often displayed the Galactic Center'. Starlight is scattered and the cosmic ray component allows us with prominence on the covers of and reddened by dust by the same to map out the structure and direction astronom y texts (Fig. 1). The image is at processes which dim and redden light of the Galactic magnetic field from optical wavelengths, as if peering through from the setting sun. Since interstellar observations of synchrotron polarization. a very powerful telescope on a clear, moonless night. We see a bright flattened grain radii tend to be in the range, £ a few The total ISM m ass constitutes hundredths to a few tenths of a μ π , disk consisting of =10” stars too crowded approximately 10% of the galaxy's total however, wavelengths sufficiently longer over the field of view to be resolved observable mass. Most of this mass is than this particle size will propagate over individually. Prominent spiral arms wind split roughly equally between two neutral through the disk emerging from a glowing scales of Galactic proportion, essentially components. One is neutral atomic central bulge, and around the disk is a without interaction. Consequently, hydrogen (HI), which is ubiquitous roughly spherical halo region sparsely observations at mm, cm, and some throughout the Galaxy and detectable populated with globular star clusters, each infrared wavelengths provide us with through observations of the ground state one containing perhaps half a million stars. useful probes of the large scale structure hyperfine transition at υ = 1420.406 With careful observation, we can discern of the Galaxy. numerous details, bifurcated spiral arms, MHz. HI (T = 100 K) is seen in cloud subtle colour differences, dark dust lanes THE INTERSTELLAR "VACUUM" - A structures, in wispy filaments, arcs and threading along the arms or reddish ionized BROADENING PERSPECTIVE plumes, and as smooth warmer intercloud gas. It is extremely useful for mapping out hydrogen (HID regions associated w ith the When a radio telescope is pointed at the the large-scale rotation of the Galaxy from brightest, hottest stars. The view is Milky Way, the resulting view is quite Doppler shifts of this spectral line. The breathtaking, and not at all incorrect. different from the optical picture described Indeed, some might argue that this picture above. Stars, being weak emitters at second component is molecular hydrogen is quite adequate, given that most of the radio wavelengths, disappear from view (H2) which congregates in denser clouds observable mass of the galaxy is locked up and instead, depending on the tuned and is more concentrated towards the in stars which emit black body radiation at frequency, the sky is filled with emission galaxy’s plane than the HI. There does not predominantly optical wavelengths. But from the "vacuum” between the stars. appear to be any intercloud H2, since the there's more going on here than meets the Interstellar space is filled with numerous radiation field in low density regions eye. components (including dust), collectively between clouds is capable of dissociating known as the interstellar medium (ISM). the hydrogen molecule. Interstellar dust is The ISM is not uniform, rather its correlated spatially with dense molecular constituents occupy volumes of space of clouds and it is believed that molecules various size and cover many orders of form most efficiently on the surfaces of magnitude in density and temperature — these grains. Unfortunately, H2 has no from hot "coronal” gas with densities as dipole moment and is therefore low as 0.001 particles cm3 and undetectable under normal interstellar temperatures as high as =10β K to conditions2. Therefore, the quantity of molecular cloud cores with densities as molecular hydrogen is normally inferred high as 1078 particles cm3 and (with some controversy as to the temperatures as low as =10 K. Although conversion factor) from observations of the the densest of clouds is still orders of next most abundant molecule, carbon magnitude rarer than the best vacuum monoxide, which is collisionally excited by attainable in earth-based laboratories, the H2. CO has several accessible when integrated over the extremely large distances of interstellar space, column rotational transitions in the mm and densities can be considerable (e.g. 1022 sub-mm regimes (e.g. J = 1 —» 0 Fig. 1 The nearby galaxy, M 31 (The particles cm 2 for neutral atomic hydrogen) corresponds to υ = 115.271 GHz). Andromeda Galaxy) and its two and the emission is often easily small companions. The image is at So far as we know, this description of the optical wavelengths in which the detectable. emission is predominantly from ISM in our own Galaxy is applicable to stars. Image available through the Much of the volume of the ISM is taken most other spirals, though it is difficult to home page of "Students for the discern the detailed structure of the Exploration and Development of up by hot, low density ionized hydrogen Space" (http://seds.lpl.arizona.edu/). (called coronal gas) and by low density various components in other galaxies due cosmic rays which were accelerated in to lack of sufficient spatial resolution at high energy regions like supernova shock the greater distances. There are also Decades of study of our home Galaxy, the waves. The ionized hydrogen is differences between galaxies, however, Milky Way, have provided us with a view detectable from its Bremsstrahlung especially in the relative quantities of the which is very similar to the description emission in the soft X-ray regime, which various components, and in the agitation above, the sun and its planets near an requires satellite observations. they are experiencing from internal outer spiral arm orbiting the center of the Ultra-relativistic (e.g. γ = 1000) cosmic energetic events. Galaxy with a period (a few x 10° yr) ray electrons spiral around Galactic dictated by the Galactic mass distribution. magnetic field lines and can be detected THE VIOLENT INTERSTELLAR MEDIUM An optical 3-D map of the Milky Way, by the subsequent synchrotron emission however, becomes sketchier with which is radiated as a continuous Recently, our understanding of the increasing distance from the sun, due to spectrum in the cm-wavelength radio interstellar medium (ISM) in our own and obscuration by interstellar dust. Indeed, if regime. These two components contribute other spiral galaxies has undergone a we look along the plane of the Milky Way a negligible amount of mass to the ISM, dramatic change. Twenty-five years ago,

'interstellar absorption varies strongly with position in the Galactic plane. "Under some conditions, e.g. in regions close to stars, molecular hydrogen can attain temperatures of several thousand K in which case some vibrational transitions are observable in the infra-red.

86 Physics in Canada March/April i 996 the ISM was thought to consist only of GALAXY OUTFLOWS order 10,000 km s ', the consequences can quiescent neutral hydrogen in two phases It has been known since the early days of be significant. In some cases, the result is (cool cloud and warm intercloud gas) radio astronomy that some galaxies bipolar nuclear outflow along the rotation which were in pressure equilibrium (Field, experience outflows, but these outflows axis of the galaxy as the hot ejecta takes Goldsmith and Habing 1969). As are in the form of narrow jets originating the path of steepest decreasing pressure satellite-based telescopes were launched, from "active galactic nuclei" or AGNs, gradient away from the nucleus. A good this view had to be modified to include the most likely associated with a supermassive example of bipolar outflow from a nuclear hot X-ray emitting component, presumably black hole at the galaxy’s center. starburst is the galaxy, NGC 3628 (Fig. 2) supplied through supernova explosions Although spectacular, such outflows were in which the outflowing hot gas is visible (Cox and Smith 1974, McKee and Ostriker only seen in distant elliptical galaxies and as soft X-ray emission far from the plane. 1977). With continually improving were not observed in relatively nearby Starburst galaxies are more numerous than AGN in the nearby universe and potentially present us with a clearer view of the physical processes which are involved in driving such outflows.

The first clear evidence for outflows from the disks of spirals other than the Milky Way came from observations of NGC 3079 in w hich HI shells and supershells similar to the "Heiles Shells" of our own Galaxy were detected (Irwin and Seaquist 1990). There are now a number of other galaxies for which there is good evidence for disk-to-halo outflow. Of those displaying HI shells, the complete (but growing) list is still probably less than a dozen (see examples in Irwin 1995). This number increases if we also include galaxies which display radio continuum (from synchrotron emission) thick disks or halos (e.g. Hummel, Beck, and Dettmar 1991). A good example of a galaxy w hich displays both HI disk-halo arcs as well as a dramatic radio continuum halo is NGC 5775 (Fig. 3). The halo around this galaxy is so large (= 16 kpc radius in projection) that the galaxy resembles an elliptical in this waveband. At the same time, considerable structure is observed in the outflow features, potentially providing clues as to the mechanism(s) that formed them. These observations suggest that gas Fig. 2 The edge-on nuclear starburst galaxy, NGC 3628, with optical emission shown in greyscale (both non-relativistic and relativistic) can and overlaid contours depicting X-ray emission due to hot ionized gas. Adapted from Fabbiano et al. (1990), copyright American Astronomical Society, reproduced with be expelled from spiral galaxy disks where permission. the star formation rates are considerably more modest than in the nuclei. The observations, especially at non-optical spirals. Since the 1980s, however, there question arises, then, are the disk outflows wavelengths, we now see the ISM as have also been discoveries of (wider also a result of processes related to complex and multi-phased as described opening angle) bipolar outflows from the massive star formation? above. However, far from quiescent, it is nuclei of spiral galaxies. Some of these now understood to be frothy and seething, nuclear outflows fall into the lower There is good evidence to suggest that the undergoing violent activity, and possibly luminosity end of the AGN category, but disk outflows are indeed related to experiencing outflows as gas is driven not all. It appears that galaxies without starbursting, but starbursting alone does away from the disk into the halo region AGN but which are experiencing strong not appear to be sufficient to account for around it (e.g. Norman and Ikeuchi 1989, nuclear "starbursts” can also produce a the observed features. In the Milky Way, or papers in Bloemen 1991). bipolar outflow. some of the Heiles Shells do appear to be correlated with active sites of star The realization that there is a dynamic A starburst occurs wherever there is an formation and most of the theoretical work disk-halo relationship in our own Galaxy unusually high massive (e.g. a 5 —> 8 Me) pursued to date has focused on modelling crystallized with the discovery of star formation rate. Massive stars live for the structures expected from a rapid input expanding HI shells and supershells of kpc of supernova kinetic energy (e.g. Tomisaka a relatively short (e.g. s 10' years) time scale extending over the disk-haloboundary 1991). However, a difficulty arises when and end their lives in supernova ("Heiles Shells"; Heiles 1979, 1984). the largest HI shells are considered. explosions. Since the star formation Since this early work, other evidence for Obviously, the input energy must be at process itself can occur over timescales disk-to-halo outflows has accumulated, least as high as the expansion energy of longer than this, star births and stardeaths including expanding molecular (i.e. CO) the shell (up to 1066erg). When converted can proceed at the same time. Star shells in the Galactic Center region (Oka et to the required number of input formation activity (and therefore al. 1995), and features over the disk in supernovae, the result can be more than supernova activity) can be enhanced in the various wavebands which spatially 104. This stretches the starbursting nucleus if, for example, a passing correlate with the Heiles Shells (e.g. Koo scenario severely, since most associations companion galaxy perturbs the gas et al. 1991; Waller and Boulanger 1993; of hot, supernova-producing stars in our distribution, resulting in gas transfer Reach et al. 1993). The input energies own Galaxy are thought to contain < 102 towards the center. The build up of gas implied by the HI shell masses (obtained stars, though some may be more populous. invokes accelerated star formation and a from the luminosity of the spectral line) Moreover, even if the energy is available, resulting "burst" of activity from the and expansion velocities (obtained by the large scale HI features can only be formed collective contributions of many individual Doppler shift of the spectral line) can be if the scale height of the disk is also supernova explosions. Given that initial considerable --- energies up to = 106ί> erg unrealistically large (e.g. Heiles 1990). outflow velocities from supernovae are of are not out of the ordinary. This "energy problem" has led some

La Physique au Canada mars à avril 1996 87 researchers to seek other explanations for identified, I would contend that this is the HI supershells. Recent observations of HI supershells in largely because of selection effects. It is two undisturbed, isolated spiral galaxies important to observe galaxies which are In the Milky Way, there appear to be (Lee and Irwin, in preparation; Giguere and highly enough inclined that the disk can in connections between a few outflow Irwin, in preparation) now indicate that the fact be separated spatially from the halo features and "high velocity clouds” . These cloud impact model is an unlikely one for region around it. So far, few studies have these galaxies. The star formation rates in systematically concentrated on galaxies with this orientation. Because the features tend to be faint, it is also necessary to integrate long enough to obtain good signal-to-noise. The radio continuum halo observed around NGC 5775 (Fig. 3), for example, was only detected by combining data from three separate observing sessions, for a total of 6 hours of on-source time using the Very Large Array ( VLA) radio telescope near Socorro, New Mexico. Neutral hydrogen observations also tend to be time consuming, both in the collection and analysis of the data. A single galaxy requires an integration time of approximately 12 hours using the VLA and processing and analysis must proceed on "cubes" of data since a map is generated for every spectral channel. The rewards, however, are well worth the time investment. In a survey of 17 edge-on galaxies in the radio continuum, it was found that virtually every galaxy showed radio continuum extensions beyond the optical boundaries of the disk (Sorathia and Irwin 1995, in preparation; Sorathia 1 994). It is entirely possible then, that at some level, outflows are a common characteristic of all spiral galaxies which are actively undergoing star formation.

What is the ultimate fate of the expelled gas ? Does the gas cool and fall back to the disk again like a "Galactic Fountain” as first suggested some 20 years ago (Shapiro and 14 51 35 30 25 20 15 10 05 Field 1976) or does it leave the galaxy RIGHT ASCENSION (B1950) altogether, flowing intointergalacticspace? For galaxies like NGC 5775 (Fig. 3) the Fig. 3 The edge-on galaxy, NGC 5775, and its interacting face-on companion, NGC 5774, to the radio continuum emission extends so far north-west (i.e. upper right). The centers of both galaxies are marked with crosses. Greyscale denotes the neutral hydrogen emission which is strongest in NGC 5775 along a from the plane (i.e. = 16 kpc) that the halo narrow south-east to north-west path and corresponds roughly to the stellar disk of this resembles an oblate spheroid in projection. edge-on galaxy. Fainter neutral hydrogen emission can be seen extending away from this The existence of halo substructure far from disk in the form of arcs, plumes and extensions. Contours represent radio continuum the plane implies that dynamical processes emission from the synchrotron process, forming an extended flattened halo with considerable are still at work at very large scale heights, substructure. suggesting that at least some mass loss is likely occurring. On the other hand, clouds form part of a cloud stream which observations of X-ray emission from the hot these galaxies exceed that in our own, stretches between the Milky Way and its halo of the galaxy, NGC 891, suggest that and it is therefore possible though not nearby companion galaxies, the Magellanic this thermal gas is bound to the galaxy observationally proven that very large Clouds, as a result of a tidal interaction. (Bregman and Pildis 1994). Some galactic numbers of supernovae may also These connections, as well as the energy circulation models suggest that either congregate in individual clusters. problem described above have led to the scenario is possible, depending on the However, the difficulty in producing HI Cloud Impact model for the formation of HI density of the ISM and the level of energy supershell structures remains. For shells in the Milky Way (see review by input (e.g. Norman and Ikeuchi 1989). Tenorio-Tagle and Bodemheimer 1988), example, in one case, the size of the HI shell is fully half the radius of the galaxy, and now in other galaxies as well (e.g. As yet, we have no direct observational far in excess of any reasonable scale NGC 4631, Rand and Stone 1995). As the measure either of mass loss or mass height. It is therefore worthwhile to name suggests, the HI supershells are circulation rates from a galaxy disk. Some search for some additional source of formed from the impact of clouds onto the theoretical estimates place a mass loss rate energy, besides supernovae, to explain the Galactic disk, in which case the shell for our own Galaxy of order = 1 Mo y r1 observations. Perhaps the disk and halo energy is dictated by the infalling cloud (Völk 1991). Other galaxies are clearly are coupled in such a way that rotational mass and the infall velocity. This allows experiencing higher star formation rates shear can be converted into vertical for much larger input energies since the than the Milky Way, suggesting an upwards motion. Further theoretical work, possibly infalling cloud can be a tidal shred from the increase in the mass loss rate for them. If in the realm of non-linear magneto­ interacting galaxy with an (almost) these estimates are correct, then over the hydrodynamics (e.g. Parker instabilities), arbitrarily large mass. Of course, appealing course of a single galaxy rotation (a few x appears to be required, to cloud impacts as the source of disk-halo 108 years) the ISM, which contains a few supershells requires that the galaxy either times 109 Mo could be significantly (i.e. at THE SIGNIFICANCE AND CONSEQUENCES be undergoing an interaction or at least OF OUTFLOWS levels à 10%) depleted. After a dozen have companions nearby as a potential rotations, a naive extrapolation would have source of external clouds. While only a "handful" of galaxies showing the ISM totally depleted. With less gas evidence for outflows have so far been available to form stars, this alters our view

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No 69 AIP, New York (1981)., star formation rates are not constant and 13. Koo, B.-C., Heiles, C., and Reach, G. Ahrens er a i., Nucl. Phys. A390, 486 (1982)., K. Elscncr et a l., Phys. Lett 117B 167 (1982)., may even undergo cycles of bursts, some W.T. 1991, in The Interstellar E.G. Adelberger era/., Phys. Rev. C272833 (1983)., researchers have suggested that the ISM Disk-Halo Connection in Galaxies, I A U S ym p. 144, ed. H. Bloemen E.D. Eartc et at. Nucl. Phys. A396 . 221 (1983).. must be continually supplied by some (as K. Elscncr ct a]., Riys. Rev. Lett. 52 1476 (1984)., (Dordrecht, Kluwer), 165 yet hypothetical) source of external H. C. Evans et a t.. Phys. Rev. Lett 55 791 (1985)., accretion, for example primordial material M . B in i et al. Phys. Rev. Lett. 55 795 (1985)., 14. Larson, R.B., Tinsley B. M., and left over from the epoch of galaxy R. W ilson etal. in The Investigation o f Fundamental Caldwell, C.N. 1980, Ap. J., 237, Interactions with Cold Neutrons, ed., G.L. Greene, formation (Pfenniger and Combes 1994; 692 Pfenniger, Combes and Martinet 1994). NBS Special Pub. No. 711, NBS. Washington (1986). Thus, a better understanding of the [9] A.B. McDonald et at., in. Rep. on Res. in Nucl. Phys. long-term effects of gas consumption and 15. McKee, C.F., and Ostriker, J.P. 1 977, at Queen's £/niv(1985). mass loss are required in order to address Ap. J., 218, 148 concerns of a cosmological nature. [ 10] V.P. Alfimenkov eta l., Nud. Phys. A398 93 (1983); 16. Norman, C., and Ikeuchi, S. 1989, V.P. Afimenkov, Usp. Fiz. Nauk 144 361 (1984) (f gas is being dr íven into int ergalactic space, Ap. J., 345, 372 [Sov. Phys. Usp. 27 797 (1984);] ; Y. Mu su da il ct it is also of interest to consider what effects a| el at.. Nucl. Phys. A504, 269 (1989).; C D. such outflows will have on the galaxian 17. Oka, T., Hasegawa, T., Handa, T., Bowman, J.D. Bowman, and V.W . Yuan, Phys. Rev. environment. Will these outflows Sato, F., and Tsuboi, M. 1 995, in CO: C 39 1721 (1989). dynamically affect their nearby neighbours, Twenty-live Years ot.Millimeter-wave Spectroscopy, !A USymp. 170, in press [Il] J.D. Bowman eta l.. Phys. Rev. Lett, 65, 1192(1990); as suggested by observations of a C.M. Frankie eta l., Phys. Rev. Lett. 67 564 (1991). companion to thegalaxy, NGC 3079 (Irwin 18. Pfenniger, D., and Combes, F. 1994, et al. 1987)? To what extent do these [ 12] J.B. French eta !.. Ann. Phys (N.Y.) 181 260(1988); Astr. Ap., 285, 94 outflows enrich the intergalactic medium S. Tomsovic, I1i.D. Thesis, University of Rochester (1987). with heavy elements from supernova 19. Pfenniger, D., Combes, F., and ejecta? Is this a source of hot intergalactic Martinet, L. 1 994, Astr. Ap., 285, 79 gas which is observed in some clusters of [13] S. Tomsovic. Unpublished. galaxies? Does this gas contribute to the 20. Rand, R.J., and Stone, J.M. 1995, [ 14] M.B. Johnson eta l., Phys. Rev. Lett. 67, 310(1991). intergalactic absorption lines (mostly Lyix) A. J. in press seen against background quasars (and [15] K. Neubeck e ta l, Phys. Rev. CIO, 320 (1974). closer objects)? The implications of such 21. Reach, W.T., Heiles, C., and Koo, activity are only now being explored. It B. -C. 1993, in Back to (he Galaxy, [ 16] B.A. Brown. W. A. Richter, and N.S. Godin, Phys. seems likely, however, that our view of AIP Coni. Proc. 278, ed. S.S. Holt Rev. Lett. 45 1681 (980). spiralgalaxiesas the isolated stellar systems and F. Verter (New York, AIP), 548 which grace the covers of textbooks may [17] F.C. M ichd, Phys. Rev. 133. B329 (1964). require substantial modification. 22. Shapiro, P.R., and Field, G.B. 1976, Ap. J., 205, 762 [ 18] A.C. Hayes and I.S. Towner, Phys. Lett. B 302, 57 (1993) . ACKNOWLEDGEMENTS 23. Sorathia, B., 1994, M.Sc. Thesis, [19] P. Hcrczcg, Uyperfinc Interact. 75, 127 (1992). I would like to thank Dr. Nancy Evans for Queen's University suggesting this article. The author's [20] W.C. Haxlon and E.M. Henley, Phys. Rev. Lett. 51, 24. Tenorio-Tagle, G., and Bodenheimer, research is supported through a Natural 1973 (1983). Sciences and Engineering Research Council P. 1988, Ann. Rev. Astr., Ap. 26, of Canada Grant No. WFA01 56373. 145 [21] t.S. Towner and A.C. Hayes, Phyta. Rev. C 49,2391 (1994) . REFERENCES 25. Tomisaka, K. 1 991, in The Interstellar Disk-Halo Connection in Galaxies, IAU [22] A. Griffiths and P. Vogel. Phys. Rev. C 43 . 2844 1. Bloemen, H.. ed. 1991, The Interstellar Symp. 144, ed. H. Bloemen (1991). Disk-Halo Connection in Galaxies, I A U (Dordrecht, Kluwer), 407 Symp. 144 , ed. H. Bloemen [23] J.D. Bowman e ta l., in Fundamental Symmetries In (Dordrecht, Kluwer) 26. Völk, H. J. 1991, in The Interstellar Nuclei and Particles, ed. by H. Henrikson and P. Disk-Halo Connection in Galaxies, IAU Vogel (World Scientific, Singapore 1990), p. I. 2. Bregman, J.N., and Pildis, R.A. 1994, Symp. 144, ed. H. Bloemen Ap. J., 420, 570 (Dordrecht, Kluwer), 345 [24] M. Siinonious, Phys. Lelt, B58, 147 (1975).

[25] W. C. Haxlon, A. Holing, and M. Musolf, Phys. Rev. 3. Cox, D.T., and Smith,B. W. 1 974, Ap. 27. Waller. W.H., and Boulanger, F. 1 993, J. (Letters), 189, LI 05 in Back to the Galaxy, A IP Coni. Proc. D 50, 3422 (1994). 278, ed. S.S. Holt and F. Verter (New [26] J. Engd.C.R , Gould and V. Hnizdo, Phys. Rev. Lett 4. Fabbiano, G., Heckman, T., and Keel, York, AIP), 544 W. C. 1 990, Ap. J., 355, 442 73 . 3508 (1994).

La Physique au Canada mars à avril 1996 89 Ill-V SEMICONDUCTOR CHARACTERIZATION FOR OPTOELECTRONICS

by Carla J. Miner, Advanced Technology Laboratory, Bell Northern Research, Ottawa, Ontario K1Y 4H7, (e-mail: [email protected])

ABSTRACT assay tools, such as energy dispersive x- right. For example, the multiplication layer ray analysis, have accuracy quoted to the of an avalanche photodiode is several Three of the specialized non-destructive nearest 0.005. Even the most accurate microns thick. To control the breakdown characterization tools developed to monitor methods have difficulty with the small voltage of such a device the thickness of the advanced materials used in the sampling volumes (spot size a few this layer must be known to better than fabrication of high speed optoelectronics millimeter in diameter, layers less than 5 2%. The waveguide layers of a laser are are described, namely, scanning micrometers thick). Therefore, knowledge more difficult still, in that they are only a reflectance spectroscopy (sRS), scanning of the absolute composition is given up in couple of hundred nanometers thick. The photolum inescence (sPL) and double favour of more precise relative composition relative thickness tolerances are the same, crystal x-ray diffraction mapping (DCDM). indicators. For this quaternary alloy, a plus the index of refraction must also be Applications of these tools to the non­ convenient compromise is to measure the tightly controlled. The extreme case occurs destructive assessment of lll-V bandgap energy and the lattice constant of in those devices where the active layer is semiconductor composition, layer the material, which both vary in a series of quantum wells, each only a thickness and defect density are predictable ways with x and y. Only one handful of atomic layers thick. While illustrated. composition will have a specific thickness control is made somewhat easier combination of both bandgap energy and since quantum wells only come in integer INTRODUCTION lattice constant. number of atomic layers (monolayers) While silicon, an elemental semiconductor thick, measuring the thickness of these from the fourth column of the periodic The bandgap energy is the separation thin layers requires innovative solutions. table, is the building block of today's between the highest ground state and the Optical methods have been developed that electronics industry, semiconductor alloys lowest excited state of the valence fill most of these needs. with equal numbers of atoms from the electrons in the semiconductor. Stimulated third and fifth columns are playing a small de-excitation of electrons across the The third major property that needs to be but increasing role. Unlike silicon, these so- bandgap creates the lasing photons the measured and controlled for successful called Ill-V compound semiconductors device designer is aiming for. Since the device fabrication is concentration of the readily emit light under electrical bandgap energy defines the laser impurities added deliberately to change the stimulation and so find use in a range of wavelength and similar properties critical conductivity of the layers. The optoelectronic applications from high to other devices, knowledge of the concentrations of these dopants that make efficiency solar cells to the LED panel bandgap is more important to the difference between acceptable and lights found on most pieces of high tech optoelectronics design than knowledge of unusable material can be on the order of gear to the laser that reads your compact the composition which controls it. Luckily, 10'6 cm 3 or a ppb. At present, few non­ discs. They also typically have a higher bandgap energy is much easier to measure destructive methods exist for measuring intrinsic resistance and a higher electron precisely using the optical methods the dopant concentration quantitatively, velocity than silicon and so are favoured described in the following sections. particularly in complex device structures. for the high frequency analog and high Those that partially fill the need are beyond speed digital electronics in such items as In an analogous fashion, the lattice the scope of this review'. satellite broadcast receivers, cellular constant is also a more critical property for phones and supercomputers. Device optoelectronic applications than the The final item to be found on the list of composition it depends upon. The lattice designers tailor the properties of the critical properties for optoelectronic device semiconductor compound for each constant is the fundamental repeat manufacture is defect density. Defects, at distance of the crystal lattice, typically 0.5 application by using more than one group the most basic level, are misplaced atoms: to 0.6 nm. In the first step in the III or group V element in carefully departures from the expected translation fabrication of a working device, controlled ratios, while maintaining the symmetry of the lattice or the semiconductors layers are grown on a overall stoichiometry. To take advantage incorporation of an unintended impurity single crystal substrate epitaxially, i.e. in of the alloy's unique properties, it is atom. The more serious crystal defects such a way that the atoms in the layers frequently necessary to use a series of thin must be avoided because they make the line up with those in the substrate. If the layers of different composition grown on wafer more likely to break during handling. lattice constant of the alloy is intrinsically They can be detected by x-ray diffraction top of a single crystal substrate. The larger or smaller than that of the substrate, thinnest of these layers can be only a small methods as described later. Both crystal then the crystal must distort tetragonally in defects and impurities are important number of atomic layers thick. This article order to match up in the plane of the describes some of the challenges inherent because they are often associated with growth interface. The distortion builds in electronic states which change the in using Ill-V compound semiconductors in strain. If the strain becomes too high, device fabrication and some of the concentration of free carriers and thereby dislocations and other crystal defects are alter the operating characteristics of the methods that have been developed to formed which ultimately degrade device monitor and help control their properties. device. Techniques that probe the performance. Some of the more advanced recombination of injected carriers are very designs deliberately build in small amounts Consider the set of quaternary Ill-V alloys: effective monitors of the electrically active of strain to modify the electronic band defect density as will be shown. ln„Ga, xAsvP, v. These alloys are essential structure of the material in advantageous to today's fiber optic telecommunications ways. The thickness of the strained Over the past seven years, a number of systems, being used to make the material must be kept low so that the total scanning techniques have been developed necessary lasers, detectors and high speed strain energy is insufficient to induce in the Advanced Technology Laboratory at signal processing circuits. By changing the defect formation. For high performance Bell Northern Research to meet the ratio of indium to gallium and arsenic to devices with good reliability it is necessary demand for rapid, nondestructive phosphorous, an alloy can be selected with to control the relaxed lattice constant of assessment of the substrates and epitaxial a specific combination of properties. The the layer relative to that of the substrate to layers used in the optoelectronic and high first challenge is to get the right ratios. If better than one part in 103. The x-ray speed electronic device manufacturing of the systems design calls for a laser that diffraction methods that are described in its parent company, Nortel. Three of the emits at 1557 ± 5 nm, one of the this article are used to detect minute techniques will be discussed: scanning preferred wavelengths for silica based fiber differences between the lattice constant of reflectance spectroscopy (sRS), scanning optics, the composition of the light the epitaxial layer and the substrate. photo-luminescence (sPL) and double emitting active layer, as described by the crystal x-ray diffraction mapping (DCDM). indium and arsenic mole fractions, x and y, The second challenge inherent in using The measurements are currently being must controlled to within ± 0.003. Ill-V compound semiconductors in device performed by instruments designed and Unfortunately, most of the traditional fabrication is to get the layer thicknesses

90 Physics in Canada March/April I 996 built for us by Waterloo Scientific, of The spectra tell us the thickness of the BANDGAP ENERGY AND DEFECT MAPPING Waterloo, Ontario. layers at fixed points. To map the BY SCANNING PHOTOLUMINESCENCE thickness variation by taking spectra at THICKNESS BY SCANNING REFLECTANCE many points on the wafer is time A convenient method for measuring the SPECTROSCOPY: consuming and, luckily, unnecessary. If the bandgap energy of a semiconductor is photoluminescence spectroscopy6. In monitoring wavelength is fixed and the Scanning reflectance spectroscopy2 makes photoluminescence, a low power laser is wafer scanned under the beam, then any use of optical interference to infer the variation in the product of index and used to excite a ground state electron into thickness of an epitaxial layer and map its the band of excited states. The electron thickness will appear as a change in distribution across the wafer. In sRS, the rapidly loses energy to lattice vibrations reflectance. An example of such a relative intensity of infrared light reflected until it reaches the lowest unoccupied reflectance map is shown in Figure 2a. at normal incidence from the sample is Since the change in index of refraction excited state. It then drops back to the measured as a function of wavelength and uppermost empty level in the band of across the wafer due to variation in position. If the index of refraction of the ground states, giving up the excess energy composition or other factors is usually a top layer is sufficiently different from that in the form of a photon with energy hundred times or more smaller than the of the material beneath it, then the total roughly equal to the bandgap energy. The variation in epitaxial layer thickness, reflected light will be modified by difference between the energy of the contours of equal reflectance correspond constructive and destructive interference emitted photon and the true bandgap is very well to lines of equal layer between light reflected at the top and very nearly kT, being simply related to how thicknesses. To convert the reflectance bottom surfaces of the layer. The many of the states are already occupied by map into a thickness map, it is necessary reflectance spectrum for a 3.0 μτη thick thermally excited carriers. The spectra at to identify the thickness associated with layer of InP grown on a marker layer of room temperature are broad in comparison each contour. The problem is not quite as ln,,aGa47As is shown in Figure 1. The to those familiar to atomic fluorescence daunting as it may seem. If one calculates amplitude of the modulation is determined spectroscopists, but are more than the thickness of the layer for one point on by the difference in the indices of adequate to allow detailed maps of each adjacent extrema on the map, it is refraction of the layer and the material bandgap variation to be constructed. possible to accurately interpolate the below it; in this example the difference is thicknesses for the contours between 0.36 (~ 10%). The spacing of the extrema is Figure 3 is a scanning photoluminescence them. Figure 2b shows the resultant related to the product of the thickness and map of the bandgap energy distribution for inferred thickness map. The pattern seen in index of refraction of the top layer. Thinner a ln„Ga, „AsyP, y layer grown on InP. The Figure 2 is a result of gas flow patterns in layers have more widely spaced extrema. 7,000 point map took 16 hours to acquire. the metal organic chemical vapour Since the indices of refraction of the The total range of the data is 40 meV, deposition (MOCVD) system used to In,Ga, „AsvP, v alloys are known to better corresponding to a standard deviation in deposit the layers. There are 41,000 valid than 1 part in 300 and the extrema peak wavelength of 9 nm for the central data points on this map. Data acquisition positions can be determined from such a 90% of the wafer. For a laser with a and analysis took only 45 minutes. Very spectrum to an accuracy of 1 part in wavelength tolerance only 10 nm wide, few other analytical methods provide this 1000, the thickness of the layer can be this implies that only a maximum of 45% speed, resolution and accuracy non­ readily determined with an overall accuracy of the devices made from this wafer will destructive^. of better than 0.3%. be within specification. Notice that the pattern in Figure 3 is reminiscent to the thickness distribution seen in Figure 2. The gas vortices in the MOCVD chamber that lead to enhanced growth rate in the kidney shaped central region also lead to composition variation and thus bandgap energy shifts. This is confirmed when the sPL data is analyzed in conjunction with the x-ray diffraction data discussed in a later section.

Wavelength (nm) Fig. 2a The reflectance at a wavelength of 1000 nm is displayed for an InP layer Fig. 1 Normalized reflectance plotted as a grown on an ln 53Ga47As marker layer. function of wavelength for a 3 μτη The red and blue fringes correspond to thick layer of InP on a 3.5 μτη thick thicknesses of InP with reflectance layer of In i3Ga 47As. The reflected light extrema at the map wavelength. The spectrum of a bare InP substrate is InP substrate diameter is 50 mm. used to normalize the data and thereby reduce system artifacts.

The thinnest layer that can be practically measured by reflectance spectroscopy has only one complete period in the spectral Fig- 3: The peak energy of the range covered by a single light source - photoluminescence emission is mapped detector pair. For the range shown in for a ln„Ga1xAsyP1y layer deposited by Figure 1, which corresponds to an InGaAs MOCVD. As in Figure 2, the gas flow detector and a tungsten lamp, the thinnest direction is top to bottom. The InP measurable InP layer is ~ 300 nm thick. For wafer diameter is 50 mm. thinner layers, measurements based on the polarization dependence of reflection, such A novel application of bandgap energy as ellipsometry3, are more appropriate. mapping by sPL allow s the measurement Multi-layer structures have more complex of the thickness of quantum wells6. One of Fig. b: With the additional information inferred spectra, which may be thought of as the from at least one reflectance spectrum the most dramatic effect of reducing the superposition of the reflectance spectra of for each fringe, the sRS map can be thickness of an epitaxial layer to below the each individual layer. They can be analyzed translated to this thickness map. The quantum limit (20-30 nm) is a rapid by iterative fitting to theoretical curves or characteristic pattern is due to the flow increase in bandgap energy. As can be of reactants in the deposition chamber by using a modified Fourier approach4. which enter at the top of this image. shown with simple particle-in-a-box models, which are surprisingly good

La Physique au Canada mars à avril 1996 91 approximations to the observed data, the had not been properly cleaned from the In Figure 6 the peak full width at half increase is inversely proportional to the wafer prior to epitaxial layer growth. It is maximum (fwhm) map of an average well thickness squared. Therefore if the not uncommon to find with sPL that quality 76 mm diameter GaAs substrate is composition of the well doesn't vary, maps contamination spreads many millimeters displayed. It was obtained by measuring of quantum well sPL energy can be directly away from its point of origin. Other rocking curves in a matrix of x-y points on interpreted in terms of variations in well sources of epitaxial layer defects have a 750 //m grid over a 8 hour period. There thickness. When ternary or quaternary been found by this sensitive method, are many high fwhm features, alloys are used as the well material, sPL including: substrate defects, residues of predominantly at the wafer periphery, but energy data can still be used to map the cleaning chemicals and impurities in the also running diagonally across the wafer. w ell thickness as long as the structure gases used for growth. In many instances, From the peak angle maps acquired at the includes a reference layer of the same the concentration of the impurities which same time, one can identify these nominal composition and of a thickness in have a dramatic effect on sPL intensity and elongated features as low angle grain excess of the quantum limit. Then the aspects of device performance7 was found boundaries where the lattice planes tilt by energy shifts due to composition variation to be at or below the detection limit of 10 to 30” with respect to one another. At (w hich show up in both maps) can be traditional impurity analysis methods (i.e. those positions the rocking curves broaden separated from those due to growth rate below 10,ecm 3). or even split since the x-ray beam variation (which only show up in the straddles the boundary. When the quantum well map). An example of a misorientation across these features is nominally 14 monolayer (8.2 nm) thick very large ( > 5 0 ” ), the mechanical strength ln63Ga47As quantum well grown by of the wafer is compromised. Batches of MOCVD is shown in Figure 4. Clearly substrates can be screened this way to defined regions appear with distinct energy eliminate those most likely to break. shifts. The assignment of the bands to a specific number of monolayers is made on the basis of comparison to theory or a one time calibration with a destructive analysis method such as transmission electron microscopy. The quantum well thickness pattern is similar to that found by sRS for thicker layers.

Fig. 5 The photoluminescence intensity at a fixed wavelength is mapped for a MOCVD grown Ιη^β,.,Ας,Ρ, „layer. The sPL intensity is strongly reduced in the vicinity of particulates which were inadvertently introduced prior to Fig. 6 The DCD fwhm is mapped for a growth. The InP wafer diameter is commercial grade semi-insulating GaAs 50 mm. wafer grown by liquid encapsulated Czochralski. The regions of higher than DEFECT AND LATTICE CONSTANT normal fwhm correspond to low angle MAPPING BY DOUBLE CRYSTAL X-RAY grain boundaries or other crystal defects. The wafer diameter is 76 mm. DIFFRACTION

Fig. 4 The quantum energy shift is mapped The crystal perfection of the sample is DCDM is an important tool for the by subtracting the observed most easily assessed by x-ray diffraction. evaluation of epitaxial layers. When there photoluminescence peak energy of a If the interatomic plane spacing, the are two different crystal plane spacings ln 53Ga 4?A s quantum well from that of wavelength of the x-rays and the angle of within the x-ray sampling volume (e.g. a a thick lnMG a4,As reference layer incidence with respect to the crystal not too thick, slightly mismatched layer on grown beneath it. Each band of planes satisfy the well known Bragg a substrate), the diffraction condition is distinct energy is assigned to a specific diffraction condition, the x-rays diffract satisfied at two different angles. The DCD number of monolayers based on a rocking curve then shows two distinct separate calibration. The layers were strongly from a single crystal sample. If peaks, whose separation is linearly related grown by MOCVD on a 76 mm there is any local deviation in the sample diameter InP wafer . crystal plane orientation or spacing, the to lattice strain. Device engineers can diffraction condition will not be satisfied examine DCDM peak separation maps and The intensity of the emitted and the detected x-ray intensity falls. decide whether the strain is within photoluminescence is a function of the Double crystal diffraction8 is a variant of acceptable tolerances. Alternatively, excitation rate and the rate at which the the classical method in which diffraction DCDM peak separation maps can be used electron de-excite through alternative from a first crystal is used to reduce the to determine ternary alloy composition. paths that do not involve the emission of a divergence of the x-ray beam before it is The peak separation observed for an near bandgap photon. Surface states or diffracted from the test wafer. The AI„Ga, „As layer grown by molecular beam mid-bandgap defect states frequently act measurement consists of monitoring the epitaxy (MBE) on GaAs is shown in Figure as non-radiative de-excitation paths. If the diffracted x-ray intensity as the sample is 7. The uniformity is quite good: the excitation power is not so high that the rocked through the optimal angle. The inferred composition is x = .304 ± .005. density of photo-excited electrons exceeds peak angle, intensity and the full width half However the DCD map shows an edge-to- the density of non-radiative centers, than maximum of the rocking curve are center variation that goes counter to any decrease in sPL intensity is directly recorded. Although the actual angle expectations based upon flux distributions related to the density of defects. Figure 5 corresponding to the peak intensity has observed in the growth chamber. The shows an interesting example of a sPL limited meaning due to uncertainty in the central portion of the wafer has a higher intensity map measured under low instrument's true zero position, relative than expected peak separation, excitation conditions. The wavelength was angle changes can be mapped with arc corresponding to ~ 1 % more aluminum in the fixed to be near the peak of the sPL second precision and are used to quantify alloy. The root cause was traced down to spectrum and the wafer was stepped long range lattice curvature and the interactions with the substrate holder in 200 //m on center to build up a high spatial angular deviation across low angle grain the growth chamber. Due to the placement resolution map. The 48,000 point map boundaries8. This method is of the substrate heater and the high took 35 minutes to acquire. At the cores complementary to the higher spatial thermal conductivity of the holder, the of the conspicuous low sPL intensity resolution topography methods where the holder is generally cooler than the wafer. regions were tiny specks of dust which wafer is imaged for a fixed rock angle'0. Depending on the degree of thermal contact between the wafer and the holder,

92 Physics in Canada March/April 1996 the center of the wafer can be up to 15°C which has led to many unexpected hotter than the edge. Unfortunately, at the discoveries about sources of non­ temperatures preferred for the growth of reproducibility and non-uniformity. Without high quality AI.Ga, „As, a significant the insights that sRS, sPL and DCDM have proportion of the gallium atoms striking the provided, the job of developing advanced wafer surface re-evaporate. In the hot optoelectronics would have been much central zone even more gallium evaporates, more difficult. locally enhancing the aluminum mole fraction. By redesigning the holder, this effect can be minimized. REFERENCES

1. For example: C.J. Miner, Semiconductor Characterization: Present Status and Cette Future Challenges, ed. W.M. Bullis, D.G. Seiler and A.C. Diebold (AIP, Revue Woodbury, N.Y., 1995) 605, and other papers in the same volume. est disponible

. L.E. Tarof, C.J. Miner and C. Blaauw, sur microfilm ou J. Appl. Phys., 68 (1990) 2927. microfiche

3. H. Tompkins, A User's Guide to Fig. 7 The DCD peak separation is displayed for a AI 3Ga ,As layer grown by MBE on EHipsometry, Academic Press, 1 993. Les volumes antérieurs de GaAs. The central area of larger absolute peak separation was caused cette publication sont by enhanced gallium desorption during 4. P.L. Swart and B.M. Lacquet, J. Appl. growth at a local hot spot. The wafer également disponibles Phys., 70 (1991) 1069. diameter is 7β mm. sur microfilm ou For quaternary alloys, sPL peak energy michrofiche. data and DCDM must be combined to infer 5. C.J. Miner, Semicond. Sci. Tech., 7 both the group III and group V mole (1992) A10. fractions. With this data, for instance, it is possible to show that the downward energy shift shown in Figure 3 and the 6. N. Puetz, G. Hillier, C.J. Miner and enhanced quantum w e ll gro w th rate show n A.J. Spring Thorpe, Crystal, Properties in Figure 4 are the consequence of enhanced arsenic incorporation (y and Preparations, 32-34 (1991) 514. Pour de plus amples increases by 0.01 5). The ratio of indium to gallium in the ln „G a ,„A syP,.y layers is renseignements, i x’uillcz largely unchanged across the wafer. 7 C.J. Miner, D.G. Knight, B. Watt, Modifications to the growth chamber C. Blaauw and N. Puetz, IFFELFOS'90 communiquer avec : geometry and the use of substrate rotation Conference Proceedings (1990) 615. reduce the non-uniformity by a factor of 2. In this way, the tight specifications on laser wavelength and lattice strain imposed 8 I.C. Bassignana, C.J. Miner and by the application can be met. N. Puetz, J. Appl. Phys., 65 (1989) SUMMARY 4299. The techniques described here have proven IL· to be essential to the development of the 9 C.J. Miner, Proc. Semi-Insulating lll-V lll-V compound semiconductors for a Micromedia variety of optoelectronic applications. They Materials Conference, Warsaw, Poland, have demonstrated the required accuracy ed. M.Godlewski (World Scientific Limited and precision to monitor several of the key Press, Singapore, 1994) 87. properties. They provide rapid feedback, so Canada's Information that it is possible to quickly adjust growth People conditions to hit tight specifications. They 10. I.C. Bassignana and D.A. Macquistan, Proc. are a definite improvement on the Semi-Insulating lll-V Materials Conference, traditional approaches of growing Ixtapa, Mexico, ed. C J. Miner, W. Ford and 20 l ictoria Street. calibration wafers for destructive analysis Toronto, Ontario M5C 2X8 of a small number of selected points, or E.R. Weber (I0P Püüishng. Bristol, 1993) waiting until the devices are fabricated and 183. (416)362-5211 tested (typically 3-6 weeks). These new 1-800-387-2689 techniques have been optimized for speed, to make high spatial resolution mapping 11. C.J. Miner, B. Watt, W.T. Moore, practical. By studying the pattern of the A. Majeed and A.J. Spring Thorpe, properties measured on the wafer, it is J. Vac. Sci. Tech., B11 (1993) 998. frequently obvious why the variations have occurred and what measures should be taken to correct them. Because these tests are non-destructive, there is little reluctance on the part of manufacturing engineers to monitor frequently, a practice

La Physique au Canada mars à avril 1996 93 THE EARLY HISTORY OF WOMEN IN UNIVERSITY PHYSICS: A TORONTO CASE STUDY

by Alison Prentice Professor of History, Ontario Institute for Studies in Education

One often finds, in discussions of women newspaper obituary later described it, for In short order, other women followed Vivian in the sciences, references to women's a "he" not a "she."2 Undaunted, Elizabeth Pound into doctoral studies in physics at presence in "non-traditional" areas of Laird took a teaching post at the Toronto. Their heyday came in the 1920s study. The implication is usually that prestigious Ontario Ladies College at and early 30s. Between 1926 and 1933, six "traditionally" women were not to be Whitby.3 Within two years, a local women were awarded Ph.Ds in physics: found in the sciences generally, or in newspaper was able to report that "Miss Mattie Levi Rotenberg, Elizabeth Cohen, particular sciences such as physics. There Lizzie R. Laird" was studying physics at Beatrice Reid Deacon, Elizabeth J. Aliin, is little truth in this idea. Bryn Mawr College in Pennsylvania and Florence M. Quinlan, and May Annetts had been granted a Mary Garrett European Smith. Indeed, between 1900, when That women have studied all of the fellowship. This distinguished award, one J.C. McLennan was granted U. of T.'s first sciences and have been involved in of only two handed out annually, entitled Ph.D in physics, and 1933, when five scientific work in all disciplines is its recipient to a year of study in Europe. physics doctorates were awarded, women increasingly demonstrated by a growing Elizabeth's fellowship year must have been constituted nearly one quarter of the 31 literature.' In Australia, as Marjorie especially rewarding, for she worked with winners of this degree at Toronto. This Theobald has shown, science was part of Max Planck in Berlin, just prior to his percentage may have been considerably the "women's studies" curriculum of publication of "the papers that launched higher than the norm. As published women's schools and academies the quantum theory."4 After the granting statistics are by decade, rather than throughout the colonial period. A collection of her doctorate in 1901, Elizabeth Laird cumulative, comparisons cannot be exact. of essays dealing chiefly with modern would teach physics at Mount Holyoke, a But we do know that, in 1930-31, when Europe reveals women at work in the small New England college for women, Canadian women's involvement ingraduate sciences, from the eighteenth century heading the department there from 1903 study appears to have temporarily peaked, when much science was conducted in until 1940. In that year she "retired" to women earned slightly more than one-fifth domestic or semi-domestic settings, to more than a decade of further work, on a of all m aster's degrees granted in all fields in more recent times. A recent collection, volunteer basis, at the University of Canada, but only seven percent of the edited by Marianne Gosztonyi Ainley, Western Ontario, before her second doctorates.9 For women to have been the carries the story to Canada. While none of retirement in 1953.6 recipients of over 20 percent of Toronto's these studies suggests that it was easy for first 31 Ph.Ds in physics must therefore be women to be scientists, the overall That Elizabeth Laird was not alone as an counted a singular achievement. message of involvement is clear. Women early woman undergraduate in physics at Toronto we know from the story of have always been interested in science and The success was shortlived. After 1933 studied it whenever and wherever they Caroline Macdonald, a physics graduate women disappear from the lists of Toronto could manage to do so; and some women, who ultimately made her career as a doctorates in physics, not to reappear for in every period since the eighteenth missionary in Japan. Macdonald, the some time. Their disappearance cannot be century, have reached the highest levels of second woman to graduate in honours attributed entirely to lack of mentorship, for excellence in all areas of scientific mathematics and physics at Toronto, the department, under J.C McLennan and endeavour. That science - even physics - is earned her degree in 1901. Unlike Laird, E.F. Burton, follow ed up its support of a "non-traditional" area for women is Macdonald was offered a graduate women students in physics with the largely false. fellowship. The efforts of J.C. McLennan to persuade her to accept the award were, granting of some teaching appointments. How, then, did the idea develop? The story however, unavailing. Perhaps, as Caroline Even prior to 1920-21, a total of 25 women of women in physics at the University of Macdonald's biographer suggests, she taught for the physics department at Toronto is suggestive. Women appear to foresaw that the path of a woman Toronto, although most were probably have studied physics at Toronto very soon physicist in Canada would be difficult, but master's students and few taught for more after their admission to the university in it is even more likely that "she was already than two or three years. One of these early 1884. By the early decades of the committed in quite another direction." assistants in physics, Annie Theresa Reed twentieth century, women were making After a period working for the YWCA, this (B.A. 1897) was an exception to the rule. their mark in graduate physics and earning talented and dynamic woman moved to The calendars and directories list her as doctorates as well as master's degrees in Japan where she became involved in "Class Assistant in Physics" from as early the field. In the 1940s, the Department of settlement work and eventually in the as 1911 and into the 1930s, but by 1924­ Physics even admitted several women into Japanese labour movement.0 25 she also held the title "Secretary to the the professorial ranks and, shortly after the Physics Department," a role that she had middle of the century, named its first Nevertheless, women eventually did move evidently played for some time. Holding woman full professor. The promise of the into graduate study in physics at Toronto. onto the latter position until 1946, Annie first half of the century was not fulfilled, An examination of the university calendars Reed became not just a fixture, but a force however, in the second half. and directories reveals them,7 as does in the department, remembered fondly for Elizabeth J. Allin’s brief history of the her humour as well as her power.10 The story of Elizabeth Rebecca Laird department. Physics at the University of illustrates the early presence of women in Toronto, 1843-1980.“ Vivian Ellsworth Towards the end of World War I, several undergraduate physics at Toronto. One of Pound was the first woman to earn a women were promoted from assistantships two sisters who gravitated to the study of doctorate in physics at the university, to positions as demonstrators. One of the science (Annie Laird moved from chemistry receiving her degree in 1913. Pound women who began teaching for the to household science and was the head of lectured at Queen's from 1912 to 1917, department at this time (earning her Toronto's household science department when she evidently moved briefly into the doctorate over a decade later) was for 34 years) Elizabeth chose physics after world of business. But she returned to Florence Quinlan. Quinlan was to carve out her matriculation from London Central university science in 1922 when she found a special niche for herself teaching physics Collegiate and graduated from Toronto a position in mathematics at Buffalo. Like to household science and music students with honours in mathematics and physics Elizabeth Laird, Vivian Pound may have at the university and, like Reed, had a long in 1896. But the fact that she "had stood been forced to leave Canada in order to career at Toronto. Nor was she alone, for first for three years running" in her class pursue a career in university teaching and she was soon joined in undergraduate did not win her the coveted fellowship that research. We know from American Men of teaching by another Toronto graduate, would have given her several years of Science |sic| (1961) that she remained at Kathleen Crossley (B.A. 1918). Crossley graduate study abroad; this scholarship Buffalo and was promoted to full professor, never obtained either a master's degree or was designated, as the author of a retiring as Professor Emeritus in 1 955. the doctorate, but nevertheless taught at

94 Physics in Canada March/April 1996 the university for more than three decades, reduction in staff at the New England When Elizabeth Aliin retired from teaching to be "remembered by many generations college, however, and Cohen returned to in 1 972, she had earned the respect of her of first year students" as the instructor Toronto in 1 935. There she worked for the colleagues and been made a full professor. who introduced them to physics." The department in various capacities, but But, by then, she was the only woman third woman who would spend her entire without promotion, until the mid-1950s.17 remaining on faculty in an increasingly career teaching physics at the University While I have discovered no evidence of male department. In the two years, 1971 of Toronto was Elizabeth Aliin, who taught anti semitism working against Elizabeth and '1 2 , the university awarded 50 in various capacities from the mid-1920s, Cohen or Mattie Rotenberg, it is not doctorates in physics. How many of these joining the staff as "Demonstrator and inconceivable that cultural and religious were women is unknown, but I suspect Research Assistant" in 1931, for a career difference played some role in blocking that, in general, the number of women that did not end until she retired in 1972. their advancement, especially in the case doctoral candidates during the post-World of the unmarried Elizabeth Cohen.'8 War II years was not great.24 More Other women taught for the department, significant, perhaps, was the fact that no but none so continuously or for such long As we have seen, among the women who women were recruited to the professoriate periods as Quinlan, Crossley and Aliin, all taught for the physics department, only during the years which Aliin labelled "the of whom also received promotions into the Florence Quinlan, Kathleen Crossley, and years of affluence" between 1948 and professoriate in the early 1940s. The four Elizabeth Aliin made it into the professorial 1969. As she noted in her history of women who perhaps came closest to ranks. Their promotion occurred in 1941­ physics at Toronto, by 1970 the having careers in physics at Toronto were 42, when the exigencies of war may finally department had a professorial staff May Annetts Smith, Beatrice Reid Deacon, have revealed the department's reliance on "numbering between sixty and seventy" Mattie Levi Rotenberg and Elizabeth these women's w ork.'9 As Elizabeth Aliin and the atmosphere had greatly changed.25 Cohen, all women with Toronto Ph.Ds later recalled, all three felt "very lucky" to The small department of less than a dozen from the interwar years. receive appointments as assistant professors that had made Elizabeth Aliin professors - despite their several decades and her colleagues feel so at home in the Continuing with her research and of service in the cases of Quinlan and 1930s that "we felt as if we owned it,"26 demonstrating work after her 1933 Crossley, and the ten years or more that had expanded mightily. But it would appear doctorate, May Annetts gave up any Aliin herself had taught physics at that few women physicists had chance for a position at Toronto when she Toronto.20 In fact, the late 1 930s had been participated in this growth. left for England to be married in 1936.12 trying years, especially for the women The stories of the other three women are physicists. There were eleven men in the Recently, women have made a comeback more ambiguous. All three taught at Toronto physics professoriate at Toronto as graduate students in physics at Toronto for many years after their by 1937, but no woman had yet joined Toronto. There have been, moreover, doctorates, but were never promoted them; indeed the Great Depression was struggles to hire and retain women faculty. beyond the rank of instructor.'3 Beatrice used as an excuse to remove talented The reasons that these struggles have Deacon and Mattie Rotenberg may have married women from the teaching ranks proven so difficult and unproductive are experienced discrimination because they altogether.21 And depression was followed complex and beyond the scope of the were married. During the first half of the by war. During the Second World War, present account. What should be clear twentieth century, elementary and several of Toronto’s male physicists were from this historical sketch of women in the secondary women teachers typically lost seconded to various government and physics department at Toronto, however, their positions on marriage; most women military jobs, leaving huge teaching loads is that physics is far from a "non­ on university faculties were also expected for those who were left behind. Quinlan, traditional” subject for women in Canada. - or asked - to leave when they tied the Crossley, and Aliin did receive their Indeed, during the early decades of marital knot. Vet the University of Toronto assistant professorships, but they certainly Toronto's development as a research was not consistent on this point. The worked very hard for them. Elizabeth Aliin, university, women were very much biologist Norma Ford and the astronomer for example, taught classes as large as five present, demonstrating their talents as Helen Hogg were among several women hundred students, chiefly armed forces both undergraduates and graduate scholars who managed to combine personnel who needed to learn the students in the field. Some were even marriage and teaching at Toronto during rudiments of radar.22 admitted to the teaching ranks although, this period, gaining both permanent with the possible exception of Elizabeth positions and promotions.'4 Deacon and During the immediate post-war years, Aliin, they appear not to have been given Rotenberg, it would appear, were not so physicists at Toronto were anxious to get the same opportunities at Toronto as men. fortunate. I have been able to discover back to the research that had been laid If physics came to be seen as next to nothing about Beatrice Deacon, aside in 1939 and very soon the graduate "traditionally” not a women's subject, this except that she was active in teaching and program doubled in size. But, of the was a development belonging more to the research at Toronto until at least 1947-48 women physicists, only Elizabeth Aliin second, than the first half of the twentieth and was still a member of the Canadian appears to have been involved in graduate century. It appears to have been attitudes Association of Physicists in 1 952. Mattie teaching and research during this period. that developed, and changes in the culture Rotenberg was perhaps a special case, as Part of a team that worked in the area of and conduct of physics that occurred she eventually had many other irons in the spectroscopy, she delivered papers at during the expansionist period after World fire. In addition to her ongoing physics physics society meetings and was among W ar II, that gave rise to the false teaching and her marriage, she gradually those who were instrumental in founding impression that, with rare exceptions, moved into broadcasting for the CBC and the Canadian Association of Professional women were not at home in the subject. became deeply involved in Jewish Physicists (later the Canadian Association education and philanthropy.'6 of Physicists) in the late 1940s. As she We need to know more about women like recalled in interviews in 1991 and 1993, Elizabeth Laird, Elizabeth Aliin, and their It w ould be useful to know more about Elizabeth Aliin wanted to talk to Canadians less well-known female colleagues. What Elizabeth Cohen, the one single woman in about her work. For all her interest in were the forces that made it possible for this group of four women physicists who research that was done elsewhere - and some women to succeed in physics, when seems most likely to have wanted or she had studied at Cambridge with Ernest others - especially in subsequent needed a full-time career in science. Rutherford, among other luminaries - Aliin generations - would find it so difficult? We Cohen's 1929 Toronto doctorate in thought it wrong that Canadian physicists need, especially, to look carefully at how physics was rewarded by a year of study should meet each other chiefly at physics, at Toronto and elsewhere, in Britain (divided between the Universities American conferences. As the secretary of changed during the decades following the the CAP, she worked hard to make the of London and Bristol) and an Second World War, for it was in these instructorship, followed by an assistant organization a success and was proud of decades that the cultures and structures the contribution she made to Canadian professorship at Mount Holyoke during that govern contemporary physics were physics through this work.23 Elizabeth Laird’s last decade as head of largely created. Even this brief appraisal of physics there. Financial problems forced a the blocked careers of many of Toronto's

La Physique au Canada mars à avril 1996 95 early women physicists suggests that we Archives, Elizabeth Laird Papers, " London Although data available for 1945-46 physicist acquainted with the sting of show the percentage of doctorates should not focus on gender alone when granted to women increasing to 11.5 in making these explorations. Considerations prejudice" The London Free Press, 21 April 1967. According to the latter, Laird that year, the statistics by decade of gender may well have been complicated had won the Mulock Scholarship in indicate a general dropping off after by marital status, ethnicity, and religion - Mathematics and Physics in her second 1930-31, in both degrees, with women not to mention race, class and sexual year and the American Association for not reaching these percentages again preference. The records rarely speak the Advancement of Science Scholarship until the 1960s or exceeding them until directly to these issues; nor are we in her third year. The fellowship that she 1970-71. necessarily at ease with them. Thus was denied was the 1851 Exhibition answers to the question of why Elizabeth Scholarship. See also Mount Holyoke 10. University administrative records show Reed earning money typing for the Allin's female colleagues did not manage College Archives, Elizabeth Laird Papers, 'Physicist Receives Honor,” name of department as early as 1906, and in to move up through the ranks, as she did, paper illegible, 29 May 1913. various years prior to 1924-25 there are may always largely elude us. But it is items recording her pay for stenographic •important to ask this question 3. At the time, a number of Ontario and secretarial work. Reed was part of a nevertheless. For an examination of the women's colleges offered courses trend, for it appears to have been during lives of these women physicists alerts us equivalent to the first year of study at a the second and third decades of the 20th to the kinds of constraints that may university. OLC was one of several century that University of Toronto continue to block the advancement of Methodist institutions for young women faculties and departments began to add secretaries to their staff complements, women in university physics in our own which had an affiliation with Victoria College and could prepare its students for often choosing top women graduates for time, as well as to the complexity of the advanced standing at the University of these positions. Professor Dorothy prejudices and fears that prevent us from Toronto. See Johanna Selles-Roney, " ' A Forward was one University of Toronto overcoming them. Realm of Pure Delight': Methodists and scientist who resisted such an offer, Women's Education in Ontario, 1836­ instead moving on to graduate study and We cannot change the past, but we can 1925," (Ed.D Dissertation, University of a research and teaching career. See try to learn from it and, in the case of the Toronto, 1992). Alison Prentice, "Bluestockings, early history of women in physics at the Feminists, or Women Workers? A University of Toronto, there is some reason 4. University of Toronto Archives, Preliminary Look at Women's Newspaper Clippings Collection, A73- Employment at the University of to be encouraged. That women earned 0026/214(10). The first quotation is from Toronto," Journal of the Canadian nearly one quarter of the Ph.D's in physics "A Young Lady's Success: Toronto Historical Association (1991) 243, 250 *1112131415 that were awarded by Toronto in the first Graduate of 1896 Achieves Honour at and 256. For a brief discussion of Annie third of the 20th century is an important American College," unidentified Reed's importance to the department, see fact. Equally important is the fact that newspaper, 16 March 1998; the second Aliin, Physics at the University of several of them, including at least one who is from the 1 969 Owen Sound obituary Toronto, 10. did not have a doctorate, were able to cited in note 2. work in physics at Toronto during the 11. Aliin, Physics at the University of middle years of the century, although their 5. Newspaper clippings cited above. See Toronto, 11. jobs were sometimes insecure and almost also University of Toronto Archives, Clippings Collection, A 73-0026/214(10) 12. University of Toronto Archives, invariably low-paying. Finally, there is the 'Noted Physicist Plans Her Second Newspaper Clippings Collection, A73- encouraging fact that one of them, Retirement," The Globe and Mail June 0026/009(68) Telegram, 6 October Elizabeth Aliin, had a well-recognized and 26, 1 953. Laird's research during the war 1936. May Annetts' student card (UTA, successful career, despite the apparently was chiefly on radar; after the war she A7 3-00261 /009(68) shows her departure less welcoming climate for women worked on "the effect of microwave from England, followed by many more physicists at Toronto during the years that radiation...on biological materials." moves to various Canadian cities, moves follow ed. Previously, she had worked in a variety of which must have made the pursuit of her areas, publishing approximately 30 papers physics career difficult. Alyson King has during the course of her career. One nevertheless discovered one reference to ACKNOWLEDGEMENT official listing, appearing to date from the her in the calendars of McGill, where she I wish to acknowledge the support of the mid-1930s, reveals that the majority of is listed in 1955-56 as a sessional Social Science and Humanities Research those published before 1 935 were in the lecturer in agricultural physics at Council of Canada for the research prestigious journal, Physical Review. The Macdonald College. same account noted that Laird was a reported in this study. I also wish to thank Fellow of both the American Physical 13. Assistants and demonstrators appear to Cathy James, Penny Stephenson, and Society and the American Association for have been the lowest ranked Alyson King for their expert research the Advancement of Science. See clip­ appointments, followed by instructor, assistance in its preparation and the ping entitled "Physics" Mount Holyoke lecturer, and the various professorial journal's anonymous reviewers for their College Archives, Elizabeth R. Laird ranks. Presumably only the professorial helpful comments on an earlier version. Papers. appointments carried tenure.

REFERENCES 6. Margaret Prang, A Heart at Leisure from 14. Both Hogg and Ford were married to Itself: Caroline Macdonald of Japan Toronto professors, as was Mossie May 1. Marjorie R. Theobald, "Women's Studies (Vancouver: University of Vancouver Kirkwood (Professor of English and Dean in Colonial Victoria," Melbourne Studies Press, 1995), especially chapter 1. of Women at University College and, in Education (1989-90); Pnina G. Abir-am Caroline Macdonald stayed in contact later, Trinity). Yet Kirkwood felt some and Dorinda Outram, eds. Uneasy Careers with her physicist friends, however, and discrimination because of her marriage. and Intimate Lives: Women in Science, later years would see her appealing to See Prentice, "Bluestockings," 256-57; 1 789-1 979 (New Brunswick and London: E.F. Burton, Toronto's head of physics Alison Prentice, "Scholarly Passion: Two Rutgers University Press, 1989); from 1932 to 1 948, for assistance in her Women Who Caught It," in Alison Marianne Gosztonyi Ainley, ed. Despite efforts to raise money in Toronto for her Prentice and Marjorie R. Theobald, eds., the Odds: Essays on Canadian Women Japanese mission. Women Who Taught : Perspectives on the and Science (Montreal: Véhicule Press, History of Women and Teaching 1990). For an important monograph 7. University of Toronto Archives, University (Toronto: University of Toronto Press, dealing with the United States, see of Toronto Calendars and Directories. 1991), especially 269-72. Margaret W. Rossiter, Women Scientists Every year was examined up to 1 940-41. in America: Struggles and Strategies to I am grateful for the research assistance 15. University of Toronto Directories; C.A.P. 1 940 (Baltimore and London: The Johns of Penny Stephenson and Cathy James membership list, Physics in Canada, Hopkins University Press, 1982). for this part of the study. Supplement to Volume 8, No. 2 (Winter 1952). I am indebted to Alyson King, 2. University of Toronto Archives, 8. Published by the Physics Department in who searched the directories and other Newspaper Clippings Collection, A73- 1981. records to document the careers of 0026/214(10), "Dr. Elizabeth Laird born Toronto's women Ph.Ds in the 1 940s and here, outstanding physicist," obituary in 9. Alison Prentice, et al, Canadian Women: beyond. an unnamed Owen Sound newspaper, 8 A History (Toronto: Harcourt Brace April 1969, and Mount Holyoke College Jovanovich, 1988) Table A.20, p. 428. (continued on page 100)

96 Physics in Canada March/April 1996 USING NONSEXIST LANGUAGE L'UTILISATION D'UN LANGAGE NON-SEXISTE by Ruth King, York University par Ruth King, York University

Many changes are necessary for women to achieve equality and Il reste plusieurs changements à faire pour que les femmes visibility in society. Considerable research has shown that atteignent l'égalité et la visibilité qui leur revient. Plusieurs language plays an important role in constructing social reality and recherches ont démontré que le langage joue un rôle important that sexist language has negative effects for girls and women. For dans l'établissement de la réalité sociale et qu'un langage sexiste instance, Briere and Lanktree (1983) found that women rated a a des effets néfastes pour les jeunes filles et les femmes. Par career in psychology as more or less attractive in direct proportion exemple, Brière et Lanktree ( 1 983) ont trouvé que les femmes ont to the use of nonsexist or sexist language in the career description. considéré une carrière en psychologie comme étant plus ou moins When gender-exclusive language was used, women were less intéressante selon qu'un langage non-sexiste ou sexiste a été interested in the career. Dayhoff’s 1983 study of evaluations of utilisé dans la description de l'emploi. Les femmes étaient moins women running for political office found that the use of sexist intéressées par la carrière lorsque le texte n'employait que le genre language in the campaign literature resulted in female candidates masculin. En 1 983, l'étude de Dayhoff concernant l'évaluation de being more negatively stereotyped. Crawford and English (1984) candidates à des élections en politique, a démontré que l'utilisation found that women students recall information more efficiently d'un langage sexiste dans la documentation de leurs campagnes when gender-inclusive terms such as people, his/her and he/she faisait en sorte que les candidates étaient stéréotypées plus are used. The scholarly literature, then, shows that the idea that négativement. Crawford et English (1984) ont trouvé que les language use is a trivial matter is incorrect. étudiantes se rappellent plus efficacement de l'information quand une terminologie inclusive, comme personnes, leur, et il/elle, est utilisée. Donc, la littérature nous démontre que l'utilisation d'un langage est importante.

Forms of linguistic sexism include the treatment of male-as-norm Des formes de sexisme linguistique incluent l'utilisation du genre (e.g. Each candidate should include three copies of his résumé with masculin comme norme (e.g. Chaque candidat doit soumettre trois the application), irrelevant reference to gender (e.g. That w o m a n copies de son curriculum vitae avec son application), une référence physicist is really smart), irrelevant reference to physical superflue au sexe (e.g. Cette femme médecin est très intelligente), appearance or to domestic relationship (e.g. Jane Smith, wife of une référence superflue à l'apparence physique ou à la relation the well-known lawyer, Stephen Smith...), and inappropriate forms domestique (e.g. Aline Robert, femme du célèbre avocat, Stéphane of address (e.g. Could you get me a copy of that report, dear?). Robert...), et des formes d'adresse qui ne sont pas appropriées Linguistic sexism goes beyond word choice and what information (e.g. Pourrais-tu me chercher une copie de ce rapport, chérie?). Le is included: for instance, research by Nancy Henley et al (1995) sexisme linguistique n'existe pas seulement dans le choix des mots shows that the use of the passive voice in news media reports of et dans l'information incluse: par exemple, la recherche de Nancy violence against women leads readers to take the violence less Henley etal(1995)indiquequel'utilisationdelavoix passive dans seriously. les rapports médiatiques sur la violence contre les femmes amène les lecteurs à considérer cette violence comme étant moins sérieuse.

Here are some suggestions for using nonsexist language, in writing Voici quelques suggestions pour l'utilisation d'un langage non- and speaking. While I identify some problematic practices and sexiste, en écriture et dans la langue parlée. Quoique j'identifie ici suggest some solutions, I suggest that the reader consult a quelques habitudes problématiques et quelques suggestions, je comprehensive set of guidelines that offers a fuller discussion of vous suggère de consulter un guide complet qui examine plus en the issues. profondeur ce sujet.

(1) Use parallel forms of reference for women and men. For (1) Utiliser des termes de référence parallèle pour les example, do not cite a male scholar by surname only and a woman hommes et les femmes. Par exemple, ne pas citer un scientifique scholar by first name plus surname; do not use a title to refer to or seulement par son nom de famille et une scientifique par son address a male colleague but refer to or address a female coworker prénom avec son nom de famille. Ne pas vous adressez à un by first name. In English, use M r as a title for males and M s as a collègue par son titre en même temps que vous vous adressez à title for females, unless you are certain that a woman prefers a une consoeur par son prénom. En anglais, utiliser M r. comme titre title which indicates marital status (M is s or M rs). pour les hommes et /Vfs.pour les femmes, à moins que vous soyez certain qu'elle préfère un titre qui indique son statut marital (M iss ou M rs.).

(2) In English, avoid so-called masculine generics such as the (2) En anglais, éviter les titres masculins, soi-disant pronoun he (his, etc.) with sex-indefinite antecedents or man and générique, comme le pronom he (his, etc.) avec des antécédents its compounds (except in unambiguous reference to males). In de genre indéfini ou m an (sauf quand c'est une référence non- French, avoid l'h o m m e and /es h o m m e s (except in unambiguous ambigue à un homme). En français, éviter l ’h o m m e et le s h o m m e s reference to males). (toujours sauf si la référence est à un homme).

(3) In French, avoid so-called generic occupational titles (3) En français, éviter les titres d'occupation, soi-disant (a vo ca t, etc.). Use masculine ones when referring to a man and générique, (physicien, avocat, etc.). Utiliser les titres masculins en their feminine equivalent when referring to a women (avocate). référant à un homme, et l'équivalent fém inin en référant à une femme When sex is indefinite, use both (les étudiants et les étudiantes de (physicienne, avocate, etc.). Quand le sexe est indéfini, utiliser les ia première année, les étudiantfejs, etc.) Feminine equivalents for deux (les étudiants et les étudiantes de la première année, les masculine titles follow the regular grammatical rules of the étudiant/e/s, etc.) Les titres féminins suivent les mêmes règles language. Avoid compounds with femme (femme médecin, etc.) grammaticales de la langue que les titres masculins. Eviter les which have the same connotations as English compounds with composés avec le mot femme (femme médecin etc.), qui ont les ia d y or w om an. mêmes connotations que les composés en anglais a ve c la d y ou w om an.

(4) In both French and English, avoid using genuine generics (4) Dans les deux langues, éviter l'utilisation de vraies as if they refer only to males (e.g. Many immigrants come to expressions génériques comme si elles ne référaient qu'aux Canada each year. Their wives have little access to language hommes (On peut utiliser le langage pour beaucoup de raisons - training.; On peut utiliser le langage pour beaucoup de raisons - discuter avec sa femme, par exemple; Many immigrants come to discuter avec sa femme). Canada each year. Their wives have little access to language training).

La Physique au Canada mars à avril 1996 97 (5) In English, avoid adding modifiers or suffixes to nouns (5) En anglais, éviter l'ajout de modificatifs ou de suffixes aux that mark sex unnecessarily (e.g. woman professor, stewardess). noms qui indiquent le sexe de façon superflue (e.g. w om an (In French, the tendency is the opposite; feminine equivalents are professor, stewardess). En français, la tendance est le contraire: preferred.) en général l'équivalent féminin est préféré.

Finally, it is important to bear in mind that sexist ideas dressed up Enfin, il est im portant de rappeler que les idées sexistes enrobées de in nonsexist language remain sexist. For example, using "the paroles non-sexistes demeurent sexistes. Par exemple, en utilisant worker...he or she..." and "the researcher...he or she..." may, in " le physicien ou ta physicienne... U ou elle... et "le/la présidentiel... some cases, be an adequate linguistic solution, but unless U elle..." on trouve une solution adéquate au problème linguistique, women's work and women's needs are discussed in the mais à moins que le travail et les besoins des femmes soit discuté documents concerned, those documents remain sexist. dans ces documents, ces derniers demeurent sexistes.

REFERENCES RÉFÉRENCES 1. Briere, John and Cheryl Lanktree. 1983. "Sex Role Related Effects 1. Briere, John et Cheryl Lanktree, 1983. "Sex Role Related Effecte of of Sex Bias in Language* Sex Roles 9:625-32 Sex Bias in Language" Sex Roles 9, 625-32.

2. Crawford, Mary et Linda English, 1984. "Generic Versus Specific 2. Crawford, Mary and Linda English. 1984. 'Generic Versus Specific Inclusions of Women in Language: Effects on Recall." Journal of Inclusions of Women in Language: Effects on Recall.* Journal of Psycholinguistic Research 13, 373-81. Psycholinguistic Research 13:373-81 3. Dayhoff, Signe, 1983. "Sexist Language and Person Perception: 3. Dayhoff, Signe. 1983. 'Sexist Language and Person Perception: Evaluation of Candidates from Newspaper Articles." Sex Roles 9, Evaluation of Candidates from Newspaper Articles.* Sex Roles 9:527­ 527-38. 38 4. Henley, Nancy, Michelle Miller et Jo Anne Beazley, 1995. ‘ Syntax, 4. Henley, Nancy, Michelle Miller and Jo Anne Beazley. 1995. Semantics and Sexual Violence: Agency and the Passive Voice" 'Syntax, Semantics and Sexual Violence: Agency and the Passive Journal of Language and Social Psychology 14, 60-84. Voice." Journal of Language and Social Psychology 14:60-84

Additional references regarding gender-neutral language Des références additionelle concernant le langage non-sexiste.

Talking Gender - A Guide to Nonsexist Communication, Ruth King, Talking Gender - A Guide to Nonsexist Communication, Ruth King, Copp Clark Pittman Ltd, Toronto, 1991. Copp Clark Pittman Ltd, Toronto, 1991.

Pour un genre à part entière: Guide pour la rédaction de textes Pour un genre à part entière: Guide pour la rédaction de textes non-sexistes. Ministère de l'éducation du Québec, Québec, 1988. non-sexistes. Ministère de l'éducation du Québec, Québec, 1988.

RENDERING THE CAP BY-LAWS GENDER-NEUTRAL

by D. Poirier, INRS-Énergie et Matériaux

Original Text Possible modification Final Version

"An applicant for membership ”An applicant for membership ”An applicant for membership may be admitted as an affiliate if may be admitted as an affiliate if may be admitted as an affiliate if either either the applicant either

(a) he does not fulfil the (a) he or she does not fulfil the (a) does not fulfil the requirements requirements for membership as requirements for membership as for membership as given in given in Section 2 but does given in Section 2 but does Section 2 but does possess a possess a degree of Bachelor of possess a degree of Bachelor of degree of Bachelor of Arts, Arts, Bachelor of Science, or an Arts, Bachelor of Science, or an Bachelor of Science, or an equivalent degree or diploma from equivalent degree or diploma from equivalent degree or diploma from a recognized institution; a recognized institution; a recognized institution;

or or or (b) he holds professional (b) he or she holds professional (b) holds professional membership membership in an association membership in an association in an association acceptable for acceptable for these purposes to acceptable for these purposes to these purposes to the membership the membership committee; the membership committee; com m ittee;

or or or (c) he has such other (c) he or she has such other (c) has such other qualifications qualifications as Council may from qualifications as Council may from as Council may from time to time time to time decide.” time to time decide.” decide.”

”The elected officers of the ”The elected officers of the ”The elected officers of the Association and the Immediate Association and the Immediate Association and the Immediate Past President shall constitute the Past President shall constitute the Past President shall constitute the Executive Committee of the Executive Committee of the Executive Committee of the Council, hereinafter called ”The Council, hereinafter called ”The Council, hereinafter called ”The Executive” . In the event that the Executive” . In the event that the Executive”. An Immediate Past Immediate Past President cannot Immediate Past President cannot President who is unable to serve serve he shall be replaced by the serve he or she shall be replaced shall be replaced by the most most recent Past President by the most recent Past President recent Past President available.” available.” available.”

98 Physics in Canada March/April 1996 "The Executive Secretary or his "The Executive Secretary or his or "The Executive Secretary shall be nominee shall be empowered to her nominee shall be empowered empowered to sign the bank's sign the bank's form of settlement to sign the bank's form of form of settlement and release, and release.” settlement and release." and to delegate this authority.”

"If a Member desires to vote "If a Member desires to vote "A Member desiring to vote proxies, he shall receive a ballot proxies, he or she shall receive a proxies shall receive a ballot on on which the Executive Secretary ballot on which the Executive which the Executive Secretary shall initial the number of proxies Secretary shall initial the number shall initial the number of proxies authorized.” of proxies authorized.” authorized.”

"All nominations whether made by "All nominations whether made by "All nominations whether made by the Nominating Committee or by the Nominating Committee or by the Nominating Committee or by individual members must be individual members must be individual members must be signed by two members signed by two members signed by two members sponsoring the nominee, who by sponsoring the nominee, who by sponsoring the nomination, and his signature agrees to accept the his or her signature agrees to also by the nominee, who thus nomination." accept the nomination.” accepts the nomination."

"Marked ballots must be enclosed "Marked ballots must be enclosed "Marked ballots must be enclosed in a plain unmarked envelope in a plain unmarked envelope in a plain unmarked envelope w hich must be sealed by the w hich must be sealed by the w hich must be sealed by the voting member and returned by voting member and returned by voting member and returned by mail to the Executive Secretary to mail to the Executive Secretary to mail to reach the Executive reach him on or before May reach him or her on or before May Secretary on or before May 3 0 th .” 3 0 th .” 3 0 th .”

LA MODIFICATION DE LA CONSTITUTION DE L'ACP POUR LA RENDRE NON-SEXISTE

par D. Poirier, INRS Énergie-Matériaux

Texte original Modification possible Version finale

"Un candidat peut devenir "Un(e) candidate(e) peut devenir "Toute personne peut devenir membre affilié s’il remplit l’une membre affilié si il/elle remplit membre affilié si elle remplit l'une des conditions suivantes:” l'une des conditions suivantes” des conditions suivantes:”

"Toute demande d’admission doit "Toute demande d'admission doit "Toute demande d'admission doit être faite au secrétaire exécutif à être faite au/à la secrétaire être faite au secrétariat à l'aide de l’aide de la form ule prescrite, ainsi exécutif(ive) à l'aide de la formule la formule prescrite, ainsi qu'il est qu'il est prévu ci-après, et indiquer prescrite, ainsi qu'il est prévu ci- prévu ci-après, et indiquer la la catégorie de membres à laquelle après, et indiquer la catégorie de catégorie de membres à laquelle la le candidat veut appartenir.” membres à laquelle le/la personne veut appartenir." candidat(e) veut appartenir.”

"Après avoir étudié les titres et "Après avoir étudié les titres et "Après avoir étudié les titres et qualités des candidats, le Comité qualités des candidats et qualités de chaque candidat(e), le d'admission doit: candidates, le Comité d'admission Comité d'admission doit: doit:

(a) adm ettre le candidat dans la (a) adm ettre le/la candidat(e) dans (a) lui adm ettre dans la catégorie caté gorie indiquée dans la la catégorie indiquée dans la indiquée dans la demande; demande; demande;

ou ou ou (b) demander au candidat de faire (b) demander au candidat ou (b) lui demander e faire partie partie d'une autre catégorie; candidate de faire partie d'une d'une autre catégorie; autre catégorie;

ou ou ou (c) informer le candidat des autres (c) informer le/la candidat(e) des (c) lui inform er des autres conditions qu'il doit remplir, autres conditions qu'il ou elle doit conditions à remplir, conformément aux dispositions et remplir, conformément aux dis­ conformément aux dispositions et normes énoncées à l'Article III.” positions et normes énoncées à normes énoncées à l'Article III. l'Article III."

Quatre directeurs représentent les Quatre d i re c t e u r s ( t r i c e s ) La direction représentant les diverses catégories de membres, représentent les diverses diverses catégories de membres à savoir: catégories de membres, à savoir: comprend quatre postes, à savoir:

un Directeur des membres élu par unie) Directeur(trice) des membres le poste de Directeur des membres les membres titulaires de élu(e) par les membres titulaires élu par les membres titulairesd e l'Association; de l'Association; l'Association;

La Physique au Canada mars à avril 1996 99 un Directeur des membres affiliés unie) Directeur(trice)des membres le poste de Directeur des membres élu par les membres affiliés de affiliés élu(e) par les membres affiliés élu par les membres affiliés l'Association; affiliés de l'Association; de l'Association;

un Directeur-étudiant élu par les unie) Directeur(trice)-étudiantle) le poste de Directeur-étudiant élu membres étudiants de élu(e) par les membres étudiants par les membres étudiants de l’Association; de l'Association; l'Association;

et et et un Directeur des membres unie) Directeur(trice)des membres le poste de Directeur des membres corporatifs élu par les membres corporatifs élu(e) par les membres corporatifs élu par les membres corporatifs de l'Association." corporatifs de l’Association." corporatifs de l'Association."

"Les mandats du président, du "Les mandats du président ou de la "Les mandats des postes de secrétaire-trésorier honoraire et présidente, du secrétaire-trésorier président, de s.-t.h. et de des quatre directeurs sont d'une honoraire ou de la secrétaire- direction sont d'une année. Le année. Le vice-président élu trésorière et des quatre directeurs vice-président élu ou la vice- succède autom atiquem ent au ou directrices sont d'une année. présidente élue succède vice-président." Le vice-président élu ou la vice automatiquement au vice- présidente élue succède président ou à la vice-présidente." automatiquement au vice- président ou à la vice présidente.

The Early History of Women...by A. Prentice (continued from pg. 96)

1Θ. Rachel Schlesinger, "Volunteers for a Fejer's interviews with Elizabeth 25. Aliin, Physics, chapter 4 and p. 62. Dream," Canadian Jewish Historical Aliin, Toronto, May-June, I993. Not only had no women been hired, Society Journal 1, 1 (Fall 1988) it would also appear that all of Allin's •specially p. 31. Mattie Rotenberg 21. Elizabeth Aliin refers to the pressure female colleagues had either retired was active in Hadassah-Wizo, which on married women to resign in or left the department by the end of is the subject of Schlesinger's articl·. Physics at the University of Tpronto, the 1950s. 25. In a 1991 interview, Professor 1 7. Cohen's career at Mount Holyoke left 26. Author's interview with Elizabeth few traces in the Mount Holyoke Aliin was more forceful in expressing Aliin, May 1991. College Archives, apart from notices her view that bias against married of her appointment and eventual women during the Depression was release from employment. There are used as an excuse to "cut the staff" occasional references to her, and "get rid of the women" at however, in the papers of Mildred Toronto. Author's interview with Allen, her colleague in the physics Elizabeth Aliin, Toronto, May 1991. department at the college. See also University of Toronto Archives, 22. Allin, Physics at Newspaper Clippings Collection, A73-0026/064(17), "National the Univer sity MTF1 Research Report 1930" for a brief of Toronto, SO­ account of her early research. SA, and author’s interview with Infra-Red MTF system at 18. Stephen Speisman documents 'the Elizabeth Aliin, Hugh·* Leiitz, Canada. gradual intensification of anti­ May 1991. MTF measurement time semitism in Ontario" from 1933 into 2 secondsi the early years of World War II - just 23. Author's the period when Elizabeth Cohen and interview with Mattie Rotenberg would have been ElizabethAllin, trying to gain a foothold in physics at May 1991; Toronto. See Speisman, "Antisemitism in Ontario: The Karen Fejer's Twentieth Century," in Alan Davies, interview, ed. Antisemitism in Canada: History May-June and Interpretation (Waterloo: Wilfrid 1993. Laurier Press, 1992) 125-29. See also Irving Abella, "Anti-Semitism in 24. Allin, Physics Canada in the Interwar Years,' in a t t h e The Jews of North America, ed. University of Moses Rischin (Detroit: Wayne State Toronto, University Press, 1987). Appendix 3 ,p. 77. Aliin lists 19. University of Toronto Archives, Newspaper Clippings Collection, the recipients A73-0026/371 (08) Telegram, 13 of doctorates September 1941, "Made Professors by year, but at the University of Toronto." "Mis* only initials K.M. Crossley's work is in are given. To MTF systems for IR and mechanics, hydrostatics and heat; discover the Visible testing Miss E. J. Aliin is an authority on exactnumbers modem developments in physics, of w om en, High-speed low-noise measurement especially spectroscopy and o n · would problems having to do with the need to go the structura of the atom; Miss F. M. User-programmable using Image BASIC Quinlan is in charge of the teaching university of physics to household science and directories, as We can upgrade your existing bench! music students.' See also Aliin, I have been Physics, 34. able to do only for the years HARVARD 20. University of Toronto Archives, Oral prior to 19 4 0 ­ APPARATUS CANADA History Collection, B93-0035, Karen 4 1 . TEL: (514) 335-0792,1-800-361-1905 FAX: (514) 335-3482. 1-800-335-0792 [email protected] 100 Physics in Canada March/April 1996 Physics in Canada / La Physique au Canada Vol. 52, No. 2 1996 March/April mars/avril 1996 Physics and Education La Physique et Veducation

Featuring:

"The CAP 1994 Income Survey" by R.E. Green "Women Physics Faculty in Canada" by J.B. Lagowski and J. McKenna "Women Students in Physics in Canada: A Decade of Progress" by A.C. McMillan and E. Svensson "WES-Women in Engineering and Science: A Canadian Success Story at NRC" by M. D'lorio "The Committee on the Status of Women in Physics of the American Physical Society" by L. Martinez-Miranda Individual and Family Profiles of Women Physicists in Canada Canadian Association of Physicists Association canadienne des physiciens et physiciennes

Institutional Members II Membres institutionels (Physics Departments // Départements de physique)

Acadia University Trent University Bishop's University University of Alberta Brandon University University of British Columbia Brock University University of Calgary Camosun College University of Guelph Carleton University Université Laval CEGEP Beauce-Appalaches University of Lethbridge CEGEP de Chicoutimi University of Manitoba CEGEP Francois-Xavier-Garneau Université de Moncton Collège Jean-de-Brébeuf Université de Montréal Collège Montmorency University of New Brunswick Concordia University University of Northern B.C. University of Ottawa Dalhousie University University of Prince Edward Island École Polytechnique Université du Québec à Chicoutimi Lakehead University Université du Québec à Montréal Laurentian University Université du Québec à Trois-Rivières Le Petit Séminaire de Québec University of Regina McGill University University of Saskatchewan McMaster University Université de Sherbrooke Memorial University of Newfoundland University of Toronto Mount Allison University University of Victoria Okanagan University College University of Waterloo Queen's University University of Western Ontario Royal Military College, Kingston University of Windsor Saint Mary's University University of Winnipeg St. Francis Xavier University Wilfrid Laurier University Simon Fraser University York University

1996 Sustaining Members // Membres de Soutien 1996 (as at 1996 March 31)

A. John Alcock Akira Hirose Roger Philips H.R. Andrews Roger Howard Satti Paddi Reddy J. Brian Atkinson David D. Isaak Beverly E. Robertson C. Bruce Bigham Thomas E. Jackman Lyle P. Robertson Bertram N. Brockhouse Allan E. Jacobs John M. Robson Laurent G. Caron J. Larkin Kerwin Donald W.L. Sprung Allan I. Carswell James D. King Alec T. Stewart Robert L. Clarke Ron M. Lees Boris P. Stoicheff Walter G. Davies Roger A. Lessard Eric C. Svensson Gerald Dolling A. David May John G.V. Taylor Gordon W.F. Drake Jasper S.C. McKee Henry M. Van Driel Earl J. Fjarlie Ann C. McMillan Paul S. Vincett Brian C. Gregory Jean-Louis Meunier Erich Vogt Geoffrey C. Hanna Elizabeth J. Nicol Elmer H. Hara Allan A. Offenberger THE CAP 1994 INCOME SURVEY TABLE la: SALARY INCOME

by Ralph E. Green Year of Lower Upper Retired Member Graduation Number Quartile Median Quartile (k$)

Tables 2a to 2c show the results according to the qualifications of the respondents. There were 1 3 responses with a bachelor's TABLE lb: PENSION INCOME degree, 25 with a master’s degree, and 277 with a doctorate degree. Year of Lower Upper Graduation Number Quartile Median Quartile Tables 3a to 3e cover the areas of current employment. There were 186 responses from the academic sector, 66 from government agencies, 38 from industry, 9 from graduate 25-29 1 students, and 13 from other areas. 30-34 3 52.0 35-39 1 - 40-44 7 52.2 68.0 70.0 Tables 4a to 4f cover the geographic region of employment. 45-49 12 40.5 50.0 58.2 50-54 13 40.0 45.0 51.8 There were 29 responses from the Atlantic Provinces. 70 from 55-59 6 38.5 Quebec, 122 from Ontario, 32 from the Prairie Provinces, 35 60-64 2 - from British Columbia and the Territories, and 21 from outside 65-69 2 - Canada. 25-69 47 40.0 48.0 57.9

Tables 5a and 5b show the results by gender. There were 291 responses from males and 18 from females.

In each table, the medians and quartiles are given from five-year periods, based on the year of graduation with a Bachelor of

Science degree. The final entry in a table covers the entire TABLE lc: CONSULTING INCOME period of that table. The medians are not reported if there are less than three responses in period, to maintain confidentiality of the incomes. The quartiles are reported only if there are Year of Lower Upper seven, or more, responses in a period. Graduation Number Quartile Median Quartile (k$) The CAP wishes to thank all those who responded to the survey request, and welcomes suggestions for improving future 40-44 2 45-49 3 3.0 surveys. 50-54 6 7.5 55-59 5 4.5 60-64 4 4.5 65-69 4 8.5 70-74 4 35.0 75-79 1 - 00-04 3 2.0 85-89 1 - 40-89 33 2.6 6.0 14.4

TABLE Id: SCHOLARSHIP INCOME

Year of Lower Upper Graduation N u m b e r Quartile Median Quarti le ( kS ) (k$> (k$>

75-79 1 80-84 1 - 85-89 7 13.8 15.0 17.6 90-94 41 13.0 16.0 20.0

75-94 50 13.0 15.6 19.2

Histogram of 324 salary responses to the CAP 1994 Income Survey La Physique au Canada mars à avril 1996 103 TABLE 2a: QUALIFICATIONS: BACHELOR’S DEGREE

Year of Lower Upper TABLE 3b: CURRENT EMPLOYMENT: GOVERNMENT Graduation Number Quartile Median Quartile (kS) (k$)

Year of Lower Upper 65-69 1 Graduation Number Quartile Median Quartile 70-74 1 - 75-79 1 - 80-84 1 - 85-89 2 - 45-49 1 90-94 7 3.5 20.0 33.2 55-59 6 94.9 60-64 14 74.0 77.6 80.4 65-94 13 17.0 40.5 58.8 65-69 12 70.8 77.5 84.0 70-74 11 67.5 69.0 71.0 75-79 9 64.2 67.0 71.2 80-84 7 52.5 60.0 62.0 85-89 1 - 90-94 5 46.3

45-94 66 62.0 70.0 79.0

TABLE 2b QUALIFICATIONS: 1MASTER'S DEGREE

Year of Lower Upper Graduation Number Quartil·· Median Quartile ( ks )

50-54 1 TABLE 3c: CURRENT EMPLOYMENT: INDUSTRY 55-59 1 - 65-69 3 71.7 70-74 3 52.0 75-79 7 61.5 67.0 76.5 Year of Lower Upper 80-84 2 - Graduation Number Quartile Median Quartile 85-89 3 46.0 (kS)

50-94 25 40.0 52.0 71.8 40-44 1 50-54 2 - 55-59 1 - 60-64 1 « 65-69 9 73.8 85.0 122.5 70-74 3 82.0 75-79 5 80.0 80-84 6 56.5 85-89 5 46.0 90-94 5 40.0 TABLE 2C: QUALIFICATIONS: DOCTORATE DEGREE 40-94 38 45.0 60.3 85.0

Year of Lower Upper Graduation Number Quartile Median Quartile ( k$ )

40-44 1 45-49 3 75.0 50-54 10 85.0 92.9 96.6 55-59 41 78.8 91.0 99.2 TABLE 3d: CURRENT EMPLOYMENT:: GRADUATE 60-64 52 77.5 82.0 93.0 65-69 45 75.0 82.0 89.2 70-74 35 66.2 70.0 79.5 75-79 25 54.0 62.5 74.2 Year of Lower Upper 80-84 36 43.0 50.0 60.0 Graduation Number Quartile Median Quartile 85-89 16 42.5 48.3 52.0 (kS) 90-94 13 38.6 44.0 47.6

40-94 277 54.0 75.0 86.7 65-69 1 75-79 4 54.8 90-94 4 2.5

65-94 9 2.8 29.0 63.8

TABLE 3a: CURRENT EMPLOYMENT: ACADEMIC

Year of Lower Upper Graduation Number Quartile Median Quartile TABLE 3e: CURRENT EMPLOYMENT: OTHER (k$)

45-49 2 Year of Lower Upper 50-54 9 85.8 93.0 97.4 Graduation Number Quartile Median Quartile 55-59 36 81.5 92.0 98.0 60-64 37 80.0 85.0 95.2 65-69 23 75.0 82.4 93.8 70-74 18 60.0 70.0 76.5 65-69 2 75-79 14 54.0 61.8 74.0 70-74 6 66.1 80-84 25 41.8 50.0 53.5 75-79 1 _ 85-89 11 41.0 46.0 50.8 80-Θ4 1 . 90-94 11 24.8 31.0 41.5 85-89 3 LP O O

45-94 186 53.0 76.0 92.0 65-89 13 50.0 55.0 84.2

104 Physics in Canada March/April 996 TABLE 4a: EMPLOYMENT REGION: ATLANTIC PROVINCES TABLE 4e: EMPLOYMENT REGION: BRITISH COLUMBIA AND TERRITORIES

Year of Lower Upper Year of Lower Upper Graduation Number Quartile Median Quartile Graduation Number Quartile Median Quartile

50-54 2 50-54 2 55-59 5 83 . 0 55-59 8 67.6 92.7 100,0 60-64 8 70.9 75.8 79,2 60-64 6 87 . 8 65-69 5 75.0 65-69 6 76.9 70-74 3 70.0 70-74 2 75-79 3 49.5 75-79 3 67.0 80-84 3 42.0 80-84 5 50.0 85-89 1 _ 50-84 29 61.5 75.0 82.6 90-94 2 - 50-94 35 55.3 74.0 89.2

TABLE 4b; EMPLOYMENT REGION.: QUEBEC

TABLE 4f : EMPLOYMENT REGION: OUTSIDE CANADA Year of Lower Upper Graduation Number Quartile Median Quartile 40-44 1 - (kj) 50-54 1 - 5 90,0 55-59 50-54 60-64 8 81.5 82.0 83.0 2 60-64 4 119.0 65-69 11 71.1 80.0 84 . 0 70-74 13 65.9 75.0 80.5 65-69 2 - 75-79 9 53.5 60.0 72.8 70-74 2 - 80-84 9 48.0 53.0 61.6 75-79 1 - 85-89 8 48,0 51.0 56.5 80-84 3 51.7 48.3 90-94 5 40.0 85-89 4 90-94 3 34,5 40-94 70 52.0 67.5 81.0 50-94 21 46.7 80,0 128.6

TABLE 4c: EMPLOYMENT REGION: ONTARIO TABLE 5a: GENDER: MALE

Year of Lower Upper Graduation Number Quartile Median Quartile Year of Lower Upper

40-94 291 54.0 75,0 86,0

TABLE 4d: EMPLOYMENT REGION: PRAIRIE PROVINCES

Year of Lower Upper TABLE 5b: GENDER: FEMALE Graduation Number Quartile Median Quartile (kS) (k$) (kS) Year of Lower Upper 45-49 1 - Graduation Number Quartile Median Quartile 50-54 3 94.0

45-94 32 48.5 76.1 95.0 65-94 18 34.5 45,0 60.0

La Physique au Canada mars à avril 1996 105 WOMEN PHYSICS FACULTY IN CANADA Summary of Results of a Survey Sponsored by the Canadian Association of Physicists by Jolanta B. Lagowski, Dept of Physics, Memorial University of Newfoundland, St. John's, NFLD, A1B 3X7 and Janis McKenna, Department of Physics, University of British Columbia, Vancouver, BC, V6T 1Z1 INTRODUCTION A recent international studyd) of women in physics showed that the TABLE 1: THE SURVEY MAILED TO CAP PHYSICS INSTITUTIONS. representation of women in physics departments at the faculty level ranges widely - from a high of 47% in 1. Does your institute grant PhD's in physics? Hungary, 23% in France, Italy and Turkey, 6% in the Netherlands and New 2. a. How many students have received a BSc in physics Zealand, to surprisingly low values of from your department from 1993-95? 3% in Korea and the U.S.A. Also, in general, as the educational degree level 2. b. Of these BSc graduates, how many were female? increases, the proportion of women in physics decreases.(2) This phenomenon 3. a. How many students have received a PhD in physics is often referred to in the American from your department from 1993-95? literature as the "leaky pipeline".(2) 3. b. Of these PhD graduates, how many were female? At the 1995 Canadian Association of Physicists (CAP) Congress hosted by 4. a. How many faculty members are presently in Laval University in Quebec, an evening your department? session on Women in Physics was arranged, and among the presentations 4.b. Of these faculty members, how many are female? were results of several surveys of women in physics. Several congress 4.c. How many tenured faculty members are presently participants asked how Canada in your department? compares worldwide with respect to these statistics, as Canada was not 4.d. How many female tenured faculty members are listed in the international comparison presently in your department? studyd). Apparently, statistics have not previously been collected regarding 4,e. How many tenure-track faculty members are the number of women in faculty presently in your department? positions in physics departments in 4.f. How many female tenure-track faculty members are Canadian academic institutions. presently in your department? Sponsored by CAP, a simple survey was distributed in order to estimate the 4. g. If 4f + 4d does not equal 4b, or if 4c + 4e does not equal 4a, please state number of female faculty in Canadian discrepancy. physics departments. This survey was never intended to be as exhaustive as 5. If you have any comments on women in physics issues that you'd like to that performed by the Committee on share with us, please feel free to include any comments. the Status of Women in Physics (CSWP) of The American Physical Information supplied by: ______Society, but it is a first attempt to Position: ______present quantitative data on women Department of Physics, physicists in Canada. A brief summary University: ______of the recent female physics graduates Phone: ______(at the B.Sc. and Ph.D. levels) is also Email: ______given. Fax: ___ THE SURVEY RESULTS AND DISCUSSION Early in the Fall of 1995, the CAP A total of 40 responses to the survey provided to CAP. That is, percentages survey was sent to 63 physics were received in the late Fall of 1995; were tabulated based on the data given departments in colleges, CEGEPs and 25 were from PhD granting institutions, without changes or interpretation (e.g. universities in Canada, including all 54 and 15 from non-PhD granting numbers reported by the respondents CAP member physics departments. The institutions. The survey data' are as "approximate” were treated the CAP survey that was mailed to summarized in Table 2. No attempt same way as the more "accurate" Canadian academic institutions is was made to verify numbers that were numbers). shown in Table 1.

1 Some universities (2) did not supply data for B.Sc. graduates. The faculty total is not equal to the sum of tenured faculty plus tenure-track faculty due to the inclusion of visiting faculty positions, faculty with emeritus status, and part-time faculty positions which respondents listed as faculty, but neither tenured nor tenure-track faculty.

106 Physics in Canada March/April 1996 ______TABLE 2: SUMMARY OF SURVEY RESULTS ON WOMEN IN PHYSICS IN CANADA. (Received From 40 Canadian Academic Institutions and Collected in the Fall of 1995.) All Canadian Physics Departments Total Number of Percentage Number Women Women (Men & Women) B.Sc. Graduatest 1613 284 18 Faculty 707 34 5 Tenured Faculty 621 12 2 Tenure-Track Faculty 76 21 28

t total number of degrees granted in the period 1 993-1 995. Canadian PhD Granting Physics Departments Only Total Number of Percentage Number Women Women (Men & Women) B.Sc. Graduatest 1453 261 18 Ph.D. Graduatest 336 44 13 Faculty 612 27 4 Tenured Faculty 539 8 1.5 Tenure-Track Faculty 65 18 28

t total number of degrees granted in the period 1993-95

The survey results show that in TABLE 3: SUMMARY OF RESULTS FROM AN AMERICAN SURVEY Canada, 18% of all recipients of a B.Sc. SIMILAR TO THE ONE PRESENTED HERE. Degree in Physics, and 13% of all The American Study provided information on faculty rank ifutt, associate, assistant professor), which is recipients of a Ph.D. Degree in Physics approximately equivalent to the tenured and non tenured categories presented in Table 2 in this CAP are female. 5% of all physics faculty study. members and 2% of tenured physics faculty members are women: the "leaky American PhD Granting Physics Departments Only pipeline" trend is present in Canada, in Total Number Percentage fact very similar to the situation Number of Women Women observed by our American colleagues in (Men & Women) their country. Faculty 4746 229 5 The percentage of women faculty at Assoc. & Full Prof. 3584 132 4 non-PhD. granting institutions is Asst. Prof. 592 60 10 somewhat higher (7%) than in the Ph.D. granting institutions (4%). Data are based on information in Reference 3. However, it is encouraging to see that approximately a quarter of all tenure- track faculty positions in the physics TABLE 4: PERCENTAGE OF PHYSICS DEPARTMENTS departments in Canada are currently WITH ONLY ONE OR NO WOMAN FACULTY MEMBER held by women. It should be noted that tenure-track faculty members (of both Number of All Canadian Canadian PhD Canadian non-PhD American gender) constitute only 11% of all Women Physics Granting Physics Granting Physics PhD Granting physics faculty members. Faculty Departments Departments Departments Departments* In Table 3, results from a similar American survey [2] in 1994 are none 45% 38% 60% 36% summarized for comparison with the none or one 80% 72% 93% 69% Canadian survey results presented in Table 2. • Statistics for American Physics Departments are from Reference 3. The survey results also showed that of the forty Canadian academic woman faculty member in their physics faculty members, a very large fraction institutions that responded, 80% of departments. While it is true that the of them have no women faculty them have one or no woman faculty smaller non-PhD granting institutions members at all (60%) and hence member, and almost a half of the tend to have fewer physics faculty responding institutions (45%) have no members, and hence fewer women (continued on page 112)

La Physique au Canada mars à avril 1996 107 WOMEN STUDENTS IN PHYSICS IN CANADA: A DECADE OF PROGRESS

by Ann McMillan, Atmospheric Environment Service, 4905 Dufferin St., Downsview, Ontario, M3H 5T4 Eric Svensson, AECL, Chalk River Laboratories, Chalk River, Ontario, KOJ 1JO

INTRODUCTION faculty reported on elsewhere in this issue of Physics in The CAP collected some data on graduate Canada by Lagowski and TABLE 1 students in university physics as far back Results of CAP surveys McKenna. The survey sheet as 1983/84, from which it is possible to that w as distributed is shown deduce the representation of women. 1 X 3 / 1 4 1W/M 1 « β β / ·7 m i m 1995/96 in Figure 1. It repeats the Then, a decade ago, the CAP carried out a 1988/89 survey and is rather m atai "t ualvw tltY survey of Canadian university physics r e a n o n s e · 24 18 33 37 38 similar to the 1985/86 and departments to estimate the proportion of 1986/87 surveys in content 3r d v a r physics students in Canada who were and layout, except that it now number of women * 60 105 120 103 women. There was little Canadian data * 7 8 8 does not ask for data before number of men 477 661 5 5 7 available at that time on physics, although t o t a l * 537 893 731 660 third year and it does ask for Statistics Canada had data on engineering w om en a s \ o f t o t a l * 11 12 15 16 data at the Post Doctoral level. and physical sciences which could have 4 t h v e a r included a rather different population. The RESULTS results of that 1985/86 survey were number of women * 45 93 107 130 number of men * 4 0 6 654 655 554 presented at the CAP Congress in 1986 The earliest CAP data t o t a l * 4 5 1 747 762 684 concerning the representation and put in context with representation of w om en a s \ o f t o t a l * 10 12 14 19 women in high school physics classes and of women in Canadian physics in the ranks of practicing physicists. Two departm ents is summarized in M Sc other CAP surveys were carried out, one in Table 1 under the column for number of women 23 30 e-9 73 91 number of men 3 5 7 3 1 0 4 7 4 4 7 4 409 1986/87 and one in 1988/89. Now, a 1983/84. These numbers are t o t a l 380 3 4 0 533 5 4 7 500 decade after the 1985/86 survey, a new the result of Mona Jento, who 18 survey has been carried out in order to was the Executive Secretary of w om en a s \ o f t o t a l 6 9 11 13 update the numbers and to get an the CAP for many years, PhD

indication of how the representation of extracting the number of number of women 11 24 2 5 43 102 women in physics has changed over the women from the lists of number of men 233 299 4 11 404 684 t o t a l 244 323 4 3 6 4 4 7 786 past decade. graduate students submitted to the CAP |1|. While 31 w om en a s \ o f t o t a l 5 7 6 10 13 In the fall of 1995, a survey of students universities submitted lists, a P o e t D OC was sent to Canadian physics departments number only showed the initials number of women * * * 9 24 in parallel with the survey of women of the students and some did number of men * * * 114 151 not break out responses t o t a l * * * 123 175

by degree level. The data women as % of total * * a 7 14 shown were assembled * not available from survey from 24 universities.

niIFÜTIOKNAMIR ON WOMEN ϋΉ ΊΠίΤϋ IN PHYSICS P lm e rtmm hi N ov I, 1595 The results of the four CAP surveys TABLE 2 To: F. Ford. Ex-îcuiive Director are also summarized in Table 1. For Results of surveys at 17 universities which Canadian Association of Physicists responded to both 151 Slater Street, *903 these, a request was sent to the Ottawa, Ontario K1P5H3 university physics departments to m i n t L'nivcrjjty: ^ __ complete a form similar to that m i / t t shown in Figure 1. Response rates 1x4 X ttU Contact Person ______nuibar of voian 58 74 increased dramatically after the first number of ian 472 313 t o t a l 530 387 Ait you willing to distribute a survey. There were only 18 questionnaire to your women students? voien aa % of total 11 19 responses to the 1985/86 survey, 4 th f u r while there were 33, 37 and 38 nuibar of uoian 44 95 IJndargradualea Ph.D. Po*t Doc nuibar of Ban 403 362 M S t responses, respectively, to the t o t a l 447 457

1986/87, 1988/89 and 1995/96 ν ο ι ιη aa 1 o f t o t a l 10 21 3rd yr. 4th yr. surveys, out of 63 departments. Bflc Many of the later responses included nuibar of voi«n 30 48 NUkfBER. nuibar of un 310 232 t o t a l 340 280 OF: only the numerical summary, but most university respondents expressed a woian aa t of total 9 17 MALE willingness to circulate a questionnaire PhD FEMALE nuibar of uoian 24 59 to women students. As yet, we have nuibar of ian 299 361 not attempted to do this. t o t a l 323 419 vonn aa t of total Names of female students: 7 14 total nuabar of νοιιη 156 275 total nuabar of ian 1484 1268 grand total 1640 Table 1 includes the total responses 1543 v o ia n aa » o f t o t a l 10 I t received from all the surveys. Unfortunately, a different subset of universities responded to each In order to make more meaningful survey, limiting the comparability of comparisons, different subsets of the data the results. It is nonetheless clear are displayed in Tables 2-4. In Table 2, that the representation of women the results for the 17 universities that students in Canadian university responded to both the first and last survey physics departments has increased are shown. Note that while these 17 over the time period. It is interesting universities represent only 45% of the that in general the number of physics universities that responded in 1995/96, students declines with increasing they represent 59% of the total number of academic level, with the latest survey physics students. While the detailed Fig.l CAP Survey Form being a marked exception. university responses are not shown here.

108 Physics in Canada March/April 1996 it is interesting to note that, except at the last surveys at these universities, although Percent MSc level, the percentages of women are not so substantially at these 25 slightly higher in 1995/96 at these 17 universities as at the 17 covered by Table universities than at the "new responders", 2. The number of women at each level as indicated by the 1995 /9 6 numbers in also increased over the period, although Table 1. the number of men decreased at every level except PhD, and fell 10% overall. While the representation of women has The total number of physics students has markedly improved, the number of male remained relatively constant for these students in physics at these 1 7 universities universities, but their distribution among has decreased over the last decade, except the academic levels has changed markedly, at the PhD level. It is not clear why the with the number of PhD students up 56% third year class in the 1995/96 survey is in this sample of universities. Tables 1,2 so much smaller than the corresponding and 3 all indicate that the number of class in 1985/86. MSc numbers are also women in third year at the present time dow n at these 17 universities, but PhD (1995/96), and their representation, is numbers are up 30%. Is this just the "tail slightly less than in fourth year. This could end" of a larger group that has passed be the beginning of a reversal in the trend through or are students staying at to increased representation. Future university longer to finish their PhDs surveys should help to clarify this point. because of the shortage of jobs and the economic situation generally? Table 4 shows results for the 20 universities submitting data for both TABLE 3 1983/84 and 1995/96. Results of surveys at 25 universities The percentages of women in graduate 'n* "MI J 1 a a / a 1 schools have nearly tripled over this period at Fig. 2 Percent of Bachelors Degrees in number ■ 68 number ■ 474 Selected Fields Earned by Women, tota 1 656 these universities. The 1975 to 1992. I Of ta 1 11 13 15 total number of PhD students has more than ΤΜΓ doubled, while the number o f women 89 52 1 362 number of Masters 598 students has increased women as % o f t o t a l 13 13 2 0 less than 10% . Note KE C that the actual number of 62 women at the PhD level 388 450 as shown in this sample women as % o f t o t a l has gone up a factor of 6 .

number o f women number of men t o t a l DISCUSSION AND women as I o f t o t a l 13 CONCLUSIONS t o t a l number o f women 228 224 322 total number of men 1848 1655 1662 The CAP survey data grand total 2076 1879 1984 indicates several things: women as % o f t o t a l 11 12 16 that the representation of women students in Canadian university TABLE 4 physics departments has Results from 20 universities submitting data for both increased substantially 1983/84 and 1995/98 over the period surveyed, that the number of women (Source: NRC Summery Report, verloue yeere. The data d ie d for prtyalce PhD· earned physics students in •re from (he AIR En r oilmen ta end D e ^ e · · Report· ***) number of men 2 9 7 276 Canada has increased t o t a l 3 1 7 340 substantially and that women as a 1 of total 6 19 Fig. 3 Percent of PhD's Earned by Women in the representation of Selected Fields, 1978 - 1993. PhD women university physics students still number of women 1972-73, 1981-82 and 1992-93. The number of men 2 1 8 458 decreases with numbers given for engineering/applied t o t a l 2 2 9 524 increasing academic sciences in 1981/82 and 1992/93 are women as a % of total 5 level. similar to those shown in our Tables and, in fact, agree with the overall percentages Tables 1, 2, 3 and 4 all shown in the last line of Table 2 for Table 3 shows the results for the indicate that the representation of women 1985/86 (10%) and 1995/96 (18%). universities that responded to the later students has increased. The size of the surveys. There were 1 7 universities which increase varies somewhat with the data Figure 2 131 shows the representation of responded to each of the 1986/87, sets used. It is most striking that, at the women in the U.S.A. obtaining bachelors 1988/89 and 1995/96 surveys and PhD level, representation has essentially degrees in selected fields. In physics, the another 8 that responded to both the doubled over the last decade. percentage of bachelors degrees awarded 1986/87 and 1995/96 surveys. For these in the U.S.A. has risen from about 10% in 8 universities, linear interpolation was These results can be put into context with 1975 to about 16% in 1992. If we arbitrarily used to estim ate numbers for those given by Statistics Canada in compare these figures with those from our 1988/89. Table 3 shows that the "Women in Canada: A Statistical Report" survey for the fourth year and MSc levels, representation of women in physics has [2], Table 5, from this report, gives data we see that the increase in representation definitely increased between the first and for full time enrolment by field of study for

La Physique au Canada mars à avril 1996 109 T able 6 also Tabla ] F ull-lim e university enrolm ent of women by Held ol study, 1972-73. 1981-02 and 1992-93 shows that the representation of 1972-73 1981-82 1992-93 women in all Women Women Women as a % of as a % ol as a % ol fields drops from iota) In total in total in OODs % Held OOQs % Held - 000s % field 53.4% at the bachelors degree Field ol study level to 35.2% at Education 33 4 21.2 56.2 45.0 18.4 67.0 40 4 13 8 66.5 the PhD level. Fme/applied ans 5.9 3.8 59.9 10.8 4 4 63.6 11.2 3 8 61.8 These Statistics Humanities 19.4 12.3 48.1 23.5 9.6 58 8 36.7 12.6 59.8 Canada figures

Social sciences 24 4 15.4 28.9 66 4 27.2 44 8 94.5 32.4 S3 5 indicate that, in

Agncullural/biological 1992/93, women sciences 8.9 5.6 40 4 12.5 5.1 52,2 21.2 7.3 56 8 made up more Engineering/applied than half the sciences 0.7 0.4 2 7 4.7 1 9 10.4 9.8 3.4 18.0 university Heaiih professions 10.3 6.5 51.2 17.0 7.0 63-1 21.2 7.3 65 6 enrolment at the Wathematics/physical undergraduate sciences 4 1 2.6 19 1 8 2 3.3 26.3 9.8 3.3 28 4 level in every Total’ 157.7 100.0 40.4 244.1 100.0 48.6 292.0 100 0 52 2 field except «CM N «οu mm no MKlW iw «W» Of m o tr κ w vuu aM fl m i tttvo Sem· SuMftcj Cmntat ISucmrn C*(•mantf 'on· enginoering/appli ed sciences and mathematics/ph Year ysical sciences. Projected Number of Degrees, 1995-2001 Even at the Soiree: AIP Education and Employment Statistics Division Table 6 Women as a percentage ol lull-time university enrolmenl. by level and Held ol study, 1992-93 PhD level, Fig. 4. ThedarkbarsindicateactualphysicsPhD representation of productionbetweenl 983and1994.The Bachelors and firsi w om en is at least two-tone bars indicate high and low professional estimates for projected PhD production. degree Master's Doctorate Total 33% in every field except these appears more rapid in Canada. Our results Field ol study tw o . Figures 2 from 1985/86 in Table 2 imply that about Education 66 8 65.8 60.0 66.5 and 3 for the 10% of the bachelors degrees in physics Fme/applied arts 62 2 58 8 45.5 61 8 U.S.A. indicate Humanities 61.2 55.8 45.7 59.8 were awarded to women and that, by Social sciences 54 4 46.6 44.7 53.5 that the Agncullure/Diologicai sciences 59 0 49.6 33 2 56 8 1995/96, the number had essentially Engineenng/appliec sciences 185 18.2 10.6 18.0 representation of Health professions 67.7 62.0 43.4 65.6 doubled. Mathematics/pfiysical sciences 29 9 27 1 18.6 28.4 women at the

Total' 534 46.2 35 2 52.2 bachelors degree Figure 3 |3| shows the representation of level overall was women in the U.S.A. obtaining PhD's in about 54 % in selected fields. The representation in 1 992 w h ile at the physics has risen from about 5% in 1978 to Figure 4 |4|, based on American Institute PhD level it was about 37%. Engineering about 1 2% in 1 993. These figures are very of Physics (AIP) data for the U.S.A. offers and physics are the two areas in which consistent with, for example, the 5% in a possible explanation. In the U.S.A., the representation is the lowest. 1 983/84 and the 1 3% in 1995/96 shown in number of physics PhD's is expected to our Tables 1 and 4. Hence, although peak between 1994 and 1998 and then to representationappearstobeincreasingmore decline rather dramatically to levels about rapidly in Canada than in the U.S.A. at the the same as those a decade earlier. If the These results indicate that, in the university bachelors level, the increase in situation in Canada is similar, it would community as a whole, representation of representation at the PhD level seems about explain the large number of physics PhD women at the undergraduate level is no the same in the tw o countries. students reported in our 1995/96 survey. longer a serious concern. However, the This explanation is also reinforced by the science-based professions, particularly Tables 1, 2, 3 and 4 show that not only numbers in third year in our 1995/96 physics and engineering, continue to have the representation, but also the number of survey. For some universities (Tables 1 a problem attracting women students and women university physics students has and 2), the third year class is smaller than the lossof partially trained women students increased in Canada. This increase is most the fourth year class. The number of dramatic at the PhD level. It is still is a problem in the university community for women students is also lower, as is their sobering to reflect on the very small actual all disciplines. representation. Further surveys will be number of women physicists at that level. required to establish whether or not this apparent change in trend is real. It is clear that to change the overall representation in the Canadian Although women are now equitably The data show n in Tables 1, 2, 3 and 4 professional physics community will take represented in university education in indicates that in all years except 1995/96 a very long time. Canada, and their representation in physics the representation of women falls off with has almost doubled over the past decade, increasing academic level, typically by In general, for most of our surveys, the physics still remains one of the areas where about 4-5% (out of 11-19%) from third number of women students drops off with representation of women is poorest. In year to PhD level. Table 6 |2| shows that increasing academic level, as does the addition, women still drop out of physics the representation of women in total number of students. This is not engineering/applied sciences in 1992/93 education relatively more frequently than universally true, however, and the fell from 18.5% (bachelors) to 10.6% men do. Current physics student 1995/96 survey results are different in this (PhD) according to Statistics Canada. demographics leads one to expect that, regard. In the 1995/96 survey, Figures 2 and 3 indicate that the over at least the next several years, the summarized for different groups of representation of women physics representation of women among the new universities in Tables 1, 2, 3 and 4, the graduates in the U.S.A. in 1992 was about hires in Canadian physics positions, and number of women PhD students is greater 16% at the bachelors degree level and hence among the total Canadian than the number of women MSc students. about 11 % at the PhD level. professional physicist population, will Furthermore, the number of male PhD exhibit a slow increase. It will, however, be students and hence the total number of This decrease in the representation of several decades, if ever, before there is an PhD students are also greater than the women with more advanced academic level corresponding numbers at the MSc level. is a phenomenon not limited to physics. (continued on page 11 3)

110 Physics in Canada March/April 1996 WES-WOMEN IN ENGINEERING AND SCIENCE: A CANADIAN SUCCESS STORY AT NRC

by Marie D'lorio, Institute for Microstructural Sciences, National Research Council of Canada, Ottawa, Ontario K1A 0R6

In November 1990, the National Research answering questions and guiding the projet et de directeur de recherche bien Council (NRC) launched a Women in research of four students working with her Those of us who have served as mentors Engineering and Science program in its that summer. Since 1991, preference has hope that the WES Program will continue to laboratories to encourage the participation been extended to candidates in fields in enrich our personal and professional lives for of Canadian women in the science and which women are underrepresented: years to come! Information about this engineering professions. Each year since mathematics, physics, and engineering. program is available through the university 1991, twenty-five outstanding first year awards office and through NRC at the female students enrolled in a Canadian The students who were chosen for this following address: University or in a final year of CEGEP have year’s program were invited to an been selected from across Canada to orientation session at NRC in August. Carole Greffe work for three summers or co-op terms in There, they met prospective mentors, National Research Council of Canada NRC laboratories w hile studying in learned about the research projects in Human Resources Branch scientific or engineering disciplines in various Institutes, and talked to other WES Recruitment Office which women are traditionally under­ students in their first, second and third Ottawa, Ontario K1A OR6 represented. The student is paired with a year in the Program. The WES participants Tel: (613) 993-3543 NRC scientist w ho acts as a m entor to link have established an effective network of FAX: (613) 990 7669 the academic training, work assignments information and activities providing the and career aspirations of the student. In mutual support which often drives first * Sphere, May 1994 particular, the mentor helps identify a class students to surpass excellence. project suited to the student’s interest and provides guidance when needed. The students are encouraged to experience different research environments and supervisors, although some prefer to "grow" within a research group for the three work terms.

The students accepted into the Program are expected to serve as role models for other women contemplating careers in science and engineering and must represent the National Research Council when the opportunity presents itself. Two groups of WES students have now Sheri-Lynn Lewis with Dr. S. Elgazzar, Institute Karla Randell with Dr. J. Balsevich, Plant completed the Program and more than for Information Technology/lnstitut de Biotechnology Institute/lnstitut de technologie technologic de l'information, Ottawa. 85% of these have registered into des plantes. Saskatoon. graduate school or are pursuing careers in science and engineering. Criteria for PIC-PROGRAMME D'INGENIEURES ET CHERCHEUSES: selection of WES participants include: academic interests and performance, UN PROGRAMME CANADIEN COURONNÉ DE SUCCÈS extracurricular pursuits, employment AU CNRC history, initiative, community involvement and communication skills. Each university par Marie D'lorio, Institut des sciences des microstructures, can recommend up to three students. Conseil national de recherches du Canada, Ottawa, Ontario K1A 0R6 Elke Aippersbach from the University of En novembre 1990, le Conseil national de que certaines préfèrent un apprentissage au Alberta spent three summers in Jenny recherches du Canada (CNRC) a mis sur pied sein d’un même groupe de recherche Phipps’ laboratory in the Institute for u nprogrammed'ingénieures et chercheuses pendant trois ans. Les étudiantes admises Biological Sciences (IBS), Tissue (PIC) visant à encourager les Canadiennes à au programme doivent servir de modèles à Regeneration and Transgenics Group. poursuivre des études en sciences et en d'autres femmes qui envisagent de faire During her second work term at NRC, Elke génie. Chaque année depuis 1991, leCNRC carrière en sciences ou en génie et doivent commented: "In a lab like this there’s so a invité vingt-cinq étudiantes très douées, représenter, si nécessaire, le Conseil much to get involved with. This year, I venant des quatre coins du pays, à travailler national de recherches dans le cadre de worked on the effect of a peptide of dans ses laboratoires pendant trois étés ou salons de l'emploi et journées d'orientation hormonal origin on the cellular cycle. Last semestres co-op tout en poursuivant des sur les campus universitaires. Deux groupes year, I was involved in a collaborative études dans des disciplines où les femmes d'étudiantes ont complété leur appren­ SIMS (Steacie Institute for Molecular sont traditionnellement sous-représentées. tissage au sein du programme et plus de Sciences) and IBS project studying a Les étudiantes doivent avoir terminé une 85% de ces diplômées poursuivent des possible treatment of cancer"*. As she première année d'un programme de premier études de deuxième et troisième cycle ou se headed towards pursuing graduate degrees cycle dans une université canadienne ou un sont engagées dans des carrières en in Biochemistry at the University of niveau équivalent au Québec. sciences et en génie. Parmi les critères de Toronto, Elke had a good idea of what a L'apprentissage de ces étudiantes est sélection pour les participantes du PIC, on professional researcher’s career entailed. facilité par le jumelage de chaque compte les intérêts sur le plan académique She added: "In school, you get an idyllic participante à un scientifique du CNRC dont et parascolaire, l'esprit d'initiative, les view of research. If your experiment le rôle de conseiller consiste à aider activités communautaires, la communi­ doesn't work, you still know the results l'étudiante tout au long des trois années du cation orale et les expériences de travail. you were supposed to get. At NRC, you programme, de la guider dans le choix de Chaque université peut poser la candidature don't always get the results you're looking projets de recherche, de la conseiller quant de trois étudiantes. for, but you have to learn to be open to what your failures can teach you." Her à l’orientation de sa carrière et d'être disponible pourdiscuterdecequi a trait aux Elke Aippersbach de l'université de mentor’s perspective on interacting with objectifs du programme de formation et aux l'Alberta a oeuvré pendant trois étés students was: "They ask questions that affectations. Les étudiantes sont dans le laboratoire de Jenny Phipps de we have forgotten to ask somewhere encouragées à diversifier leurs choix de l'Institut des sciences biologiques (ISB), along the way". Jenny Phipps was busy

La Physique au Canada mars à avril 1996 111 groupe de régénération tissulaire et de Women Physics Faculty . . . by recherche transgénique. Au cours de son J. Lagowski and J. McKenna troisième été au CNRC, Elke a parlé de sa (continued from pg. 107) recherche en ces termes*: "Dans un labo comme celui-ci, il y a de nombreux projets have no role models for their auxquels vous avez la chance de participer. undergraduate women students. Cette année, j'ai étudié l'effet d'origine hormonale sur le cycle de la cellule. L'an In Table 4 these Canadian statistics are dernier, j'ai participé à un d'un peptide compared with the analogous statistics projet en collaboration avec l'Institut in the United States of America for Steacie des sciences moléculaires sur un 1994.(3) The situation in Canada is traitement possible du cancer." Alors indeed very similar to that in American qu'elle s'apprêtait à commencer une universities. Maîtrise en biochimie à l’université de Toronto, Elke avait déjà une idée assez CONCLUSIONS précise de ce que serait sa carrière de chercheuse. Elle ajouta: "À l'université, on This article should not be taken as a vous présente une vision idéalisée de la definitive study (see for example recherche. Si votre expérience ne marche footnote 1, also no attempt was made to pas, vous savez au moins quels auraient dû estimate the accuracy of final numbers) être les résultats. Au CNRC, il arrive que on women in physics in Canada. The vous n'obteniez pas les résultats results of this survey suggest that recherchés, mais on s'attend à ce que vous appreniez aussi de vos échecs." further studies could be undertaken in Selon sa conseillère, Jenny Phipps, "le fait order to address questions such as: (1) de travailler avec des étudiants nous force What was the effect of Women's Faculty à être plus vigilants. Ils nous posent des Awards (WFA) (a program sponsored by questions que, parfois, nous avons oublié the Natural Sciences and Engineering de nous poser en cours de route." Jenny Phipps était bien placée pour parler Research Council) on the above puisqu'elle supervisait les travaux de percentages? (2) Do women progress to quatre adjoints d'été dont Elke. Depuis tenure more slowly than men? (3) How 1991, la préférence est accordée aux would the inclusion of institutions that étudiantes inscrites dans des domaines où chose not to reply to the survey affect les femmes sont sous-représentées soit les the above results? and possibly other m athém atiques, la physique et le génie. questions that would indicate ways of Les étudiantes qui ont été choisies pour le assessing and improving the situation for concours de 1995 ont été invitées à une female physicists in the Canadian journée d'orientation au CNRC au mois institutions. We conclude by stating d'août. Elles ont rencontré des conseillers that with 5% representation of women et conseillères, ont eu un bref aperçu des projets de recherche de divers Instituts et in physics departments at the faculty ont pu rencontrer des étudiantes level, the situation for women in physics participant au programme des ingénieures in Canada is comparable to that in the et chercheuses depuis un, deux et trois United States of America, and notably ans. Les participantes du PIC ont mis sur worse than that of many European pied un réseau d'information et organisé des activités qui les épaulent durant leur countries. séjour au CNRC leur permettant d'aller au- delà de l’excellence. REFERENCES ( 1 ) W. J. Megaw, "Gender Distribution in Pour ceux et celles parmi nous qui ont eu le plaisir d'être conseiller et conseillère, il the World's Physics Departments”, ne reste plus qu'à espérer que le paper prepared for the meeting, programme d'ingénieures et chercheuses Gender and Science and Technology continuera d'enrichir notre vie personnelle 6, Melbourne, Australia, July 14-18, et professionnelle pendant les années à 1991. venir! Pour de plus amples informations sur ce programme du CNRC, veuillez (2) Mildred S. Dresselhaus, "Update on communiquer avec le service des bourses the Chilly Climate for Women in de votre université ou avec le CNRC à l'adresse suivante: Physics," Committee on Status of Women in Physics Gazette, Vol. 14, Carole Greffe No. 1, Spring 1 994. Conseil national de recherches du Canada Direction des ressources humaines Mildred S. Dresselhaus, Judy Franz, Groupe de recrutement Bunny C. Clark, "Improving the Ottawa, Ontario K1A 0R6 Climate for Women in Physics Tél: (613) 993-3543 Departments", published by the FAX: (613) 990-7669 American Physical Society and the * Sphère, mai 1 994 American Association of Physics Teachers.

(3) American Institute of Physics; Education, Employment and Statistics Division, data for the year 1994.

112 Physics in Canada March/April 996 THE COMMITTEE ON THE STATUS OF WOMEN IN PHYSICS OF THE AMERICAN PHYSICAL SOCIETY

by Luz Martinez-Miranda

The Committee on the Status of Women in January, 1993, and now has over 600 and the American Association of Physics Physics of the American Physical Society subscribers. Teachers (AAPT). Funded by the National (CSWP) was chartered in 1972. Over the Science Foundation and the APS, this years, the Committee has sponsored Examples of discussions on WIPHYS: program was aimed at determining which activities aimed both at increasing the factors affect the retention and success of participation and representation of women - announcement of government or privately women in Physics Departments at all levels in Physics and related fields. sponsored programs designed to aid in (undergraduate, graduate and faculty) at establishing the careers of women research universities in the U.S.A. The final The CSWP has nine members appointed to scientists; report on this program, written by Profs. three year terms by the APS. Currently, - postings of job listings; Mildred Dresselhaus, (MIT); Judy Franz, th e CSWP is organizing three - news about women in physics; Executive Officer of the APS, University of subcommittees: Education, Industry and - on-line mentorship (issues recently Alabama; and Bunny Clark, Ohio State International, to better enable the discussed include sexual harassment, the University, is available from APS by committee to take advantage of the many impact of changing one’s name on contacting Erika Ridgeway at (301) 209­ eager volunteers who wish to contribute to publications and research, advice on the 3269. This report details specific the committee’s projects. tenure process); recommendations to improve the climate - information on women's events at APS for women in Physics Departments. As For more information on CSWP programs, meetings (postings on informal and the report points out, many of these please contact Tara McLoughlin at APS planned dinners, receptions, sessions, recommendations, including the availability headquarters (301) 209-3231 or e-mail help for those seeking roommates); of safe undergraduate study rooms, [email protected]. - advice on teaching (suggestions for recruitment of women faculty, and textbooks, discussion of different guidance for those combining work studies Some of the activities the CSWP sponsors learning styles). with family responsibilities benefit women are: as well as men, and can lead to a better 1. a Roster of Women in Physics; In order to subscribe to WIPHYS, send an working atmosphere for all department 2. Women in Physics (WIPHYS), a e-mail message to: [email protected] members and students. The program has moderated internet forum; The subject line should be blank, and the received many more requests for visits 3. a colloquim/seminar speaker's list; text of the message should read: than funding or time allows. The CSWP 4. travel grants for women speakers; subscribe wiphys plans to continue this program, visiting 5. Physics Department Site Visit Program. approximately three institutions per COLLOQUIM AND SEMINAR SPEAKER'S academic year. Funding will be provided In addition, CSWP publishes The Gazette, LIST OF WOMEN IN PHYSICS both by the CSWP and the department a quarterly newspaper, and sponsors visited. The Colloquim and Seminar Speaker's list symposia, receptions and presentations at of W omen in Physics is published every the general and divisional meetings of the year and distributed to all Physics American Physical Society. Most recently, Departm ent Heads in the U S.A. and CSWP has sponsored a breakfast meeting Women Students in Physics . . . by others by request. This booklet contains of women in industry, jointly with the Ann McMillan and E. Svensson (continued the names of women speakers and seminar Committee on the Applications of Physics. from pg. 110) titles arranged by field, geographical area These programs are described in the and presentation level (general audiences, follow ing. equality of numbers of women and men in high school audiences, technical seminar). the physics profession in Canada. The list serves as a resource for ROSTER OF WOMEN IN PHYSICS departments interested in inviting women REFERENCES The Roster of Women in Physics is a speakers to their seminar series. database containing the names, addresses 1. Mona Jento: Letter, October, 1984. and fields of expertise of women in TRAVEL GRANTS FOR WOMEN SPEAKERS physics at all levels from student to 2. "Women in Canada: A Statistical The Travel Grants for Women Speakers professional. Academic institutions, Report'. Third Edition, August, 1995, Program is aimed at increasing the visibility government and industrial laboratories ISBN 0-660-15566-4. of women in the field as well as providing interested in reaching a pool of potential students, both female and male, with job applicants in a specific field can 3. Mildred Dresselhaus, Judy Franz and active female role models, especially in contact APS and request a search of the Bunny Clark: "Improving the Climate for those physics departments that do not database. APS will mail jo b Women in Physics Departments", The have any women in their faculty. In the announcements and pertinent information American Physical Society and the U.S.A. more than one third of the research to candidates whose qualifications match American Association of Physics universities have no women faculty. APS the institutions' specified requirements. Teachers, 1995. reimburses institutions up to $500 (US) for The information contained in the Roster is the travel expenses of one or two women 4. Roman Czujko: "Realities of the Physics confidential and therefore the list is not speakers. This program has been very Job Market” in Physics Graduate available for distribution. A Roster Education for DiverseCareer Options, ed. successful since its establishment and in application form appears in every issue of Judy Franz, The American Association of 1993, the APS Council voted to increase The Gazette. Physics Teachers and the American its funding by one third. All Physics and/or Physical Society, 1995. Science Departments in the US are WOMEN IN PHYSICS (WIPHYS) encouraged to apply. Canadian and WIPHYS is a moderated Internet forum for Mexican Institutions are eligible also, the discussion of issues related to women provided that one of the invited speakers is in physics. This electronic forum offers currently employed by a US Institution. unique possibilities to assist in creating an atmosphere of cooperation, mentoring and THE PHYSICS DEPARTMENT SITE VISITS support in a field where women are a PROGRAM minority, and thus often feel isolated. The Physics Department Site Visits WIPHYS was "officially" started in Program is sponsored jointly by the APS

La Physique au Canada mars à avril 1996 113 PHYSICS INDIVIDUAL PROFILE - IRINA CONDREA

After I graduated from the University of was certainly handicapped at the decided that I'd like to continue my studies Iasi in 1989 with a degree in physics, I beginning by my origins, by the fact that I to a PhD degree and my husband agreed. decided to continue my studies at the was Romanian and that I had other ways Tired of the problems we had because of Bucharest University for a Master's degree of looking at things. Adjustment depends our citizenship, we decided to emigrate to in plasma physics. In Romania at that time on the person also, and I can assure you Canada. there was only one Master’s degree that from the moment I understood that program and only 15 were admitted each this was the case, I made a lot of Here we are now, in Montreal, Canada. I year. These 15 people were the best progress. I was speaking Italian am doing my PhD studies in fusion at the students from all the Romanian Faculties comfortably after one year (without taking Centre Canadien de Fusion Magnétique, any lessons) and I was progressing much Varennes. I intend to measure the ion of Physics (there were 5 in the country). more easily in my field after a few months. temperature and the impurity density in the Since I had a Because of this, my director prolonged my central plasma of Tokamak de Varennes by very good fellowship for another 8 months and also injecting a neutral beam in the plasma. It's a'erage for the gave me a lot of responsibilities. an interesting and complex subject. I have .. hole 4 years of already finished all the courses and I have undergraduate I probably forgot a very important aspect started to work on my research subject. studies, I was of my life in those years, my marriage. My husband found a job in a metallurgical accepted into company, where he is production manager. the Master's At that time, my husband had to remain in When we arrived here, we again felt like program. The Romania for bureaucratic reasons. He is we were "nobodies" because we didn't time period for Romanian, too, and you may not know it, speak French (even though we had studied taking the but in Western Europe there are very it in school) and also because this society Master's degree strong laws which impede people from is different from the European one. I think w as one year Eastern Europe from working or staying for that I can say at this point that we have which included extended periods in other countries. I could once again managed to adjust to this 3 obligatory say plenty about the reasons for those society. We now both speak English and courses during the year, and research with laws, but I don't think it would resolve French and we feel well integrated in our a thesis at the end. As I was already anything. The point is that nobody from work groups. We have Romanian and interested in a certain subject which I the Italian authorities wanted to know Canadian friends and we love all the presented in my graduate thesis, I decided about the presence of my husband in my occasions in which we can make new to continue it. I kept in touch with my life. Sometimes I even got the suggestion contacts with people from all around the to "find yourself an Italian and marry him w orld. professor in Iasi who was the head of the and your problems will be resolved”. No plasma physics group at Iasi University, comment. After almost 10 months, I Maybe you'll say that I wrote too much but for the most part I had to deal with my managed to get a work permit and a job about our problems with visas instead of problems alone. It was a very interesting for my husband. He is a metallurgical speaking about physics. Well, in my life, experience - I could play with all kinds of engineer with excellent skills so it wasn't both things were correlated. It is sad to calculations, assumptions and comparisons really very difficult to find an appropriate see how many impediments a Romanian with other fields of physics. Of course, one job for him even if he had to totally change scientist has to face if she/he wants to year is a very short time for a Master’s, fields (to micro-mechanics). We started to continue their chosen career. but in the end I managed to develop an have a happy life, we were 90% adjusted original view on double layers and on the to Italian society and we had a few very Still, I don't regret being a woman in potential relaxation instabilities in a good friends. The problems appeared when physics. My male colleagues continue to confined plasma column. the 8 month fellowship was coming to an tell me that we, the women, have a lot of end and I had no place to go. According to advantages in our work field. I don't think I successfully finished my studies in 1990 their laws I had to leave Italy. My director so. Even if there are laws which are and, after three months, was offered an 8- proposed a 2-year long research contract, supposed to help women, I find it very month post-graduate fellowship at the very well paid and including some difficult to obtain a position. Males Fusion Department of the Energy Research expenses for conferences, work visits etc. continue to say that they want to have Centre in Frascati, Italy. My task was to There was a lot of work but I accepted women in their labs but when they have to make spectroscopic measurements on the immediately because I loved my work and sign for a position they prefer a man. I loved Italy. plasma of a medium- sized tokamak (FTU- There are special cases such as my Frascati Tokamak Upgraded). When I director in Frascati, Dr. R. Bartiromo, who The years in Italy were very happy for me arrived in Italy I had no knowledge of the never made me feel like I was a woman; Italian language. Even though my and my husband. There were still some he considered me first and foremost as a colleagues spoke English, I soon clouds in our sky and once again it was physicist. I am very grateful to him understood that I needed to learn to speak our worst enemy- the authorities. My because he never abused his power and he Italian. Also, upon my arrival I had no husband because of his work permit could knowledge about fusion programs. While I stay in Italy as long as he worked but I had offered me the opportunity to change my had learned something about the principles entered Italy with a student visa and even career and my life. Our male colleagues are of fusion and the use of a tokamak for though I was working, I couldn't get a not used to having women in their labs and nuclear fusion purposes, Romania is too work visa. So, after the 2 year contract I I think that is up to us, the women, to poor to be able to finance such an was supposed to leave Italy. This situation show them that we can speak about important program, so few there know caused us a lot of despair. Only someone physics with them and that we are capable anything about it, with the exception of a who has lived with this situation can know of doing good research. We have to some people at the Atomic Institute in what I mean. cooperate, to give the best of ourselves Bucharest who collaborate with other and also to accept differences in each European Institutions. Fortunately, we are positive thinkers and other. so, 6 months before the end of my This will give you an idea of the feeling I contract we discussed our future plans I don't know if the fact that I'm a married had when I started to work in the Energy very seriously. Should I remain in physics? woman changes anything in my career. Research Centre. In Romania I had been It seemed very difficult for 2 reasons apart Certainly it was not easy for both of us to very appreciated for my work, but here I from my visa: first- only an Italian citizen change countries and jobs, but with a bit felt like a "nobody''. I started to feel can be hired in a research Institute because of reciprocal understanding we have better after a few months as my Italian it is state-run; second - industry is not very managed to have a happy life. Even now improved considerably and I started to interested in hiring physicists and if they that I know how difficult it is to get a job do it is for software development. Should understand the system. Coming from a in physics I would still choose to do this. we stay in Italy? Where would we go? place where you don’t have many I'm sure that all the women physicists can There was no way that we could go back opportunities to one where everything is make important contributions to physics. possible takes a lot of getting used to. I to Romania. After serious thinking, I

114 Physics in Canada March/April I996 PHYSICS INDIVIDUAL PROFILE - NANCY REMAGE EVANS

Where did I start? I went to university with Hill, Ontario, I concentrated on different aspects Space Telescope. In addition, further work an interest in science but not an exclusive of spectroscopy than before. on Cepheid companions using both the IUE interest. It wasn't until second year that and Voyager satellites has given much almost by accident I selected a course in In this case, the masses of Cepheids were clearer information about binary frequency astronomy, and after that I was hooked. I badly needed to confirm our understanding and about the importance of rotation of have thought about whether the fact that I of the physics of the history of the stars, mixing in stellar evolution. So far the 39 was at a women's college (Wellesley) had particularly since they are so important in successful statellite proposals have an effect. As with many areas, there are extragalactic distances. In order to contributed to 45 refereed publications (and probably pros and cons. Certainly the determine masses, pairs of stars in binary numerous conference proceedings). atmosphere in the 1960's (graduated 1966) systems are needed. Although it was which emphasized serious career choices thought at the time that no suitable Cepheid The family situation was more complicated. for women and classes where there was no binaries existed, velocity observations at After 3 years of looking (involving a combination pretending they were really aimed at DDO (and elsewhere) began to turn up of commuting and sabbatical leave), my someone else were highly beneficial. candidates for orbit determinations. This husband was not able to find a position in the same approach also led to information about area. We moved back to Toronto, where I how frequently binary systems occur. This continued research on soft money. When the is important information about star formation Institute for Space and Terrestrial Science (are stars likely to form single or in pairs or (ISTS) was set up as one of the Ontario groups?) which is a very active research Centres of Excellence, I took a scientific position area currently. Ultimately it has bearing on in the Space Astrophysics Laboratory (SAL, how frequently conditions needed to form 1988) and eventually became Associate planetary systems exist. Director of the Laboratory.

In the family/career area during this period In addition to research, we worked on a as I began to search for a permanent job, I number of astronomical statellite projects sometimes wondered whether cover letter sponsored by the Canadian Space Agency. statements that the work had been done The scientific background in SAL allowed us part-time were really taken into consideration to have interaction with small Ontario high when evaluating productivity. Likewise, one tech companies with interests in space can only hope that cover letter statements related technology. During this period, I also about a variety of experience are considered became and Adjunct Profesor at York as strong a proof of broad experience as University, and was pleased to find that my Among things that particularly excited me as physical mobility. applications for operating grants to the an undergraduate were the way in which Natural Science and Engineering Council, clusters of stars provided information about There is a lively debate at the moment in the Canada (NSERC) were well received and the physics of the evplution of stars weekly email newsletter on women's issues my grants continued to increase. This fundamental data such as the masses of from the American Astronomical Society meant that I was able to support several stars. Altough I would not have guessed it at about the best age is to have children during graduate students, as well as undergraduate the time, I have continued to work in some of a scientific career. Perhaps the most summer and work study students. They the same areas, largely because of the healthy aspect of the discussion of a worked mainly on projects usually using exciting new observations which have complex problem is the diversity of opinions satellite data, though this was often become possible both because of technical ranging from early (the energy factor is combined with data obtained at DDO. advances in ground-based observations and important) to waiting until you are also new wavelength regions made available established. I can certainly attest that while Unfortunately in 1994 a decision was taken throughofsatelliteobservations. Encouraged it was not easy to do both graduate work at the Institute to reduce science and by graduation with honours and membership and post-doctoral work on a part time basis, concentrate only on industrial work and the in Sigma Xi, I continued to graduate school, that is option which I found to be workable laboratory was closed. I looked for work supported by a variety of fellowships. as well as very rewarding. extensively in Canada for a year.

For graduate school, I came to the After a year of teaching at Erindale College In 1995, I was offered a position at the Astronomy Department at the University of at the University of Toronto, I took a position Harvard Smithsonian Center for Astrophysics Toronto, where I did a thesis on as Resident Astronomer at the International to work on the Advanced X-Ray observations of variable stars, supervised by Ultraviolet Explorer satellite (IUE) run from Astrophysics Facility (AXAF) and I relocated Dr. J.D. Fernie. It is possible to determine NASA's Goddard Space Flight Center just to Boston. The work on this project which is the radii of pulsating stars by combining outside of Washington, D C., USA. This is NASA's next major satellite project is very measurements their light, color, and velocity a small astronomical statellite for which half exciting, as is readjusting my research to variations. This was my first work on a dozen astronomers supervised all aspects another wavelength region. High energy Cepheid variable stars, which are particularly of the project: taking the data, data studies with this satellite are promising ways important in the determination of distances processing, and assisting with the scientific to provide a better understanding of to galaxies beyond our own Milky Way analysis with visiting astronomers. Working magnetic activity in stars (including galaxy. (As a Flubble Space Telescope key with a small team on such a breadth of Cepheids). Such activity (the sunspot cycle) project, Cepheids were featured in a TIME projects was an exciting and demanding has important effects on many phenomona magazine cover story last year). experience, and left me at times busier than on earth, such as communications and I have ever been. growth cycles. I also hope some work on This period was the beginning of the juggling of star clusters will lead to a better career demands with family demands, In my own research, adding the ultraviolet understanding of processes producing X- culminating with the arrival of a second child observations to the long-term velocity rays in hot stars. and a thesis at nearly the same time. This observations I had been making in Ontario combined with a husband with tenure (Marting provided the ability to attack many scientific Commuting between Boston and Toronton G. Evans, Professorof Organization Behavior questions. A mass determination of the (where my husband is) is also requiring some in the Faculty of Management Studies at the Cepheid SU Cyg became possible by readjustment, although it is possible now that University of Toronto) limited possibilities to measuring the velocity of its hot companion the children are in university and graduate travel for a post-doc. It was quite using the IUE satellite (with Dr. C.T. Bolton, school. I can only thank my husband for his fortunate that Dr. J.R. Percy offered me a part­ University of Toronto). This has lead directly support in this crazy existence! time post-doctoral fellowship at the University of into a more extended program of additional Toronto. Though I continued to observe at stars (Bohm-Vitense, Evans, Carpenter, and Can I predict what is next? I wouldn't dare - David Dunlap Observatory (DDO) in Richmond Robinson) using the more powerful Hubble either in science or in job title.

La Physique au Canada mars à avril 1996 115 PHYSICS INDIVIDUAL PROFILE - DIANE PINSONNEAULT

A 31 ans, physicienne, je travaille depuis 4 matière sont peu familiers sur terre mais réaliser des appareils pour mesurer des ans pour l'Institut National de la Recherche très répandus dans l'univers. Une matière paramètres du plasma et de les rendre Scientifique INRS-Énergie, un centre de mystérieuse pour laquelle j'ai développée disponibles. Dans le but de favoriser les recherche universitaire dans le groupe de un grand intérêt. collaborations internationales et l'échange physique des plasmas. Nous sommes une de connaissances, on est appelé à rédiger vingtaine affectés au laboratoire du Centre Partagée entre le désir d'être confrontée à des articles scientifiques et assister à des Canadien de Fusion Magnétique CCFM un milieu industriel et celui d'acquérir une congrès, ce qui m'amène à voyager pour étudier la fusion dans le but de bonne connaissance théorique des plasmas souvent. Ceci me permet de diversifier transformer la matière en énergie. ainsi que de découvrir leurs applications, je mon expérience et d'étendre davantage Pourtant, bien que comme pour la plupart me trouvais très heureuse quand j'ai eu mes connaissances. de mes collègues, la carrière dans laquelle l'occasion de combiner études et je me trouve n'était pas mon premier recherches au CCFM. J'ai entrepris une Une carrière en science est exigeante, je choix. maîtrise en physique des plasmas à suis souvent amenée à faire un choix entre l'Université de Montréal sous la direction ma carrière et ma vie personnelle. Dès le Du plus loin de d'un professeur qui était membre du début, j'ai du m'engager à fond afin mes souvenirs, CCFM. Ce centre participe à un programme d'acquérir les compétences requises et je m’émerveillais mondial pour le développement d’une faire mes preuves. Il faut s'intégrer à son devant les source d'énergie viable à long terme à milieu de travail. Au CCFM, le milieu est ressourcesde la partir de la fusion, un aspect fort moins compétitif que dans d'autre nature et intéressant qui me plaisait. À Varennes, institutions. En sciences, où les hommes comment elles près de Montréal, le centre exploite une sont majoritaires, j'étais intimidée par la pouvaient être machine de type tokárnak, làeVfTokamak complicité dont ils font preuve entre eux. transformées en de Varennes), qui permet de confiner Cependant, j'ai su développer des affinités nouvelles efficacement le plasma afin d'étudier la avec certains confrères créant une applications. Je fusion. La complexité d'un projet de cet atmosphère de travail agréable. J'avoue m'intéressais à ampleur exige un travail d'équipe que j'ai toujours soigné mes relations. Bien la mécanique et composée de chercheurs, d'ingénieurs, de encadré, je suis encouragée et souvent à l'outillage de techniciens et d'informaticiens. Ce milieu épaulée par mes camarades de travail. l'atelier de mon père. Le soutien de ma multidisciplinaire qui fait appel à la famille a joué un rôle déterminant dans technologie de pointe et à l'expertise des Au CCFM, c'est l'état qui subventionne la mon cheminement. Mes parents ont entreprises industrielles m'a permis de recherche à long terme. Compte tenu du suscité chez moi le désir d'indépendance et développer des connaissances et une contexte économique actuel, l'avenir du de réussite. Pour ma mère, l'éducation expérience en recherche scientifique. J'ai centre est incertain et les perspectives de 'était prioritaire. Fascinée par la dû acquérir la formation voulue pour carrière en physique sont peu nombreuses. transformation de la matière et curieuse de travailler au sein de cette équipe dont la D'après une convention, une carrière de nature, le génie chimique répondait à mes qualité des travaux est reconnue. Ce fut scientifique requiert un diplôme PH.D et de aspirations. Au moment du choix, les une expérience parfois difficile mais qui plus en plus un post doctorat afin de sciences se sont imposées d'elles meme. s'est révélée très enrichissante. Comme de mener leurs propres expériences. Par Je n'ai donc pas hésité à m'engager dans fait, avant la fin de ma maîtrise, le CCFM contre, je ne regrette pas mon choix. Avec une carrière en sciences appliquées. m'a proposé un poste, alors que les qu’un diplôme de maîtrise, je suis très Cependant, durant mes études au cégep, emplois en science se faisaient rares. Mon heureuse d'avoir un emploi qui me permet un excellent professeur de physique, un cheminement académique a pris fin et je de faire de la recherche et de me mettre en bon vulgarisateur scientifique a su me me suis jointe à l'équipe du centre. Ma valeur. Pour le moment, mes récompenses captiver et susciter mon intérêt pour la motivation à devenir professionnelle m'a résident plus dans la satisfaction du travail physique. Il m'a fait découvrir la permis de rédiger mon mémoire de maîtrise bien fait que dans le salaire ou la stabilité satisfaction de comprendre le fond des tout en occupant un poste de chercheur. d'em ploi. choses et le défi que ça représente. Dès lors, c'était décidé, j'allais poursuivre des Je suis très satisfaite de mon emploi qui Jusqu'ici, avec une carrière aussi bien études en physique. Après l'obtention de est aussi enrichissant qu'exigeant. remplie, je vois évoluer mes intérêts et mon diplôme B.Sc. de l'Université de Responsable d'un projet d'équipe, je dois multiplier mes activités qui s'étendent de la Montréal, j'ai décidé de continuer ma entre autre, gérer un budget, faire des musique à la plongée sous-marine. La formation en physique des plasmas aux études scientifiques, faire de la discipline, l'organisation et la persévérance études supérieurs. Les plasmas qui programmation, mettre en application mes me permettent de concilier ma carrière et représentent le quatrième état de la connaissances acquises pour concevoir et mes multiples intérêts.

116 Physics in Canada March/April 1996 PHYSICS INDIVIDUAL PROFILE - DEBORAH POIRIER

I have loved science since I was a little was the type of teacher whose enthusiasm One single woman did however lament girl, drawing mould spores in grade two for understanding physical systems was that her chosen field was hardly an and sitting on the balcony in a infectious. He turned exploring physics aphrodisiac to suitors. We found that thunderstorm with my father to watch the into an exciting journey with lots of hands- m ost young men's reactions to our being lightning. Neither of my parents is a on laboratory work and problem­ in physics fell into two categories: the scientist, but both have always shown a solving. Mr. Fahmi only gave oral exams, "You must be smart", and the "Hah! I great deal of respect for the sciences and because he was most interested in seeing failed that in high school”. My single both gave me a strong sense that it was a us think a problem through, rather than friend was very pleased when one fellow very honourable career to pursue. In high memorize a proof and dutifully scribble it said, "Oh, e = meI 2!". I think that we all school, I took extra physics and biology dow n. felt comfortable and accepted in the classes and decided that I wanted to department and didn't necessarily feel an become a doctor, since I expected that it I have since read that some girls learn imbalance. The only problem that came up involved diagnosing and puzzle-solving. I science better when it is taught was a visiting lecturer showing slides of began CEGEP in a health sciences program interactively and they are given solid, scantily clad women during the course of which included mandatory humanities and hands-on examples of the concepts that a serious talk. literature courses, which I viewed as a they’re trying to grasp. That certainly dilution of my studies. However, my mind holds for me, so it was a natural choice for From Concordia I went on to INRS-Energie, quickly changed on that point - within one me to turn to experimental physics as an a graduate arm of Université du Québec, to semester I had changed into a social undergraduate at Concordia University. Up do a Master's degree in plasma physics. I sciences program and declared confidently until my arrival there, it hadn't really carried out my experimental work on to my shocked mother that I would NEVER occurred to me that physics was an Tokamak de Varennes, Canada's largest take calculus again. unusual choice for a girl. My family had fusion facility. I am now nearing the end of always supported my scientific leanings, my doctorate, and actually have the During my two years taking me to the library every weekend pleasure of sharing a lab setup with in CEGEP I became when I was a girl, and telling me that another woman. What happens after I involved in the absolutely anything was possible. Being finish is anyone's guess! school newspaper, the only child of a father who was (and is) T h e Champlain a born tinkerer ended up being excellent At an American Physical Society meeting Bugle, working as preparation for experimental work. We of the Division of Plasma Physics a few copy editor and later would build things together and frequently years ago, I attended a wine and cheese as news editor. go to the lumber yard or the hardware for women in physics, along with the 20 or When one of my store for provisions. I expect that had I so other women delegates (and at least as stories was picked had a brother these "unfeminine" pursuits many hungry men). Until then I don't think up by the Canadian may have fallen to him, but I guess I just I ever really felt the impact of the lack of University Press I got lucky! By the time I moved into my women in physics. It was a real pleasure seriously entertained first apartment, I could tune a car, and to meet these women, especially the more th e idea of change my brakes. established physicists, as until then I had becoming a yet to meet a senior experimentalist who journalist, and even Despite my Mr. fix-it upbringing, I still had was a woman. One even came along with worked a few evenings at the McGill Daily. the feeling that men just magically knew her physicist husband and their baby. I began dating the entertainments editor, a about all things mechanical, and cars in Since then I have come to the strong belief young blues musician, who introduced me particular. That notion was finally that role models are essential for young to jazz. (That was 14 years ago. Now dispelled one day when I was working on women considering science as a career. It HE's a doctor and we’re still together...) I my car in my parents' driveway. I had helps enormously to see someone like you took courses in Middle East politics, moved out a year earlier, but still returned successfully doing the thing for which you philosophy, and TV production, and made to the house to do car maintenance in case are training. Gymnasts and divers have to friends who spent their afternoons painting I should get myself into a jam. My father visualize difficult moves before they can be and sculpting. But slowly I began to long came out to look at what I was doing and attempted. Perhaps the same is true for once again for the structure and discipline after a while I realized that I knew more young women in physics. of science, and added a biology class as an about my old car than he did, mainly elective. I decided then and there that I because I had spent so many hours It was after that APS meeting that I was far more comfortable and happy when banging away at it with the shop manual in met Ann McMillan and Eric Svenssen, two thinking about science, and began applying my hand. I learned that he didn't tireless members of the Committee to to university science programs. I suppose necessarily know every detail about fixing Encourage Women in Physics of the CAP. we don't ever really know what's good for cars, but he had the confidence to tackle We and several others have worked us, but in retrospect, I am grateful that I any problem that came up. I did my next together over the past several years to had the opportunity for my brief foray into big car job in my own driveway. constructively change the face of physics, the arts, which opened before me a whole and this special issue on women is just one new w orld. My graduating class at Concordia had all of of the ways. We hope you like it. six students, with two women. The I then had to pick a major to write on my previous year had one, so I always had application forms. I can credit (or women in my study groups, and together blame) Mr Fahmi, my high school physics we were very involved in the society of teacher, for making my decision for me, physics students. We also all w orked as although he probably doesn't know it. He lab demonstrators and course markers.

La Physique au Canada mars à avril 1996 117 PHYSICS INDIVIDUAL PROFILES - RENAISSANCE WOMEN

It has long been a mystery to sociologists Catherine Lucas Carrie Klatt and educators why more women tend to As long as she can remember, Catherine As for me, I am finishing off my study the liberal arts than the mathematical Lucas has always been interested in undergraduate studies in theoretical sciences. This could be caused by many science. She enjoys the theoretical aspect Physics and Philosophy. After my first reasons, including the influence of society of Physics and, like Michelle, what started few years of Physics I was disillusioned by or biological differences between the sexes. as an elective blossomed into a major the fact that I could now solve many My purpose here is not to examine these interest. Catherine was interested in a mathematical and artificial Physics reasons, but rather, to present the story of wide variety of areas and wanted to problems but, I had not yet had an four young Canadian women who are cultivate new ideas and develop necessary opportunity to question the foundations of presently finishing their fifth and final years skills. Catherine is firmly opposed to the what I was being taught. I have found at McMaster University having completed segregation of the arts and sciences, and that the two subject areas have a great the requirements for both honoursPhysics is encouraged by the recent trend in deal to offer one another. Physics offers and Arts degrees. During their universities to promote interdisciplinary Philosophy more problems to work on and undergraduate education they have fields. provides an alternative understanding of explored both sides of campus and have the universe. For me, it was Philosophy found that perspectives from the arts and Catherine found that Physics enabled her that gave Physics back its beauty. Its sciences are often complementary. to bring a logical and systematic viewpoint critical style opened new arenas to to Comparative Literature. Apart from the consider and various interpretations to try. obvious enhnacement of writing skills, she I found that it was only through a believes that Comparative Literature has combination of the two that I was able to other contributions to make to Physics. make sense of either. She says: "Comparative Literature is the study of literature in different languages. After asking my three classmates about The central problem of Comparative their interests and opinions, two points Literature is: how much of the meaning is became overwhelmingly obvious. First, we lost in translation? An interesting problem all agreed that today, especially in for the physicist to think about is, with academia, we are confronted with the Mathematics being the language of problem of specialization. To know Physics, do we lose meaning in the something so deeply at the expense of translation to verbal language?" Since it is how it relates to other areas is to not with language that we teach and know it completely. As a result, communicate physics to other people, how specialization, especially at an early point can we be sure that the presented picture in one's education, proves limiting. As Michelle Hilts is complete? students and scientists it is important to Michelle Hilts was born and raised in Deep appreciate the position of others and how River, Ontario, but jokes that her parents Soumi Ghosh their interests relate to our own. are the only two non-physicists in town. Soumi Ghosh is the kind of student who Her father teaches physical education and just wants to know everything. She Second, as expressed most clearly by history and her mother art and english at thought Physics would be a good place to Michelle, "women aren’t men and the the local high school. With an arts and start. Her interest in Psychology began her shouldn't try to be". Even though women science background, Michelle had always second year of university and she has have the same potential and interest in planned to study both areas at university. sampled a variety of courses covering Physics as do men, they often bring a She was enticed into Physics in first year everything from abnormal Psychology to different viewpoint to the study. Soumi when her professor urged her to apply for Neuroscience. She views the psyche as a commented that I could have done this the Targeted NSERC Summer Award. 'black box' and now seeks to know what article on men and women who are it is that makes us think and act in the studying Arts and Physics but most of my After two years of intense Physics training, way that we do. For Soumi, it is through examples would still have been women. It Michelle longed for some variety in her Physics that one tries to find truth in the would seem, at least for this group of studies. She decided to include a few more universe and it is through Psychology that students, that there is something in the Anthropology courses in her program and one tries to find truth in humans. She liberal Arts that is not in Physics that we was later surprised to learn that the two plans to bring these ideas together through just cannot, and perhaps, should not, do fields were connected. Last summer graduate studies in the Philosophy of without. If women have a natural interest M ichelle had the opportunity to use Physics Science. in more Artsy endeavours then this will w ith Archaeology in a summer NSERC add to the diversity in Physics. Women award held at Simon Fraser University. She Soumi contends that studying Physics has also develop different approaches to worked with Dr. Erie Nelson using helped her appreciate the material side of problems and introduce a warmer and Magnetometery to search for buried earth human behaviour. And how does she see more cooperative environment. Basically, ovens. Psychology influencing Physics? "Theories we bring those things to the Physics in Physics are very much motivated by the community that are part of women and not Michelle believes that Physics has helped personality type of the kind of person that of men. her studies in Anthropology by giving her studies Physics. Think of how Mozart or the ability to approach problems Monet or even Karl Marx would have The moral of the story is that as women in analytically. She finds that she has profited described Physics and how their theories physics, we do not need to enter the from a study of Anthropolgy by becoming might have given Physics new insights." profession as sheep in wolves’ clothing in a more complete person and by gaining a Soumi believes that by studying order to be successful and productive. greater understanding of humanity. Psychology we can eliminate the human There are special attributes that a female Michelle is planning to explore the bias in science and come to an presence brings to the contemplation of connections between the two fields in understanding of the fundamentals of the the universe. Their specific interests can more depth during graduate studies in the universe. only add a new dimension to the study of application of Physics to Archaeology. Physics.

118 Physics in Canada March/April 1996 PHYSICS INDIVIDUAL PROFILE - MARY ANNE WHITE

Dr. Mary Anne White has been a member with John White (who was then Director if you adhere to the old adage that vacuum of the CAP since shortly after receiving her of l'Institut Laue-Langevin, Grenoble). In lines distinguish the fields (metal for PhD, although all her degrees are in addition, Mary Anne held a Junior physicists, glass for chemists). chemistry. However, she has long been of Research Fellowship at St. Hilda's College, the opinion that physics and chemistry are providing her first (and very interesting) At present Mary Anne has five students in very, closely related subjects. Indeed, experience with a women-only educational her research group - two PhD students, some of the most interesting science institution. two MSc students and one honours project occurs at the interface between physics student. Four students have complete and chemistry. In 1981, NSERC smiled on Mary Anne PhD's in her group, and one student has again, and she was awarded an NSERC completed an MSc. Of those completed, University Research Fellowship, which she all are employed in the USA. Of the initially took up as an Assistant Professor chemists, two hold positions at universities (Research) at University of Waterloo. In and two are in the pharmaceutical 1983, with the offer of a tenure-track industry. The physics PhD has chosen to position, Mary Anne moved the NSERC apply his excellent experimental and URF to Dalhousie U niversity in Halifax, theoretical skills in the field of medical where she has risen through the ranks to physics. the present position of Professor of Chemistry and Professor of Physics. Most of the work in Mary Anne's lab is Although Mary Anne teaches only in supported by NSERC through research Chemistry, she has had research students grants. She has also held contracts or g rants from both Chemistry and Physics. from NATO; Stelco; E.l. DuPont; Energy, Mines and Resources; S.C. Johnson; Like most professors, Mary Anne's work Canadian Indust rial In novation Cent re. Mary involves a balance of teaching, research Anne has been author or co-author of more and administration. Not only does Mary than 70 research papers and one book A native of London, Ontario, Mary Anne Anne enjoy teaching and research, but she chapter. In addition, she is just com pleting a graduated from the University of Western has received several recent recognitions textbook (working title: "Properties of Ontario in 1975 with the Alumni Gold for these aspects for her work, notably the Materials") for a materials science class Medal in Chemistry. Her first research Faculty of Science Award for Excellence in w hich she has developed. experience was in the Physics Department Teaching (1993), the Alumni Association at UWO in 1972, when the first-year Award for Teaching Excellence ( 1 993), the On the personal side, Mary Anne is married physics lab instructor, Pat Chefurka, hired Stig Sunner Memorial Award of the to Robert White. Although they met when Mary Anne as a summer research assistant Calorimetry Conference (1994) and the they were both graduate students in to work on Langmuir-Blodgett films. It was Noranda Award of the Canadian Society chemistry at McMaster, they really got to this taste of research, along with a love for for chemistry (1996). In 1991, Mary know each other on the baseball field (Rob teaching, that determined Mary Anne's Anne visited 1 1 Canadian Physics was the captain of the organic chemistry career path. Departments as a CAP lecturer, presenting team, and Mary Anne - being a physical a lecture "Properties of Matter: From chemist - was the team statistician). Rob Supported by an NSERC 1 967 Science and Fudge to Photocopying". is also a faculty member at Dalhousie Engineering Scholarship, Mary Anne University. Their research areas are quite studied for her PhD with the late Jim Mary Anne's area of research is thermal far apart (Rob is a biological chemist) and Morrison, who was then Director of the properties of materials, especially solids they have never yet managed a laboratory Institute for Materials Research at with weak orientational forces where collaboration (those biological systems McMaster University. Although Jim taught dynamical disorder is possible. She leads require too high temperatures for Mary chemistry at McMaster, he supervised both an experimental effort in which the Anne's cryogenic interests!), but they have chemistry and physics students, and his approach is measurement of thermal (and collaborated on two children - David (b. lab was located in the physics wing. In related) properties of solids, usually with 1982) and Alice (b. 1985). addition, without knowing their addresses, custom-designed apparatus, in order to it was difficult to guess whether the understand fundamental processes Outside of teaching, research and family, (many) visitors to the lab were physicists governing such matters as heat Mary Anne is interested in music and also or chemists. This atmosphere provided an conduction, polymorphism, and in bringing science to the general public. excellent introduction to first-class thermodynamic stability. The systems With several others she helped open research without labelling it "physics" or studied have been chosen to probe Discovery Centre, an interactive science "chemistry". Mary Anne’s PhD thesis title particular intermolecular interactions: centre in Halifax. She also has been was "Orientational Ordering in Solid inclusion compounds have been very involved with Discovery Channel (she had Methane at Low Temperatures”. useful in this regard, leading to a general a spot called "How Things Work" in their understanding of heat conduction in inaugural season), classroom visits and In 1979, M ary Anne was awarded an molecular systems which is quite different radio (e.g. Quirks & Quarks). Altogether, NSERC Postdoctoral Fellowship, and she from the "textbook" cases of simple solids. she has a very full and fun life! used the opportunity to spend two years at (Optic modes play important roles in Oxford University, splitting her time molecular materials). The work is between calorimetric studies with Lionel "chemistry" in the sense that the systems Staveley in the Inorganic Chemistry studied are mostly molecular, but most of Laboratory, and neutron scattering studies the measurements can be called "physics"

La Physique au Canada mars à avril 1996 1 19 MARRIED TO A FELLOW PHYSICIST, 2000 MILES AWAY

by Anna Hayes and Stephen Sterbenz

The family profile of a physics couple opposite ends of the continent. We were physics 2000 miles away. Of course, we might seem a mundane subject to feature graduate students together at Yale at the talk on the phone as a family several times in a journal. As one friend put it, "you nuclearphysicsIabunderD. Allan Bromley, a week (the phone company loves us), but don't really want to tell about any of the and we got married while at Yale. Steve is when it comes to two-year-old children, interesting stuff and the rest nobody cares an experimentalist in nuclear physics and I the phone is not a particularly good form about". Nonetheless, we decided to am a theorist. After graduate school we of communication. In fact, half the time accept the invitation to produce a profile, maintained situation (3) for a while, we're not quite sure if Ciara is even encouraged partially by the hope that it obtaining postdoctoral positions together listening, and the rest of the time we're might help raise awareness of some of the at the University of Minnesota. From not sure she knows she's talking with a issues facing physics couples. Minnesota we moved to Los Alamos to person. take up our second postdoc positions. That we have not chosen to switch to the Toward the end of our postdocs at Los first of the three options I presented above Alamos (1991) I was offered a permanent for dual career couples reflects the reward position at Chalk River. Everyone in we get from physics. The greatest reward nuclear theory was (and still is) finding it is probably just that which every physicist very difficult to get a permanent position, feels who has the luxury of being paid to and so this seemed quite a stroke of good do what he/she loves to do. We both fortune. However, there simply wasn't a agree that physics has been a good career position at Chalk River for Steve at the choice in terms of on-the-job satisfaction. time. Nonetheless, Chalk River being a Furthermore, being married to a fellow large institution, we had some hope that physicist has had some advantages. One things might open up in a year or two. of these is having someone to whom you Just after I took up my position at Chalk can ask that dumb question that River, Steve was offered a permanent you're too embarrassed to admit your position at Los Alamos. There was no confusion on to anyone else. We probably position for me there, but again there engage in more shop-talk than even the The major difference between our family might be possibilities in a year or two! We average physics couple, since we share the and "normal" families is that Steve is a did not foresee what the job climate and same subfield. The experimental vs. staff member at Los Alamos National research budgets were to become. theoretical split in the family helps to keep Laboratory in New Mexico and I am a staff egos under control. In fact, we published member at the Chalk River Laboratories of We would define ourselves as a very '90s a comment in Phys. Rev. together recently. AECL in Ontario. These two labs are family' - which means complicated. Ciara, Another advantage is that we tend to about 2000 miles apart. Thus, we find our younger daughter, lives with me in know about twice as many people in ourselves running two households and Canada most of the year, and Maeve has physics as we otherwise might, and some living apart most of the year. We have just begun to do extended stays with Dad of these connections have lead to fertile two children, Maeve (7 years old) and in Los Alamos. Changing schools halfway collaborations. Ciara (2 years old), who talk about 'our through the year seems to be something house in Candada' and 'our house in you can get away with when you're seven A large fraction of our conversations Mos-ahmos'. years old, and Maeve actually doesn't concern physics. The fraction probably seem to be uncomfortable with that. For crosses the 50% margin if you include Living this odd life style has been difficult, me, though, trying to raise two children physics gossip! Daughter Maeve recently but we feel that in some sense it was alone while doing physics is no easy task. provided an interesting comment about almost inevitable. Dual physics couples I learned quickly to change some of my this. Steve found himself lacking a are confronted with three possibilities: ( 1 ) parental standards. For example, being babysitter one Saturday and ended up one of the two quits physics, (2) both stay late for school and eating frozen dinners in taking Maeve to sit at the back of the in physics but live apart, or (3) they obtain the evening has become part of daily life. meeting room at a physics conference. positions together (or at least in the same Dressing the children in matching socks is When I asked her later what she thought, geographic region!). Situation (3) is a thing of the past, but so far we have no she said that it was no different than the obviously the ideal one. However, it is evidence that our situation has been usual conversations Mom and Dad get also the most difficult to achieve. harmful to them. into, especially when we have our friends Situation (2) is easier to arrange than (3), over. but of course much harder to arrange than However difficult the logistics of single (1), since one of the two can always quit. parenting, I see that the one living away I think it's fair to say that the details of our Unable so far to achieve (3), we have for from the children has the harder role by careers are not particularly significant now made the agonizing choice between far. Like all parents, witnessing and when it comes to explaining how it is that (1) and (2) in favour of (2). We have sharing the various milestones our children we find ourselves working at different encountered a wide range of opinions on pass brings us great joy. Hearing by institutions. This is because in the present the wisdom of this choice. phone, or even worse, by e-mail or job climate it is unrealistic for most couples voice-mail, that your toddler has learned to to expect to find positions together. At A brief history of our careers may help walk or to talk, or that your second grader the same time, the 1990 AIP survey of clarify how we got ourselves into the can read or is in the school play can really members of the American Physical Society second of these classes, working now at make you question why you're doing shows that about 70% of women

120 Physics in Canada March/April 1996 members are married to another scientist. implications for people like us. Making an expenses. The luxury of living together as It's worth noting, however, that the same offer on merit alone makes the selection a family and working full-time in physics survey found that "women do not appear clearer and easier, and little real harm is seemed worth the cost. to be in favour of special consideration; done. If the candidate does chose to most of them simply want the barriers to decline the offer because of the spouse's Our careers have been very rewarding and their success removed". I subscribe to this lack of an offer, then the institution can successful for us as individuals. Steve is point of view myself. still make an offer to the runner-up if the now managing a very large program at Los decision is demanded in a timely fashion. Alamos, and I feel I have achieved A barrier that some women have faced reasonable recognition in my field, but involves opinions held by some other Since setting up our two separate homes these successes have come only with physicists on the issue of possible in 1991, we have managed to live together great sacrifice. The overall situation, pregnancy or maternity leave and its as a family for an extended period only involving family trips as frequently as can bearing on a woman's application for a job when Ciara was born. About a month be arranged (about every six weeks to two or a fellowship. The question of how before the birth, Steve took family leave months), has been bearable, but only by a pregnancy might affect our jo b from Los Alamos. During this month we small margin. Maeve enjoys a very good performance has never been raised both worked at Chalk River, Steve keeping relationship with Dad which may have explicitly with us by any employer. up with things back in Los Alamos but also been developed in part as a result of our However, both of our daughters were born helping on a volunteer basis in an unusual lifestyle. She appears to accept during frantic and critical times in our experiment here. After Ciara was born I our situation with only minor complaint careers and we were very concerned about took maternity leave from Chalk River and and is pretty much a happy kid. Ciara is this issue. In fact, in connection with moved to Los Alamos. Being a physics too young to express her feelings in the Maeve's birth (while we were at U. fanatic, I used my leave as a "sabbatical" form of a complaint. She talks about Dad Minnesota), I spent not more than about at Los Alamos, and so we lived as a a lot, but between visits she sometimes three weeks away from work, thanks 'normal' family in situation (3). I worked seems even to forget what he looks like. largely to my sister's being able to come essentially full-time in the theoretical We haven't found the ultimate solution to over from Ireland and act as nanny for a division at Los Alamos, who kindly our problematic situation. In fact, I do not w hile. provided me an office and computational know whether there is a perfect solution to facilities but no salary or expenses. From the obvious problem that we and most Perhaps the trickiest obstacle we have met a physics point of view this was a good other physics couples face. But we still at job interviews is the grilling to which we year, and I was able to use the opportunity remain hopeful that, in our case, it is are generally subjected on the issue of the to get involved in new collaborations. somehow just around the corner. 'trailing spouse'. This arises because most However, my drive to do physics did cost potential employers do not want to make us many thousands of dollars in daycare a job offer to someone who may turn the offer down because his or her spouse can't find a job at the same institution. In all job interviews, we tried to make it clear that we were not asking for two jobs, because we felt that our probability of success in a DIRECTORY OF WOMEN close-coupling arrangement was dramatically diminished. Nonetheless, at one university, we discovered indirectly PHYSICISTS and long after my interview that although I was the top candidate, I was not offered The CAP is currently updating its Directory of the job because I was married to a physicist. Eventually, the problems that Women Physicists and invites all women physicists this issue raised at job interviews became so serious and frustrating that we thought to register in this Directory. of circulating a rumour that we were about tq get a divorce! For information/registration form please contact

In surveying some male physicists whose the CAP office at spouses are not physicists, we found that in general they were not asked to spend Suite 1 12, McDonald Building, significant time discussing their spouses during job interviews. In our opinion, this 1 50 Louis Pasteur, male/female asymmetry is unfair. We feel that the best candidate should be offered Ottawa, Ontario K1N 6N5 the job and that couples should be given the opportunity to decide for themselves Tel.: 613 562-5614; Fax: 613 562-5615; whether or not they want to chose the second of the three options. We recognize Email CAP@ Physics.uottawa.ca. that this policy may have difficult practical implications for university departments and laboratory administrators, but would ask them to consider the far more profound

La Physique au Canada mars à avril 1996 121 PHYSICS FAMILY PROFILE: JOHN BERLINSKY AND CATHERINE KALLIN

We are delighted to have the opportunity excitations from the FQHE state. In the important of all, however, was the to write for Physics in Canada about our Fall before graduation, like any other unexpected but welcome realization that experiences as a "physics couple." This finishing graduate student, she sent out a we were fated to become parents. type of article is useful for a number of number of letters applying for post­ reasons. On the one hand, it documents doctoral positions and then waited. Being This was where the flexible arrangement some of the internal barriers which are Canadian she also applied to NSERC which with ITP and UBC paid off. I rented a built into the academic/research system had generously supported her graduate small house on a large lot in the Dunbar and which are more or less invisible to work. As frequently happens, she then area of Vancouver, and Catherine moved everyone except those who are directly spent months biting her nails, waiting for up at the beginning of August 1985, with affected. At the same time, it allows replies, then had one day of pure ecstasy the understanding that she would be back those of us who are in this situation to when the first offer letter arrived, and next by late December for the last six months "compare notes". In our experience, this was plunged into confusion with the arrival of her post-doc at ITP. I had an agreement type of comparison frequently reveals a of the second offer. The two key offers with my department that I would do all of surprising consistency and recurrence of happened to come from two Nobel prize my teaching in the Fall and then spend the similar experiences. For these reasons we winners who were known to be somewhat following semester at ITP, and Catherine hope that our contribution to this collection competitive. The matter of which offer to was given the office of Myer Bloom who of articles will be useful and interesting to accept loomed as a decision which could was away on research leave. We also other present or prospective physics just as easily end a career as start one. In started to worry about Catherine's next job couples and also to their colleagues, the end, diplomacy paid off and Catherine since, with only six months left at ITP and supervisors and administrators. emerged unscathed. Fortunately she still a new baby, we needed to cut down on considers both prospective employers to the commuting. Almost miraculously we be friends. heard that UBC would be nominating someone for an NSERC University The decision was to accept an offer from Research Fellow position. However we the ITP in Santa Barbara where the soon learned that this opportunity was Director was the Condensed Matter likely to be a long shot. When Catherine theorist, Bob Schrieffer. Not long approached the Chair of the hiring afterward, NSERC came through with a committee, she was told that the post-doctoral fellowship, which we used to department was looking for applicants negotiate an agreement with Santa Barbara "...w ith letters from Nobel Laureates," but and UBC so that Catherine could spend that it was OK for her to apply as long as several months each year working in she wouldn't be disappointed if she didn't Vancouver. This agreement turned out to get the nomination. be particularly important the following year when our daughter was born. The Our schedule for early September revolved transition from grad school to post-doc around childbirth classes, which we changed a trans-continental commute into attended, graduate Stat Mech and How we first got together as a physics a short North-South hop. Also the undergraduate Quantum Mechanics, which couple is a long and (for us) interesting difference between graduate and post-doc I was teaching, the Physics Colloquium, story which we have decided to defer to salaries was enough to cover our phone which I was organizing, and arranging for our memoirs. The most noteworthy event bills and to allow me to pay off the line of letters from Nobel Laureates. Catherine's for the purpose of this article is that we credit which had been steadily job talk was scheduled for September 11, were married in May 1983 at a small, accumulating at the bank. which fortuitously fell on the birthday of private ceremony in West Point Grey, our daughter, Ann Berlinsky Kallin (no Vancouver. Catherine was then a grad The ITP was a lively pace in 1984/85 and hyphen). Catherine's talk on the student in her third year at Harvard, and I quite hospitable to a young commuting Correlated Ring Exchange Theory of the was an established, i.e. tenured, Physics couple. We met a generation of post-docs Fractional Quantum Hall Effect was faculty member at UBC. At the time of who are now professors scattered across postponed for two weeks. The our marriage, Catherine was spending the North America and grad students who are department had great difficulty dealing semester at the Institute for Theoretical working their way through the ranks. One with Catherine’s application and, in the Physics (ITP) at UC Santa Barbara, where physics couple, who we did not even end, no one was nominated. Immediately her Ph.D. thesis supervisor, Bert Halperin, realise were a couple, were secretly after this decision was made, our friend was on sabbatical. When we returned married with a child being raised by Steve Girvin arrived to give a colloquium there and announced our new status at grandparents in England. It was a good on the quantum Hall effect, and I had the lunch on the Santa Barbara pier, Bert first surprise to everyone when we were invited pleasure of introducing his talk on the day chastised Catherine for making such an to a party where this was announced. after von Klitzing received the Nobel Prize important move without consulting her Steve Kivelson, now at UCLA, and Daniel for discovering the effect. supervisor and then ordered a round of Arovas, now at La Jolla, worked with champagne to celebrate. Catherine and Bob Schrieffer on the With no job prospects at UBC, we began "correlated ring exchange" theory of the scouring the market in earnest. After The following year Catherine completed FQHE, an original and intuitive alternative years of commuting we made the her thesis on cyclotron resonance and way of looking at Laughlin's wave conscious decision to market ourselves as electron-electron interactions in the two­ function, and I garnered thousands of a package. Wherever we went we dimensional electron gas. At that time the frequent flier miles with Western Airlines, interviewed as a couple with babe in arms. fractional quantum Hall effect was a hot which finally earned me a free ticket that This led to many hilarious situations, far topic and her thesis work was a useful I was never able to use because it arrived more than we have space to describe, but contribution toward understanding as we were leaving California. Most we did end up rating places on how well

122 Physics in Canada March/April 1996 they handled the special circumstances of We put Ann into day care because Yolanda travel together, it is frequently possible to our interviews - whether they arranged full and her family had moved to a farm in an bring the kid(s) along. We have done this schedules of independent interviews, what outlying suburb of Hamilton, and the drive many times - sometimes bringing our care they provided for Ann, and whether was just too long. McMaster has two day sitter, sometimes arranging on-site child sufficient time was allowed for nursing, care centres, one located on the campus care, and sometimes just "winging it" - and one, run by the McMaster Students rest, etc. In this regard, the two Canadian and Ann actually considers it a perk. She Union (MSU), a few blocks off campus. universities where we interviewed, has particularly enjoyed the weeks that we We never experienced the on-campus day Waterloo and McMaster, did very weil. By have spent over several summers at the care because we never made it to the top contrast, certain California universities Aspen Center for Physics where she has performed abysmally. Not only were they of the waiting list. However Ann was met many other physics kids. insensitive to the logistics of interviewing accepted into the MSU day care after only a few weeks. Although the Students a couple with an infant, but we were also Union sponsors the day care, the staff and Research leaves and sabbaticals present introduced to reverse nepotism, and more management are full-time professionals. In different problems. One problem is than one case of token interviews. On the fact, we found the quality of the care in coordinating them. Catherine had two other hand, we had one delightful this centre to be outstanding. Ann stayed leaves, one for 4 months at AT&T Bell interview at a U.S. national weapons lab, there through senior kindergarten. Labs in New Jersey (paid for in part by her which we were not so interested in, but Sloan Fellowship) and the other for 8 which treated us graciously, and we will Preschool child care is designed for the months at Cornell which was part of her always cherish the image of Ann with a convenience of working parents, but the first real sabbatical, for which Ann and I security badge pinned to her bootie. school system has not yet come to grips remained in Hamilton. Of course we with the concept of two-working-parent visited a lot, and, in the case of Cornell, I Ultimately we were very fortunate in families. As a result they start learned that by leaving Ithaca with Ann at finding positions at McMaster. I traded inconveniently late, end at a time when teaching for administration and took over most parents have to be at w ork, and are 3:00 a.m., I could drive back to Hamilton the Directorship of the Institute for closed on holidays and "professional in time to drop her off for school. Once, in Materials Research which Jim Morrison, a development days” when everything else 1991, we were able to coordinate a six chemist, had just relinquished; and the is open. In Ham ilton, the slack is taken up month leave together which we spent at Physics Department was happy to appoint by a service called First Base, which is run UBC and which allowed me to resurrect a Catherine to a tenure track Assistant by the YMCA and which provides before long-standing and extremely fruitful Professor position in Condensed Matter and after school child care and day care collaboration with Walter Hardy and, in Theory which they had been trying to fill when the schools are closed. This works fact, to bring Catherine into it too. Next for over a year. Catherine was the first well for younger children, but eventually year, for the first time, we will be able to woman in the physical sciences at they outgrow it. When we realised that take a full year research leave together at McMaster, and we have learned a lot from that was happening for Ann (toward the Stanford. that. Much of what we learned has now end of second grade), we hired Kathleen been incorporated into a mentoring who comes to our home every day in time program for junior faculty in Science and to meet Ann when she comes home from We are now in our 10th year at McMaster, Engineering which was instigated, at school. After a very short time, we found and we have had ample time to reflect on Catherine’s initiative, two years ago. that Kathleen was taking care of us too, the barriers and pitfalls which beset and she has since become an indispensable Physics couples, as well as some of the Having two real jobs in Hamilton imposed part of our family. Many years ago, benefits. We know we have been lucky, an unfamiliar stability on our lives. We Mildred Dresselhaus of MIT, a member of and we have a great appreciation for the spent a year finding a large house in one of the more famous physics couples, progress that has been made in mitigating downtown Hamilton, which we love but advised us that the key to success for the situations of women faculty and which will never be worth what we paid working couples was to get as much help couples. Programs such as parental leave, for it. Of central concern was child care as you can. (Millie's other tip for women which were not available to us, are crucial for Ann. Our child care in the U.S., which physicists was to have a good husband.) for making academic careers livable for had worked well, consisted, fortuitously, Money spent on child care, house care, or new parents. No mother should have to of a succession of three wives of male, just about any other kind of care that you lecture two weeks after her child's birth, Korean physics graduate students, each of would otherwise have to do yourself, is whom had two small boys of her own. money well spent. We have certainly nor should one highly qualified member of Our first child care in Hamilton was with a found this to be the case and have a couple have to languish in un- or under­ couple who took in several children in their benefitted greatly from the people who employment because of traditional home. Although they came highly have provided us with these services. prejudices about women or working recommended and are still used by other couples. Adequate child care facilities are physics parents, we found after a few One issue whch is closely related to child essential for working couples and for single days that we were uncomfortable with care and to balancing family and work is parents. A variety of types of child care them and quickly made different arrange­ that of travel, which can range from day are required for different stages of the ments. Having complete confidence in your trips, through conferences and committee children's and the parents' development. childcare providers is an absolute necessity work, to leaves and sabbaticals. Over the Although there has been much progress in for working parents, and even misplaced past ten years we have accumulated these matters over the past decade, the apprehension (as ours may have been) is considerable experience with all of these unacceptable. A newspaper ad led us to way has been slow and painful, and Yolanda (Ann always called her "my and more. A particularly complicated flexibility and imagination are still essential landa”), a young mother with two small situation is when both parents have to tools for survival. Equally well, the boys, who was happy to care for one child travel at the same time independently. In experience of others can be a useful guide. in her home. Yolanda loved having Ann, those cases and in the absence of nearby The advice that we received over a decade since she very much wanted a daughter. grandparents, having the possibility of ago from Millie Dresselhaus has proven By the time that Ann moved on to day overnight child care, which for us was invaluable for us, and we hope that some care, Yolanda had four sons, but still no provided by Yolanda and later by Kathleen, of the anecdotes in this article will be of daughter. is essential. Of course when both parents use to future physics couples.

La Physique au Canada mars à avril 1996 123 PHYSICS FAMILY PROFILE: JENIFER AND MICHAEL THEWALT

When we were invited to submit an article a new environment, with new people, and and whose parents live nearby, wanted to to this special issue of Physics in Canada embarking on new research projects. move away from Vancouver. However, it was impossible for us to ignore the Added to this was the inevitable worry creating a position for oneself is never a opportunity. Besides being one of the few about Eric’s well-being: he was looked straightforward process and creating such (two?) married couples in Canada to hold after by a lovely and caring young nanny a position spanning faculties is even more faculty appointments in Physics during the day, but no matter how difficult. In this case, though, the process Departments, the guest editor of the issue exemplary the person, changes in child­ was facilitated by the Head of the Division is none other than Jenifer's sister Ann care arrangements are always of Dermatology, David McLean, who McMillan. Any sense of professional accompanied by some anxiety. Evenings enthusiastically supports links between responsibility prompting us to write the were fully occupied with Eric, an active Medicine and 'hard science'. Similarly article has thus been magnified enormously and captivating toddler who had the habit supportive was the Head of the Physics by sisterly duty. As this is primarily the of being wakeful between the hours of one Department at UBC, Brian Turrell, who story of Jenifer’s attempts to seek and three a.m. This habit was broken out feels that a Physics approach can be permanent academic employment since the of necessity shortly after I started work: invaluable for problems outside traditional early 1990's, the article will be written Mike’s membership on the condensed Physics, and who also feels that the from her perspective. The 'women's matter NSERC grant selection committee discipline of Physics can benefit by being issue’ this article will address is that of entailed a week-long sojourn in Ottawa in perceived as useful by researchers in other targeted appointments, in particular February, during which I managed to disciplines. In the summer of 1993 the spousal appointments. Many readers may convince Eric of the value of uninterrupted Division of Dermatology took the initial have well-formed opinions about this issue: slumber. Mike continued to have step, in the form of a five-year plan entry perhaps this article will provoke some tremendous committee work for a membrane biophysicist, toward philosophical reassessments. responsibilities during Eric's early years, an creating a position for which my skills aspect of professorial life he relished would be ideal. Under Brian Turrell's somewhat less than his research. direction, the UBC Physics department's Travelling would take its toll, he often Committee on Initial Appointments returned not only tired but viral, to be evaluated my WFA research proposal, greeted by a fatigued 'Physics widow' who solicited letters of reference, asked me to had held the fort in his absence. give a colloquium and interviewed me. In other words I received fair treatment, This unbalanced life-style persisted until a despite the complication that UBC had chance remark by one of my UBC imposed a hiring freeze which extended colleagues raised my consciousness. even to the subsidized WFA program. This Asked where Mike was, I replied that he point, however, became moot once the was in Ottawa, serving on the (now Physics department discussed whether or defunct) NSERC Women's Faculty Award not to support my WFA nomination. (WFA) selection committee. This Objections were raised because the prompted the ironic realization that Mike position had not been advertised. How was helping distribute jobs to my peers one would go about advertising a position while I was 'at home watching the kid'! under a university hiring freeze was not The invitation to write this family profile clear, but, nevertheless, the department came in the summer of 1995, a time of Overcoming my natural tendency to finish decided not to support the application. considerable turmoil in our careers - I will experimental studies but leave until an This was a disappointing turn of events, elaborate on this later. First, though, I will undefined 'later' the writing up and but my nomination went to Ottawa summarize our personal and professional publishing of results, I began to heave my anyway, with the sole support of the UBC backgrounds. Married for 1 3 years, we met CV out of the doldrums, with the aim of Dept, of Medicine. in 1981 when I was a graduate student in eventually applying for a WFA. A gentle Chemistry at Simon Fraser University and suggestion from Myer Bloom that I Thus ended six weeks of the most grueling Mike was a young Assistant Professor of concentrate on forming links with other effort I can remember. Mike had had two Physics and NSERC University Research departments, given my chequered Physics week-long trips to Japan during that time, Fellow. Following a 10-month court ship, we past, was duly noted. My pedigree and I operated on 3-4 hours of sleep, married the following summer, having consists of an undergraduate degree in hiring baby-sitting in shifts, and becoming neglected to develop detailed plans for our Biophysics and a doctorate in Chemistry, more and more frazzled. The excitement future careers. Mike had no real need to followed by postdoctoral work in a Physics of working to a deadline, and having the plan, having already achieved international lab. Physics department traditionalists still potential to generate a permanent position, recognition in his area of experimental often frown on expertise outside 'pure' was enough to sustain this fairly short­ physics: low-temperature luminescence of Physics, regarding such knowledge as term effort. Over the long term it would semiconductors. He worked single-mindedly contaminating rather than enhancing a have been painful to see the effects on and enthusiastically, developing ever better researcher. Other departments have the Eric, who was, no doubt, being neglected spectroscopic methods to further the complementary view, by and large. Since by his mom: small cracks began to appear understanding of the optical properties of career advice from Myer was rare (he in his demeanor, his musical education semiconducting materials. On the other prefers a non-directive supervisory stopped progressing with the customary hand I was now geographically tethered: approach), I took it seriously, especially rapidity, and he seemed generally less there are just two universities in the Lower since interdisciplinary work dovetailed with content. This intense work paid off in one Mainland of British Columbia. Fortunately, my preferences. A fledgling collaboration sense however: for Mike it was concrete one of the world's leading research groups with Neil Kitson in the Division of evidence of my ambition, and he became in my area, NMR applied to membranes, is Dermatology at UBC, studying the physical more fully appreciative of my desire for an located in the Physics Department at the properties of skin lipids, was nurtured and academic career. University of British Columbia under the gradually began yielding papers. intellectual umbrella of Myer Bloom, In January, 1994, the WFA committee currently Emeritus Professor. I obtained an Neil’s encouragement included vague met. Mike had tried unsuccessfully to NSERC postdoctoral fellowship to go across references to faculty positions in resign from the committee once it became town following my Ph.D., arrived at UBC Dermatology, and the following year - clear that my nomination was on its way five months pregnant, and took advantage 1993 - I hatched the scheme of creating a to Ottawa. This sort of committee work is of the maternity leave provisions of the WFA position jointly between Physics and largely thankless: like the peer review NSERC awards to spend one full year at Medicine at UBC. Neither Mike, whose lab process it relies on the continuing home with our son Eric in 1988. was by now fully established, and who generosity and community-mindedness of The first years back in the lab were, in held an NSERC Industrial Research Chair at scientists in Canada. Mike was left in the retrospect, challenging ones. Initially there SFU absolving him from teaching for five awkward position of standing anxiously was some i ·.security involved with being in years, nor I, who loved my work at UBC outside in the hall for 20 minutes while the

124 Physics in Canada March/April 996 committee discussed my application. As a was extensive discussion in the Physics Factually correct but highly selective in side remark: the ethics of the committee Department about the situation. Prof. content, the interview was insulting and were flawless and Mike was given no hint Frindt, department chair, sent a memo to biased. For example, throughout I was of the fate of my application. This rather his faculty advising them of the problem, referred to as 'Mrs. Thewalt' - certainly not inhuman adherence to the rules was most emphasizing Mike's central role in the the appropriate title to use in matters unsatisfactory for me - while Mike was in department's success in raising research relating to my career. Resisting the urge Ottawa, I had had the usual single parent funds, and outlining my background, to respond to this attack on SFU’s experience made orders of magnitude more appending my WFA research proposal and character, I tried to forget that the incident unpleasant by the odd situation. the external reviews thereof. The Dean had happened. I was able to do this Psychologically it was difficult having my met with the Department of Physics as a easily, as I was preparing to give an invited spouse in a perceived position of power whole to discuss the establishment of the talk at a Gordon Conference the following over my career and there was an inevitable joint appointment and also held discussions week. The day before I left for the build-up of resentment as a result. At the with the Director of the IMBB. By secret conference, however, I happened to time of my nomination I was one year ballot in which Mike did not participate, a encounter an acquaintance who had heard beyond the recommended 'time since decision was made in favour of pursuing the radio show but who had not connected Ph.D.' for the WFA awards, and was thus the idea of creating a position for which I me with the content: embarrassment of not overly optimistic about the outcome. would be considered. The decision was both parties was kept to a minimum, but Six uncomfortable weeks passed before I not unanimous: some members of the my anger level increased as I realised that heard that I had been unsuccessful, and department felt that the exercise was one my newly-minted public reputation was even though the news was not in which pragmatism was completely significantly less flattering than I would unexpected, it was still a blow. Self­ outweighing 'principle'. In the end, the have preferred. Over the next few weeks doubt, self-blame and feelings of rejection department made the courageous choice to there was a flurry of media articles in the were prevalent mental states for some proceed with their evaluation of me, clearly local papers concerning my spousal time following the announcement: there labelling the potential job a spousal appointment. The headline 'SFU Denies was a sense of doors closing permanently - appointment. Nepotism' enhanced the vocabulary of the a frustrating scenario for me at the age of local tabloid's readership at the same time 36. These feelings were compounded by An appointments committee was formed as it gave unwarranted negative publicity our continuing failure to conceive a second at this stage, letters of reference were to the university. Finally, the university child. The unadvertised creation of a solicited in the usual manner, and I was papers wrote their pieces about the issue, position for another young physicist at interviewed on May 1, 1995 by both the and the dust settled. UBC in the late spring was a further source Physics Department and the IMBB. The of frustration, as was the decision by the interview did not feel in any way watered Emotional fall-out takes more time, but UBC Physics department to advertise for a down due to the 'spousal' nature of the when I took up my appointment in WFA position that year. Meanwhile Mike position: I presented two one-hour talks, September I felt generally warmly was suffering in sympathy, and the death a teaching demonstration and a research welcomed and comfortable. Notice of his father in June compounded his grief. seminar, met with members of both received in October that the collaborative departments, and was thoroughly grant had been awarded was most exhausted at the end of the day. Monday welcome, and gave me a greater sense of In contrast, my research effort was going May 1st was also the deadline for NSERC autonomy, as did my recent appointment well, with the first comprehensive papers Collaborative Project Grant proposals to as Adjunct Professor of Medicine at UBC. from the Dermatology collaboration being arrive in Ottawa, and I had been busy up Myer Bloom has continued to be an accepted for publication, and with an until the Friday before putting the finishing important source of support, and Mike has invitation to speak at the annual meeting touches on a grant application. (This managed to navigate the minefield of of the C A P. in Regina. Mike spoke at the process was a little frustrating since I had playing the dual roles of husband and same meeting, and for the first time we discovered rather late that I was ineligible colleague with admirable dexterity. As far travelled together on a joint business trip. to apply for such a grant due to my lack at as being a two-career family goes, I feel I stayed only two days, then left to get that time of a firm offer of appointment - exceptionally fortunate in two respects: back to Eric and to stop the accumulation the application instead was submitted in Mike’s preferred method of relaxation after of non deductible extra child-care costs. the names of my collaborators.) work involves cooking, and Eric's live-in It was a good trip: I returned feeling a nanny, Petra Persch, is without peer. sense of renewed energy due to the Time passed, as one member of the positive comments my talk had received. appointments committee was away. The current over-supply of highly qualified In addition, I had had the chance to catch When the committee members were people searching for university faculty up with my sister Ann, always an reunited, they wrote a report positions at a time when university encouraging and understanding figure. recommending me for the position. The budgets are being reduced is regrettable members of the IMBB had voted and resentment of holders of targeted Later that summer, Mike, never one to unanimously in favour - a much- appointments of one kind or another is tolerate sub-optimal situations unless given appreciated vote of confidence. Finally, inevitable. In an ideal world, no-one would no choice, began considering career the Physics Department ratification vote be under employed. Spousal appointments options for us. A casual comment here was held, and achieved in excess of the are not a new phenomenon. Our situation and there at SFU regarding my lack of a required two thirds majority. SFU's Board was unusual in that Mike already had a permanent position and the potential of Governors approved my appointment in position when my spousal appointment necessity for us to move away from late July, and my employment contract was created, but the end result is identical. Vancouver began a series of events whose was signed soon after. This would Again, in an ideal world, jobs suiting both velocity and acceleration surprised even normally signal the 'Happy Ending' of this partners in a marriage would exist Mike. I was fortunate in that my article. automatically within a confined interdisciplinary background fitted in well geographical area. This is obviously an with Dean of Science Colin Jones’ plans to Instead, events took a turn into the arena impossible wish. Some might say that one enhance cross-disciplinary research: an of academic pulp fiction. One day in mid­ partner should sacrifice their career for the August, while I was making measurements attractive area for graduate students. other's, and in fact we feel that I have Over the fall months of 1994 informal at UBC, one of my colleagues came in and done this in the past to some extent, discussions were held among various took me aside. He told me that he had although 'sacrifice' is too strong a word. departmental chairs and the Dean of heard that I had been the subject of a talk Certainly, the combination of academic Science regarding the possibility of radio program that morning. Stunned, I career and child-rearing is challenging for creating a position for me at SFU. These inquired further, and was told that a both parents. In our case, we feel that the discussions led to a proposal by Colin to particular retired SFU Physics professor establish a targeted joint appointment had taken his ’principled’ objections to my slower start to my career, which will between the Department of Physics and appointment to the airwaves. My name inevitably have a big impact on my lifetime the Institute of Molecular Biology and had been mentioned, along with Mike's. A earnings, is a reasonable price to pay for Biochemistry (IMBB). This was not a few phone calls turned up a copy of the the lifetime privilege of having children. decision that was made casually: there tape, which I listened to that night.

La Physique au Canada mars à avril 1996 125 MOVE BEYOND THE UNCERTAINTY PRINCIPLE IN FAMILY AND CAREER

by Ying Qi, Atmospheric Environment Service, 4905 Dufferin St., Downsview, Onta'io, M3H 5T4

In physics and mathematics, there is a family life. Each time I had a vacation, used to the language, foods, etc. in well-known uncertainty principle, which they invited me to go home so sincerely Canada as soon as possible. We examined says "the precise measurements of time that I could not turn down invitations from again whether we were under control of and frequency are fundamentally them until I left China to Canada, even the uncertainty principle incompatible, since frequency cannot be after I was married. They always let me measured instantaneously". In our life, feel part of the happiest family no matter A few months after we came to Canada, career and family, particularly for a what happened. Their love and care made Jingnan got a position as a research woman, are often in conflict with each me feel that I already had a happy family. assistant at the Department of Earth and other. A career woman may be successful I would not regret spending the rest of my Atmospheric Science, York University. We at a cost to her family life. In this sense, whole life on my career. continued our common interest in family and career seem also to observe the boundary-layer meteorology and mesoscale uncertainty principle. It is hard for a MARRIED meteorology. In the meantime, realized woman to have both of them in perfect that it would be more helpful both to Eight years ago, because of common harmony! Canada and to my career if I would make interest in boundary-layer meteorology, I a direct contribution to Canadian met Jingnan by chance. He was a lecturer atmospheric research science since I lived at Nanjing Institute and I was a graduate. in Canada. Therefore, I further expanded Jingnan is a person who likes to talk, my research domain and developed my particularly in the language of meteorology. two new areas. One is joining the He loves his career, too. However, research community for a new Canadian different from me, he also wanted to state-of-the-art mesoscale numerical model develop a family not only his career. MC2. The other is exploring the Moreover, he thought that common applications of a new mathematical tool, interest was one of the bases of a happy wavelet analysis, to meteorological and air family in addition to love, understanding quality research. The latter is quite a and care. During each meeting, although though topic since wavelet analysis is atmospheric science was always the topic described by modern functional of the meeting, we came to understand mathematical language. To achieve the each other more and more Jingnan's objectives, I have not taken any vacations personality influenced me and reminded me I am an atmospheric scientist and now since I came to Canada in December, that I would lack something valuable in my work at Atmospheric Environment Service 1993. It was our happy and relaxed family life if I kept focussing on my career. (AES), Environment Canada as a contract talk that often released me from intense Finally, I found our meetings were not only research scientist. I have a simple family, work. We both enjoy the life style. In the for meteorological conversation but also a my husband Jingnan Zhou and me. My mingling of intense work and happy family part of my life which could not be lost. husband is also an atmospheric scientist life, I have made some very encouraging We got married one and half years later. and now works as a research assistant at progress in my new research areas. I have the Department of Earth and Atmospheric modified and improved one of the After we were married, we did not want a Science, York University. Actually, a three important schemes in the MC2 model and baby as a normal family would because I person fam ily would be more exact as w e have successfully applied wavelet analysis was still afraid of the uncertainty principle. will soon have a new member to come in in meteorology and air quality research. I However, I was not alone any more. the world — our unborn baby. I once thank Air Quality Research Branch at AES When I was a Ph.D graduate at Nanjing believed in and was bound up by the for supporting my w ork after the NSERC University, Jingnan and I had a chance to uncertainty principle in considering career visiting fellowship was finished. work in the same computer terminal room and family, but finally I have moved as he had a cooperative program with beyond the influence of the principle in my Over the past two years, we have Nanjing University at that time. When I life. experienced a lot and improved ourselves was a postdoctoral fellow at Institute of a lot, too. We surprisingly find that we Mechanics, Chinese Academy of Sciences, TO BE ALONE can really comfortably balance our careers Jingnan was a visiting researcher at the and family life. Perhaps experience has Before I met Jingnan 8 years ago, I had same institute so we again, had a chance given us the ability. Whatever, we have decided to sacrifice my family life to to share the same office. Frankly, Jingnan enough confidence now to start a normal develop my career in atmospheric made much more contribution than I did to family life during our continued pursuit for sciences. When I was a child, I dreamed create our small but comfortable family. careers in atmospheric sciences. We are of being a great scientist in the world. Perhaps, in a certain sense, I owed him a ready to welcome our baby into our lives. Gradually, I realized that a woman with a lot. While we enjoyed our special family, Finally, I realize that I have moved beyond normal family had a very difficult time to Jingnan got an excellent young professor that uncertainty principle. Moreover, in a be successful in her career in science. As foundation award in Jiangsu province. I sense, I feel that the relationship between a matter of fact, many famous scientists, got my Ph.D and published more than 15 a family and career seems to be more like not only women but also men are single. papers and 1 book about my own research the relationship between water and a boat: In China, at least half or even more of the achievements. Shortly after that I was water can carry a boat but water can also female fellows of the Chinese Academy of awarded the highest category of capsize a boat. Family life may be in Sciences were single before 1989. These Changwang Tu's Young Meteorologist conflict with career, sometimes apparently facts reminded me always of the existence Prize by the Chinese Meteorological controlled by the uncertainty principle, but of the uncertainty principle for family and Society. a happy family life can also become a career. I did not dare to expect not to be source of inspiration for one’s career life. bound by the principle like Mrs. Curie , MOVE BEYOND THE UNCERTAINTY Development of one's career can thus be because somehow, I always believed in PRINCIPLE greatly accelerated because of the science much more than in luck. In December 1993, I came to Canada as existence of a happy family. an NSERC visiting fellow, accompanied by Another reason for my decision to sacrifice Jingnan. We began to create our new I should be thankful to Jingnan. He makes my own family life to make my career family and career environment. Living me own a complete life! successful was probably the love of my abroad provided us more experience. We parents, elder sister and brother. They had more things to face and to deal with in always supported me to develop my career each of our careers while we had to get

126 Physics in Canada March/April 1996 Books Received / Livres reçus

The following books have been received for $250 (he) (Editor's note: This is a truly occurrences and activities such as the review. Readers a re invited to w rite reviews, exceptional book. I expect to get many buzzing of bees, the spin on tennis balls, and in English or French, of books of interest to requests for this book and I've decided NOT the causes of lightning, as well as on certain them. Books may be requested from the to honour requests on a first-come basis as is aspects of science fiction, such as the book review editor André Roberge by email usually the case. Instead, I ask the potential theoretical flaw in Wells' Invisible Man. As at [email protected] or at reviewers to provide a rationale as to why well, the thorough solutions provided are Depart ment of Physics, Laurentian they should get to review this volume and easy to comprehend and are not replete with U niversity, Sudbury, Ontario, P3E 2C6. will use those rationales to decide who will the technical jargon abundant in puzzle Tel: (705) 675-1 151, ext. 2234 . FAX: have the honour of reviewing this book.) books of a similar nature. However, the most (705) 675-4868. Please check out our intriguing questions are found in the final n e w W e b site at http:// Core Level Spectroscopies for Magnetic chapter of "unsolved" riddles, which involve www.laurentian.ca/www/physics/CAP/ and Phenomena; Theory and Experiment, questions that remain unanswered, or have give us your comments. edited by P.S. Bagus, G. Pacchioni and complex solutions. The majority of the F. Parmigiani, Plenum, 1 995, pp:viii + 274, puzzles are accompanied by comical Les livres suivants nous sont parvenus pour ISBN 0-306-45006-2; Price:$ 89.50 illustrations by Suparno Chaudhuri, which la critique qui peut être faite en anglais ou en enhance the laid-back style of the book and français. Si vous êtes intéressés de nous Lorentzian Wormholes - From Einstein to reinforce its appeal to lay persons. It is communiquer une revue critique sur un Hawking, by M. Visser, AIPPress, 1 995, pp: unfort unate that the majorit y of solutions a re ouvrage en particulier, vous êtes invités à x x v + 412, ISBN 1-5 6 396-394-9; not enhanced with figures and illustrations, vous mettre en rapport avec le responsable QC173.6.V57 Price: ? which greatly help in understanding the de la critique des livres, André Roberge par underlying physical principles behind a courier électronique via Nuclear Decay Modes, edited by D.N. specific problem. [email protected] ou au: Poenaru, I0P, 1996, pp: xv + 577, ISBN Département de physique, Université 0-7503-0338-7; Price: $320 (he) In all, Riddles in Your Teacup is a delightful Laurentienne, Sudbury, Ontario, P3C 2C6. foray into the deciphering of puzzles and Tel: (705) 675-1 1 51, poste 2234. Optical-Thermal Response of com mon occurrences found in everyday life, Télécopieur: (705) 675-4868 S.V.P. allez Laser-Irradiated Tissue, edited by A.J. Welch lacking, however, the jargon and technical visiter notre page W3 à http:// and M.J.C. van Gemert, Plenum, 1 995, pp: explanations that do not appeal to the young www.laurentian.ca/www/physics/CAP/et xxvi + 925, ISBN 0-306-44926-9; and to lay persons. The price of $22 U. S., or faites-nous part de vos commentaires. Q H 6 4 2 .0 6 5 Price: $1 39 .50 (he) about $30 Canadian is too steep for a paperback book of only 173 pages; GENERAL INTEREST Structural ElectronCrystallography, by D.L. nonetheless, the book is an ideal choice for Dorset, Plenum, 1995, pp:xiii + 452, ISBN high school libraries, and may be added as an The Demon-Haunted World, by C. Sagan, 0-306-45049-6; Price: $ 69.50 (he) interesting supplement to traditional high 1 995,pp:xviii + 457JSBN0-394-5351 2-X; school physics texts. It is recommended, Q175.S21 5, Price: $35.95 (Can) Theory and Application of Laser Chemical however, to anyone with an interest in Vapor Deposition, by J. Mazumder and science, because, as Dr. Paul Davies aptly states in the foreword, "all scientists are Glimpsing Reality: Ideas in Physics and the A. Kar, Plenum, 1995, pp: xii + 395, ISBN young at heart". Link to Biology, edited by P. Buckley and F. 0-306-44936-6; TS695.M39Price: $89.50 D. Peat, University of Toronto Press, 1 996, (he) pp: xv+199, ISBN 0-8 0 2 0 -0 5 7 5 6 (he) Samir C. Grover 1405 Bortolotti Crescent 0 8020 6994-0(pbk);QC1 5.B83Price:$55 EN FRANÇAIS (he), $19.95 (pbk) Ottawa, Ontario L'Aventure de la fusion nucléaire, par K1B 5C1 M. Trépanier, Boréal, 1995, pp:303, ISBN How Life Begins; the Science of Life in the Of One Mind; The Collectivization of W om b, by C. Vaughan, Times Books, 1996, 2-89052-527-9; HD9698.C22T73, Prix: 24.95$ (pbk) Science, par J. M. Ziman, AIP Press, pp:xiv f 290, ISBN 0-81 2 9-2103-8; pp:xvii + 4 0 6 , ISBN 1-56396-065-6; RG525.V38, Price: $32 (Can, he) Book Reviews/ QC1 6.Z56A3 Prix: 29,95 $US (couverture The Physics Quick Reference Guide by E. R. cartonnée). Cohen, AIP Press, 1996, pp: x + 209, ISBN Revues des livres John Ziman n'est plus qu’un ex-physicien 1-56396-143-1, QC61 .C65 (spiral bound) Riddles in Your Teacup, 2nd edition, by ayant trouvé refuge, après une carrière scientifique fructueuse, au département A Tour of the Calculus, by D. Berlinski, P. Ghose and D. Home, ΙΟΡ Publishing, d'études sociales et économiques de Pantheon, 1995, pp: xvii + 331, ISBN 1 994, pp: xiii + 1 73, ISBN 0-7503-0275-5; l’Imperial College à Londres. Du moins, 0-679 42645-0; QA303.B488, Price: Price $22 U.S. (pbk) est-ce ainsi qu'il se présente, un peu à la $3 8.50 (Can, he) In this revised and enlarged second edition blague, dans le dernier d'une trentaine d'essais non-techniques rassemblés par les Universe Down to Earth, by N. de Grasse of Riddles in Your Teacup, the authors, Presses de l'American Institute of Physics Tyson, Columbia University Press, 1995, pp: P. Ghose and D. Home, have collected and dans le cadrede la série "M asters of Modem x iv + 2 7 7 , ISBN 0-231-07561-8; have given brief scientific explanations for Physics". Rares sont ceux qui possèdent la QB982.T97, Price: $14.95 (pbk) numerous examples of natural phenomena and commonplace activities. This book, lucidité de longues années de pratique co n ju g u é e avec une compréhension Wonders of the Ancient World, National based on the authors' regular columns in théoriqueapprofondiedelasociologiepropre Geographic Society, 1994, pp:304, ISBN Indian popular science magazines and aux communautés scientifiques et des 0-87044-982-6; CB311 .W63, Pnce: $49 (Can, he) newspapers, is intended for the young with a high school background in science. mécanismes gérant l'évolution de la connaissance. Trop souvent, les GRADUATE TEXTS AND PROCEEDINGS The book is divided into seven chapters of commentaires et discours s'inscrivent dans deux traditions déficientes: celles du Chemical Kinetics and Catalysis, by R. A. van questions and puzzles with solutions, scientifique improvisé sociologue qui livre Santenand J.W. Niemantsverdriet, Plenum, followed by a chapter of unanswered une image myope et navrante de son uni vers 1995, pp:xi + 280, ISBN 0-306-45027-5; problems. The grouping of questions is not familier ou du philosophe qui n'a de la Price: $6 9.50 (he) based on a traditional curricular classification of topics in physics, but is sciencequ'uneconnaissance livresque bien souvent dépassée ou tout bonnement The Collected W orksof P.A.M. Dirac 1924 rather based on the locations where a puzzle fausse. Ziman, heureusement, fait partiede 1948, edited by R.H. Dalitz, Cambridge can be faced, such as in the kitchen, on the l'élite des commentateurs de la vie University Press, 1995, pp:xxiii + 1 310, playground, or in popular films and novels. scientifique et évite les écueils habituels. ISBN 0 521-36231-8; QC21.2.D57, Price: Questions are posed on common

La Physique au Canada mars à avril 1996 127 Of One Mind: The Collectivization of motor development. Henry Ford’s The text is very well edited. I found only one Science, le tout dernier recueil de John contribution tothecarindustry isoutlined in slight error of vocabulary viz; on p. 45, the Ziman apporte donc une profondeur a five-page section. The Wright brothers expression electric battery is used when rafraîchissante aux discussions entourant le (Orville and Wilbur) also get a special electric cell is intended. Too, I was amused pourquoi et le comment du processus de la four-page sketch of their contribution to the by a line in discussing some of Graham Bell’s découverte. L’auteur n'hésite pas un instant development of airplanes. The historical work; "While vacationing at the Bell home in à replacer dans une dynamique sociale les developments of modern day materials is Ontario, Canada ...", (p. 54). comportement des chercheurs et l'avancée found in Chapter 5, A World of New des connaissances par la recherche. Ceci est M a te ria ls. It begins with the early works of The illustrations are indeed excellent and the particulièrement vrai dans les portraits about 1850 describing attempts to make write-ups are very well done! It would be critiques qu'il trace de quelques grands "rubber" into a "useful" product. Included is excellent background material for use as physicienstelsEinstein, Dysonet Landau, et an interesting look at the story of the new complementary material especially for p lu s encore d a n s so n analyse des plastics and alloys. Charles Goodyear university science lectures. On the other changements fondamentaux qui ont (rubber) and Leo Baekeland (Bakelité) have hand, since the work contains very little transform é la recherche mais aussi la special sub-sections devoted to their work. mathematics, anyone with a modicum of communauté de chercheurs depuis plus de Capturing the Image, traces out the learning can profit from its reading. I do 50 ans. development of photography. Special believe that it could be a source of inserts look at the life and contributions of inspiration, for students of all ages. Thus I On ne peut que regretter que les William Henry Fox Talbot, George Eastman, d o believe that INVENTORS AND bouleversementsdesdernièresannéesdans and Edwin Land. Strangely, though, there is DISCOVERERS, Changing OurWorld should la communauté scientifique mondiale no mention of present-day digitization of be found in all libraries. échappent à l'analyse lucide de Ziman pictorial elements - which would bring the puisque la plupart des essais rassemblés ici reader to the very latest advancement sin the Gérard Hébert, Emeritus furent écrits durant la première moitié des field of photography. The chapter entitled Dept of Phys. & Astron. années 1980. Avec la réduction marquée Messages by Wireless traces out the early York University des fonds pour les grands projets et la days of telegraphy, radio, radar, television. A fermeture de grands laboratoires de three-pagebiog raphyof G uglielmo Marconi, LONG-RANGE CASIMIR FORCES, THEORY recherche industrielle, il n'est pascertainque and a four-page description of the AND RECENT EXPERIMENTS ON ATOMIC la collecti visât ion de la science, qui just ifiele contributions of Bell Laboratories scientists SYSTEMS, edited by Frank S. Levin, David titre du recueil, demeure la voie du futur en - which include such notables as Walter A. Micha, Plenum, Press, 1993, ppxv + 357. science. Sa discussion des autres aspects Brattain, John Bardeen, William Shockley, ISBN 0-306-44385-6; QC680.L63. Price: de la vie des scientifiques demeure valide, and Clinton Davisson - are indeed very $75.00 (hc). toutefois, que ce soit le côté néfaste du interesting sub-sections of this chapter. jugement par les pairs, les jeux de pouvoirs et Power Particles deals mainly with atomic Forty-eightyearsago, Casimir, motivated by de reconnaissance, le refus par les energy. A special section of the chapter is experimental puzzles on the stability of scientifiques d'assumer leurs devoted to the works of Ernest O. Lawrence colloids showed that parallel uncharged responsabilités, etc. of cyclotron fame. Another sub-section is metal plates were attracted by a force per devoted to the contributions of Enrico Fermi, unit area equal to within a numerical Il n'est pas certain que tout physicien se the great nuclear physicist. Modern day constant to the reciprocal of the distance reconnaîtra dans le portrait de la science et inventions are based in large part on between them to the forth power times de la communauté scientifique que trace computer chips, the subject of Chapter 9. Planck's constant and the speed of light. For John Ziman. Une chose est sûre, toutefois, The history takes us from the early days of other symmetric shapes the force can be l'image nuancéeet cornplexedécritedansce the abacus to the modern age of computers. repulsive. It is not obvious intuitively why livre ne peut que nous amener à réfléchir sur A special section of the chapter is devoted to theeffect isproportionaltothespeed of light nous mêmes, nos interactions avec nos John von Neumann, a name almost and how to predict the sign of the effect. collègues et avec la société en générale, et à synonymous with computer design. The Experimentally this effect, and analogous décou v ri r que plusieursdes mythes que nous penultimate chapter is entitled Engineering effects all due to retarded interactions, have entretenons sur notre communauté ne Life. Here we find reference to the work of been checked experimentally to the order of trouvent guère contact avec la réalité. Jenner, Pasteur, Lister, and Paul Ehrlich. So ten percent. too are discussed the works of Fleming, of Normand Mousseau Selmán A. Waksman, and of Banting and It is the purpose of this book to elucidate Département de physique Best, and Jean- François Boréi. A special recent attempts to measure Casimir forces Université de Montréal sectioninthischapterisdevoted to the work to high accuracy in an atomic physics of William J . Koff, a pioneer in the field of experiment. This f irst chapter by Spruch is a INVENTORS AND DISCOVERERS, Changing artificial organs. The text proper ends with delightful tutorial, clear, discursive, a musing OurWorld, NationalGeographicSoc., 1988, Technology of Tomorrow. It begins w ith a on the physical origin of the Casimir effects p p 320. ISBN 0 -8 7 0 4 4 -7 5 1 -3 ; discussion of the development of and much more. The most sensitive method 0-87044-752-1 deluxealk. paper; T 18.157. superconductors, then goes on to describe to study the Casimir forces appears to be in Price: $ 21.95hc; 29.95 deluxe, hc. some modern-day applications. There is also very high precision experiments on Rydberg a description of the potential of DNA studies States of Helium. The introduction to this eleven chapter opus from location of human genes to the plans indicates that the scope of the book for the analysis of the bases' sequencing. Lundeendescribes beautiful experiments on presumes to begin at the beginning of the the n=10 fine structure of Helium. The 18t h century and ends w it hsome indicat ions The main body of the text is followed by a measurements, accurate to better than a of promises of the Technology of Tomorrow. section about the authors, an important part kilohertz, measure the small Casimir energy The Power of Steam uses an historical of the book, since INVENTORS AND contributionstoaprecisionof 10 percent. In approach dating from about 1690 (Denis DISCOVERERS, Changing Our World, is a order to determine the Casimir energies it is Papin of France). A one page insert outlines multi-author publication. A second section necessary to know all other energy the work of George and Robert Stephenson, on Acknowledgments, and a third on contributions including relativistic and and a two-page spread is dedicated to the Illustration Credits, precedes a six-page quantum electromagnetic to a very high contributions of Robert Fulton, one of the three-column per page Index. The special accuracy. Drake, who calculates the early successful developers of the inserts, which g ive usa short biography of a non-relativistic energies to better than steamboat. Chapter 3 takes us on an number of inventors and developers, are fourteen figures and also the relativistic and historical trip into The Age of Electricity easy to spot as to their beginning, but Lamb shift contributions, presents clearly beginning with the early work of the Volta. sometimes the end of the inserts are a little the procedures and results of this remarkable Special sub-sectionsaredevoted to the work harder to locate. The typescript is almost the numerical work. Drachmán, in the spirit of of Thomas Edison, Nikola Tesla, and Graham same as that of the main body, thus if you Rydberg, calculates the energies of these Bell. On Wheels & WingsXakes on the story are reading the main text, it is sometimes a states in perturbation theory. Although not of the motorcars and airplanes. The famed little bothersome to have to hunt to find its as accurate as the numerical calculation, his Gottlieb Daimler and Carl Benz get a continuation! results are perhaps easier to interpret three-page spread of their work in car and physically and are sufficiently accurate for

128 Physics in Canada March/April 1996 the existing experiment. Finally Sucher and author's own philosophical and political on the earth. He argues that inventorying Feinberg present a more "high brow" view s. potentially-impacting bodies is "...prudent, account of the theoretical foundations. it's good science, and it doesn't cost The author begins by examining "... the much.". But he argues strongly against Much of this book is a joy to read - so put widespread claims made over all of human the immediate development of systems to down your Christie mystery and pick up your history that our world and our species are deflect such bodies, because of their "Casimir Forces". unique, and even central to the workings immense potential for misuse, by and purpose of the Cosmos." He deflecting otherwise near-missing bodies to Dr. F.W. Dalby describes how these claims have gradually hit the Earth. He argues that it's better to UBC yielded to modern scientific views of our wait - and take the roughly 1 in 1000 risk unprivileged place in a naturalistic cosmos of a catastrophic impact - until humanity is QUANTUM MECHANICS, AN and our essential similarity to other (hopefully) more unified in a century or INTRODUCTION FOR DEVICE PHYSICISTS species. Readers of differing philosophical two. The author forecasts that humanity AND ELECTRICAL ENGINEERS, by or religious persuasions might take issue may have a well-developed, unified, and D.K. Ferry, IOP, 1995, pp: ix + 288. ISBN with the author's strongly articulated environmentally benign Earth-wide 0-7503-0327-1 (he) 0-7503-0328-X (pbk). humanistic views here, but I found these civilization by the 22nd century. Assuming interesting and quite compelling, though this, he argues that we, and indeed all This book uses a nontri vial approach to teach somewhat disconnected from the civilizations at comparable stages of quantum mechanics, by emphasising remainder of the book. development, will inevitably bo driven to modern applied aspects. The material is very voyage out into our solar system. He concise and to the point. Note that this could The author then moves on to the central discusses the prospects for terraforming cause some problems tofreshmen. Ho we ver focus of the book: the unmanned robotic Venus, Mars, and a few of the Jovian and if we ever want to excite students about exploration of the planets. He first briefly Saturnian moons. quantum mechanics, we should show them discusses the extent to which life on Earth how useful it really is: this book does that in is detectable from space at various Finally, the author discusses SETI: the an excellent w ay. resolutions and wavelengths. He then search for extraterrestrial intelligence. In describes in more detail various missions the past 35 years this has gradually Quantum Mechanics ... is divided into 9 by the United States and the former Soviet become a serious branch of astronomy, chapters. Folio wing the introductory chapter Union to the Venus, Mars, Jupiter, Saturn, and a growing number of increasingly which introduces the concept of waves and Uranus, and Neptune systems. The author sensitive searches have been made. The particles and discusses modern does an excellent job of conveying the author describes some of major radio SETI nanostructure experiments, the next seven excitement of scientific discovery here, searches to date, and the prospects for chapters guide the reader through describing several cases of conflicting much more sensitive and hopefully Schroedingerequation, tunnel ling, harmonic results and interpretations of ambiguous better-funded ones in the future. He oscilla tor, opera tors, perturbât iont heory and data. I particularly enjoyed his discussion outlines some of the arguments regarding motion in centrally symmetric potentials. of the conflicting evidence for whether the Fermi paradox (if they're out there, The last and more advanced chapter deals Saturn's m oon Titan may have why haven't we seen them yet?), and with electrons and anti-symmetry. hydrocarbon lakes or oceans. closes with some speculations on a distant future when humans voyage to the stars. Quantum Mechanics ... can be used as a The author argues strongly that textbook for teaching QM since every astronomy, by its very nature, tends to Overall, I enjoyed this book. I found the chapter is supplemented with several foster international cooperation: author's wide-ranging discussions problems. I strongly recommend this as researchers "... discover that splendid fascinating, inspiring, and supplementary reading to students work, work that complements their own, is thought-provoking. The many color studying QM, but not as a first textbook. being done by researchers in other nations; photographs and paintings nicely Students studying it will find a very useful or that to solve a problem, you need data complement the text, and are beautifully material that illustrates important aspects or a perspective (access to the southern reproduced. The book deserves a wide of modern solid-state electronics and sky, for example) that is unavailable in readership. quantum mechanics. These topics are your country.". He describes several becoming more and more important in examples of important global effects on Jonathan Thornburg today's microelectronic and optoelectronic Earth that were first discovered by thornbur@t heory. phy sics, ubc.ca devices, not to mention the new emerging planetary astronomers, notably the danger Physics Department, UBC field of nanoelectronics. of nuclear winter and the depletion of In conclusion, this book will be a valuable the ozone layer by addition not only as a teaching source for chlorofluorocarbons. ® C.A.P. 1996. All rights reserved. quantum mechanics but also as a source of information on the principles of modern Authorization to photocopy items for internal or nanoelectronic devices for research physicists. Like most personal use, or the internal or personal use of astronomers, the specific clients, is granted by the C.A.P. Dr. Marék Wartak author is very Department of Physics and Computing skeptical of manned The above permission does not extend to other kinds Wilfrid Laurier University space programs. He of copying, such as copying for general distribution, discusses the Apollo for advertising, or promotional purposes, for creating PALE BLUE DOT: A VISION OF THE program's minimal HUMAN FUTURE IN SPACE, by Carl emphasis on new collective works, or for resale. For such Sagan, Random House, New York, 1994, science, and copying, arrangements must be made with the pp xviii + 429 ISBN 0-679-43841-6 ponders at some publisher. (hardcover) length whether future manned Reprint Price list (B&W) Carl Sagan is a well-known planetary missions to Mars 8 1/2 x 11 Corner Stapled - (GST extra) astronomer and science popularizer, the are a justifiable latter most notably for his "Cosmos" expenditure in the television series. In this book he discusses late 20th and early Add'l a wide range of topics related to the 21st centuries. The Copies 2 pages 4 pages 6 pages 2 pages general theme of planetary astronomy and author then turns to 50 $ 35.00 $ 45.00 $ 55.00 $ 10.00 the exploration of the solar system, at a a consideration of 100 $ 45.00 $ 60.00 $ 75.00 $ 17.50 level similar to "Cosmos", i.e. suitable for the consequences the "interested lay reader". Like his other and likelihood of 200 $ 65.00 $ 90.00 $115.00 $ 30.00 works, this book blends science, history, catastrophic comet 300 $ 95.00 $135.00 $175.00 $ 47.50 speculations on the future, and the or asteroid impacts

La Physique au Canada mars à avril 1996 129 POSTDOCTORAL POSITION

INDUSTRIAL RESEARCH FELLOWSHIPS FABRICATION OF THIN FILMS FOR OPTOELECTRONIC APPLICATIONS MPB Technologies Inc. is seeking candidates to nominate tor Natural Science and Engineering Research Council of Canada Industrial Research Fellowships. Applications are invited for a post-docloral position in the Department of Engineering Plivsics al McMaster The Fellowships will normally be tenable in the Laboratories of MPB Technologies Inc. located at Dorval. Quebec or Ottawa. University. The successful candidate will join a research Ontario. group working on an NSERC Strategic Project on the Projects in which successful candidates may be involved include: fabrication of thin film optical coatings for • Electromagnetics and Millimeter Waves optoelectronic applications. Applicants should hold a • Lasers and Laser Applications • Electro-optics and Acousto-optics Ph D. in Engineering Physics. Physics, or a related • Plasma, Fusion and Space Technology discipline. Experience in plasma assisted C V D and/or • Expert Systems and Artificial Intelligence • Robotics thin film characterization techniques would be an asset. The position is available immediately. Salaries and other benefits are the same as for permanent staff of equivalent experience. Applications, including a cover letter. C V . list of publications, and the names and addresses of at least Interested recent graduates, individuals currently completing postdoctorate fellowships, or candidates who will graduate in Ihe three references should be sent to: near future with a background in physics, electrical engineering or computer science and who are Canadian citizens or landed immigrants are invited to write or call: Dr. Peter Mascher

Dr. M.P. Bachynski Department of Engineering Physics MPB Technologies Inc. McMaster University. Hamilton, Ontario 1725 North Service Road Trans-Canada Hiohway Canada L8S 4L7 Dorval, Quebec CANADA H9P 1J1 Telephone: (514) 683-1490 Fax: (514) 683-1727 Fax: (905) 527-8409 e-mail: [email protected]

GRADUATE RESEARCH ASSISTANTSHIPS The University ATMOSPHERIC AND OCEANIC SCIENCES off British Columbia McGILL UNIVERSITY Graduate Studies in Chemistry Following the graduation last year of nine Ph.D. students in atmospheric and oceanic sciences, a number of research assistant positions are available for highly motivated Ph.D. and QUALITY SCIENCE IN M.Sc. students for the 1996-97 academic year. The current fields of research activity in the Department of Atmospheric and QUALITY ENVIRONMENT Oceanic Sciences include atmospheric physics and chemistry, synoptic and dynamic meteorology, air-sea and air-ice-sea MSc and PhD degree programs in analytical, interactions, coupled atmosphere-oceari modelling, biological, inorganic, organic, physical, nuclear and paleoclimate modelling, climate variability, ocean circulation theoretical chemistry and coastal oceanography. interested students with backgrounds in other disciplines, physics or biology, are also encouraged In addition to the facilities within the Department of to apply Atmospheric and Oceanic Sciences, students can work in radar modern laboratory space and equipment in new meteorology at the J. Stewart Marshall Obsen/atory, interact chemistry/physics and materials science research with members in the Centre for Climate and Global Change buildings Research, and also conduct research with staff at the participation in Networks of Excellence programs in Numerical Weather Prediction Centre in Dorval. There are also protein engineering and mechanical wood pulping opportunities to work with marine scientists at l'Université Laval faculty members with joint appointments in and the Department of Fisheries and Oceans. biochemistry, pharmaceutical sciences, pathology, TRIUMF and oceanography Potential graduate students should have a strong competitive graduate stipends and supplements to undergraduate background in physics, applied mathematics, NSERC and other major scholarship holders engineering, geophysics, computer science, or physical an opportunity to live in Vancouver, a vibrant chemistry. Recent M.Sc. graduates in atmospheric science or international city with a beautiful ocean and mountain physical oceanography are also welcome to apply for Ph.D. setting studies. For further information, please contact the Graduate Forfurther information please write: Studies Coordinator, Department of Atmospheric and Oceanic Dr. P Kash, Professor Phone (604) H22-9206 Sciences, McGill University, 805 Sherbrooke Street West, Department of Chemistry, U.B.C.. Fax (604) 822-2847 Montreal Quebec, H3A 2K6, Canada, or send an e-mail to: Vancouver, B.C.. Canada V6T 1Z1 [email protected] [email protected]. Check out our site on the World Wide Web: http://www.science.ubc.ca/departments/chem Information regarding the department can be seen on our web site: http://zephyr.meteo.mcgill.ca

130 Physics in Canada March/April 1996 Corporate Members // Membres corporatifs Canadian Association of Physicists // Association canadienne des physiciens et physiciennes

The Corporate Members of the Canadian Association of Les membres corporatifs de l'Association canadienne des Physicists are a group of corporations, laboratories, and physiciens et physiciennes sont un groupe de institutions who, through their membership, support the corporations, de laboratoires ou d'institutions qui educational activities of the Association. supportent financièrement les activités éducatives de l'Association. The entire proceeds of corporate membership Les revenus de leurs contributions déductibles aux fins contributions are paid into the CAP Educational Trust d'impôt sont entièrement versés au Fonds Educatif de Fund and are tax deductible. l'ACP.

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The Canadian Association of Physicists cordially invites L'Association canadienne des physiciens et physiciennes interested corporations and institutions to make invite cordialement corporations et institutions à faire application for Corporate membership and will welcome partie des membres corporatifs. Renseignements auprès the inquiries addressed to the Executive Director. de la directrice exécutive.

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