page 3). The RFQ has superseded linear collider ideas aired in reports of the annular coupled structure, a the large high-voltage systems pre­ from SLAC (Stanford), CERN, KEK new coupled-cell configuration. viously necessary in ion accelerator (Japan), and Novosibirsk. Prototyping and construction of injection systems and makes com­ The larger, more exotic and some parts of the JHP linac is un­ pact linacs possible, even for a more expensive these machines derway at KEK. space-based system. Exhibited at become, the more the engineering Linac technology has taken root the conference was the 1 MeV must depart from cut-and-try to ac­ in several fields outside of the par­ RFQ successfully tested aboard a curate design. Thus another tech­ ticle physics laboratories. One new rocket in a Los Alamos defence nological advance is in computer community with more than 16 pro­ technology project. design codes. The newer codes jects represented at Linac90 and Among many other advanced can handle r.f. cavities, beam op­ surveyed by C. Pellegrini (UCLA) is RFQ projects heard at Linac90 tics elements, and beam dynamics developing the free electron laser, were the 250 mA unit at CERN re­ with greater accuracy. This has requiring a high intensity electron li­ ported by M. Weiss; the 100% been important for RFQ and super­ nac. One example, reported by P. duty-factor 75 mA RFQ at Chalk conducting cavity development, O'Shea (Los Alamos), will run 300 River, reported by G. McMichael; and design of any high perfor­ A at 40 MeV. and a variable-energy RFQ for hea­ mance machine. R. Cooper (Los Al­ In possible futuristic applica­ vy ions described by A. Schempp amos) reported on the new and tions, for example the accelerator from Frankfurt. An innovative specialized field of accelerator de­ transmutation of radioactive waste feature which J. Watson said will sign codes, which recently had its or tritium production schemes be tried in front of the RFQ for the second conference. sketched by G. Lawrence (Los Ala­ proposed US Superconducting Su­ Several papers, such as J. mos), a high premium is placed on percollider (SSC) is a helical quadru- Warner's from CERN or Y. Yama- linac power efficiency. I. Hofmann pole. At Argonne, work is under­ zaki's from KEK, indicated that new from GSI (Darmstadt) and R. Ban- way towards a superconducting linac structures could be on the gerter from Berkeley, among oth­ RFQ. way. Since a big advance may be ers, reported on current develop­ Large future accelerator projects necessary for TeV linear colliders, ment of r.f. and induction linacs to will also lean towards supercon­ people at some major Laboratories drive fusion reactors. In his sum­ ducting radiofrequency cavities as are thinking about entirely new mi­ mary P. Grand (Brookhaven) specu­ a design option. The largest scale crowave structures. Linear collider lated whether civilization's need foi application to date is the ATLAS projects at CERN (CLIC - Novem­ energy might eventually become heavy-ion machine at Argonne, ber, page 5) and in Japan (JLC) are the prime force for development of described by K. Shepard, but of looking in this direction, as re­ linac technology. course the real showpiece will be ported by G. Guignard and H. Mat- The main organizers of Linac90 the CEBAF machine with recirculat­ sumoto respectively, with the latter were Stan Schriber and Bob Harde- ing linacs now being built at New­ having achieved accelerating gra­ kopf from Los Alamos. port News, Virginia, where cavities dients of 85 MV/m in a 0.6 m have achieved high fields (Septem­ tank. T. Weiland reported that From Olin van Dyck ber/October, page 43). Summariz­ DESY and Darmstadt are thinking ing the field, H. Padamsee (Cornell) about a 500 GeV (total) electron- reported that about 70 metres of positron linear collider using refine­ superconducting cavities have been ments of existing technology. ORSAY built so far at various institutions, Apparently closer to realization either for development or real use is the Japanese Hadron Project, the Tau workshop (November, page 20). subject of several reports at the From 24-27 September 120 physi­ To reach accelerating gradients conference. The linac stage of this cists met at the French Orsay Lab­ ten times higher may require some machine will deliver a 1 GeV beam; oratory for a meeting devoted to other technological development among the advanced design the tau lepton and its associated such as r.f. pulse compression (No­ features will probably be perma­ neutrino. vember, page 5). New ideas such nent magnet quadrupoles in the The tau was discovered in 1975 as this play a key role in the 1 TeV drift-tube section and possibly use by Martin Perl and his collaborators

22 CERN Courier, December 1990 Tau lepton pioneer Martin Perl (centre) at the recent tau physics workshop at the French Or say Laboratory, flanked by workshop organizers Michel Davier (Orsay Director, right) and Bernard Jean-Marie.

their Z profiles from tau pairs and their forward-backward production asymmetries, all measurements in accord with the Standard Model. Aleph and Delphi have looked at tau polarization, with Aleph data suggesting parity violation in both tau production and decay. To­ gether, the L£P results test the 'universality' (family independence) of lepton coupling to the neutral current with ten times better preci­ sion than before. For the future, the Beijing BEPC ring should provide a better meas­ urement of the tau mass, but LEP and lower energy machines should provide the bulk of new tau data. working with the Mark I detector at collaboration at DESY succeeds in High luminosity electron-positron the SPEAR electron-positron ring at arriving at a coherent description rings are being proposed to pro­ Stanford. This unexpected discove­ without any problems, and a pre­ vide bulk data in relatively un- ry heralded a scenario of three fam­ liminary appraisal by the Aleph ex­ probed corners. B-factories geared ilies of leptons and quarks, sub­ periment at LEP, looking at the de­ to look at CP violation are not op­ sequently confirmed by the discov­ cays of Z particles into tau pairs timized for tau physics, although ery of the fifth kind of quark at Fer- and exploiting the detector's pho­ they should open up some new milab in 1977. ton reconstruction and identifica­ reaction channels. A tau-charm fac­ The existence of a third family tion capabilities, confirms these re­ tory would be better adapted for allows the violation of CP symme­ sults. Continuation of these studies tau physics and a design is on the try to be accommodated in (but not and new information from the Cleo drawing board at CERN (but not ne­ explained by) the Standard Model. II detector at Cornell's CESR ring cessarily for construction on the While the sixth ('top') quark has should tidy up the tau decay pic­ CERN site). yet to show itself, experiments at ture. The final topic at the workshop high energy electron-positron col­ In this area, two results were was the tau neutrino. Mass liders have shown that there is presented by the Argus experiment measurements of this elusive parti­ room in Nature for only three at DESY - a high precision meas­ cle are difficult and are attempting quark-lepton families. urement of the Michel parameter to go below the present limit of 35 The Orsay meeting was the first for leptonic tau decays in accord MeV. Tau neutrino interactions are to concentrate exclusively on tau with theory, and the first observa­ difficult to catch, and drive ideas physics, covering from the early tion of parity violation in the decay for new precision detectors. days at SPEAR and at the DORIS of a tau into three pions and a neu­ Overall, the tau is an excellent ring at DESY through to the latest trino, providing another incisive testbed for the Standard Model, results from LEP. probe of the underlying theory. and could be the scene of import­ After an introduction from tau Despite these new results, tau in­ ant new revelations in the coming pioneer Martin Perl, the meeting formation is still meagre compared years. surveyed tau decays, where the with, say, the wealth of data in the The Orsay tau workshop was situation is far from clear. Missing muon sector. organized by Michel Davier, decays could be due to systematic The meeting went on to look at Director of Orsay's Linear Acceler­ experimental underestimations, or the coupling of the tau to the neu­ ator Laboratory, and Bernard to new physics, so clarification is tral current of weak interactions. Jean-Marie. important. The four LEP experiments - Aleph, A global analysis by the Cello Delphi, L3 and Opal - presented From Michel Davier

CERN Courier, December 1990 23 Experimental

high energy psysicists m/f Applications are invited for post­ successful applicants will join one of the doctoral and tenure-track positions in present experimental teams. Particle Physics Research at the section They should demonstrate originality High Energy Physics of the National and initiative in their research activities Institute tor Nuclear Physics and High and possibly help initiating future Energy Physics (NIKHEF) in research directions of the laboraty. Amsterdam. The institute is involved in experiments at CERN (UA1, Delphi and Information L3) and DESY (ZEUS); it also has a Further information can be obtained theory group. from the Scientific Director, prof. dr. In view of the LCH project at CERN K.J.F. Gaemers, telephone R&D projects have started on several xx31.20.5925001. aspects of detector technology. The academic staff, including PhD Applications students, consists of about 60 physicists. Letters of application, including Technical support is provided by well curriculum vitae, list of publications and equipped mechnical and electronic the names of at least three references are workshops. The institute has its own, to be sent within three weeks after up to date, computing facilities. publication of the advertisement to the personnel officer m;. T. van Egdom, Requirements P.O. Box 41882, 1009 DB Amsterdam, Candidates should have a PhD degree, the Netherlands. preferably in Experimental Particle Physics. Applicants may be considered for a tenured position when they have at least several years of post-doctoral experience with a strong record of accomplishment. It is assumed that

Experimental Nuclear European Synchrotron Radiation Facility Physicist Grenoble - France There is a vacancy for a nuclear physicist at our Chalk River Laboratories in a research group that studies nuclei far from stability The Survey & Alignment Group in the Technical Services and weak interactions in nuclei. The group centers its activities about the TASCC accelerator facilities (a coupled Tandem Accelerator is looking for: and Superconducting Cyclotron which produces heavy ion beams from lithium at 50 MeV/u to uranium at 10 MeV/u) and the Chalk A TECHNICIAN (M/F) River on-line isotope separator. The successful candidate will be specialized in Geodesic measurements expected to collaborate in the activities of the existing group and to assume a leadership role in related experimental research. This group has the task of installing, measuring and adjusting all sensitive equipment of the Synchrotron Candidates with several years of relevant post-doctoral research experience will be preferred. In that case, appointment will be to Accelerator. Later, it will be in charge of the positioning of a position that is directly convertible to a permanent one after two all equipment in the large Experimental Hall round the years of satisfactory service. More junior candidates would be beam-lines. considered initially for a Research Associate position. Salary will be commensurate with experience. Qualification & Experience : He/she must have a sound Application forms may be obtained from the Employment Office, basic education (HNC) or equivalent, at least 5 years Chalk River Laboratories, CHALK RIVER, Ontario, Canada, K0J experience in topometrics and micro-geodesy. Good 1 JO and completed forms, curriculum vitae and publication list should knowledge in acceleration & micro-informatics would be be sent, no later than January 15,1991 to Dr. J.C. Hardy, Director of TASCC, at the same address, quoting File No. PPHS-9088. appreciated. Candidates should arrange for three letters of reference to be sent to Dr. Hardy. The working language in ESRF is English : knowledge of French is desirable. This advertisement is directed in the first instance to Canadian citizens or permanent residents, but all qualified candidates are encouraged Please state your name, address and the reference number, to apply. and we shall provide you with an 'Application Form' to be AECL has an active Employment Equity Program and encourages sent back to us before 15 December 1990 to applications from women, aboriginals, visible minorities and persons with disabilities. ESRF Recruitment Office - Ref : 6523 A> AECL EACL BP 220 AECL Research EACL Recherche F - 38043 GRENOBLE CEDEX France

24 CERN Courier, December 1990 People and things

Paul Murphy recently retired as head of the particle physics group at Manchester.

On people Laboratory correspondents Maury Tigner of Cornell is one of the six recipients of this year's E.O. Argonne National Laboratory, USA M. Derrick Lawrence Awards in the US for his Brookhaven National Laboratory, USA contributions to high energy accel­ A. Stevens erator technology, including design CEBAF Laboratory, USA for Cornell's CESR Electron Storage S. Corneliussen Ring, the development of super­ CERN, Geneva conducting radiofrequency cavities G. Fraser and his direction of the conceptual Cornell University, USA design of the planned US Super­ D. G. Cassel conducting Supercollider (SSC). DESY Laboratory, Fed. Rep. of Germany P. Waloschek Fermi National Accelerator Laboratory, Walter E. Massey of Chicago, USA former Director of the Argonne M. Bodnarczuk Roger Rlin-Stoyie, Honorary Profes­ Laboratory becomes Director of the sor of Theoretical Physics at Sus­ GSI Darmstadt, Fed. Rep. of Germany US National Science Foundation, G. Siegert sex, becomes President of the UK succeeding Erich Bloch. Massey Institute of Physics for 1990-92. INFN, Italy leaves his position as Vice-Presi­ A. Pascolini dent of the American Physical So­ IHEP, Beijing, China Herbert Lengeler of CERN's Accel­ Qi IMading ciety, where Ernest M. Henley now erator Technology Division, and a becomes President-Elect. JINR Dubna, USSR member of the CERN Courier Advi­ B. Starchenko sory Panel, been nominated Hono­ KEK National Laboratory, Japan Peter Higgs of Edinburgh receives rary Professor of Physics at the S. Iwata the 1990 Scottish Science Award Technische Hochschule, Darm­ Lawrence Berkeley Laboratory, USA for his work in theoretical physics, B. Feinberg stadt, Germany. particularly in the unification of fun­ y Los Alamos National Laboratory, USA O. B. van Dyck damental forces. This Award was attributed for the first time in Paul Murphy retires NIKHEF Laboratory, Netherlands F. Erne 1989. Novosibirsk Institute, USSR Paul Murphy retired recently as V, Balakin Michael Riordan, Science Informa­ head of the particle physics group Orsay Laboratory, France tion Officer at the Stanford Linear at Manchester. Involved in many Anne-Marie Lutz Accelerator Center (SLAC) and au­ early experiments at then new ac­ PSI Laboratory, Switzerland thor of the book 'The Hunting of J. F. Crawford celerators - the Liverpool 400 MeV the Quark', moves to Washington synchrocyclotron, the Bevatron at Rutherford Appleton Laboratory, UK Jacky Hutchinson to become Assistant to John S. Berkeley and the UK Nimrod proton Toll, President of the Universities' Saclay Laboratory, France synchrotron, he became Professor Elisabeth Locci Research Association, the govern­ of Experimental Physics at Man­ IHEP, Serpukhov, USSR ing body of both Fermilab and the chester in 1965 and moved his at­ Yu. Ryabov planned US Superconducting Su­ tention to another new machine, Stanford Linear Accelerator Center, USA percollider (SSC). Michael is also the NINA electron synchrotron at M. Riordan SLAC's CERN Courier corre­ nearby Da res bury. He has turned Superconducting Super Coilider, USA spondent. his attention in more recent years N. V. Baggett to experiments at colliders - first TRIUMF Laboratory, Canada M. K. Craddock Mark Sakitt becomes Assistant Di­ the ISR at CERN, then with the rector of Planning and Policy at JADE experiment at the PETRA Brookhaven. ring at DESY, and most recently

CERN Courier, December 1990 25