DOCSLIB.ORG

Peaceful Uses of Fusion

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Peaceful Uses of Fusion P/2410 USA Peaceful Uses of Fusion By Edward Teller * INTRODUCTORY REMARKS ticles involved in that explosion will necessarily move It is a great pleasure to discuss with you the topic with high velocity. of the day and I should like to begin by expressing The second and more important difference is the the same sentiments with which the previous speaker following: The fission chain reaction is regulated finished his paper. It is wonderful that over a large by assembling the correct amounts of active materials and important area of research we can now all talk and absorbers. If the correct amount is exceeded, and work together freely. I hope that this spirit the energy release rises in a rather slow manner due of cooperation will endure, that it will be generally to the action of delayed neutrons. In contrast, the exercised throughout the world in this field and that main regulating feature in a fusion reaction is the it will be extended also to other fields. temperature. When a certain ignition temperature has been exceeded, the reaction itself raises the It is remarkable how closely parallel the develop- temperature and this leads to an exceedingly rapid ments in the different countries are and this, of course, acceleration of further energy release. Slow energy is due to the fact that we all live in the same world release is possible only at low densities ; but this raises and obey the same laws of nature. I was particularly further problems. impressed by the wealth of detail given by the previous speaker. I should like to tell you a few generalities and, perhaps, a few little details which might help you HISTORY or might amuse you. Additional details can, of course, be found in other papers submitted to this The problem of controlled fusion is difficult but not conference. necessarily insoluble. Some of us discussed it in a rather detailed manner during the war in Los Alamos. FUSION AND FISSION This group included Enrico Fermi, John von Neumann, James Tuck and Luis Alvarez. The problem of how to release fusion energy in an explosion process was solved several years ago. Some elementary general facts were recognized at How to release this energy in a slow and controlled that time : That deuterium gas could react t above manner has proved to be a much harder question. an ignition point of approximately 35 kilovolts; that This situation is in sharp contrast with the history of deuterium-tritium mixtures could react î at a con- energy release from fission. One year of intensive siderably lower temperature of a few kilovolts; that the gas should be introduced at an exceedingly low work had sufficed to produce the first nuclear reactor 14 15 3 in the early winter of 1942, while several more years density of approximately 10 to 10 particles/cm were needed to perform the first successful nuclear in order to make the reaction rates sufficiently slow detonation. and in order to avoid excessively high pressures; that at these high temperatures the gas will be Among the reasons for this difference I should like completely ionized (such an ionized gas is called a to mention two which are simple and important. plasma) ; that with the presence of magnetic fields, the Fission energy is released by the mechanism of a ions in this plasma follow spiral paths and that by chain reaction. The chain-carrying neutrons can be appropriate arrangement of the magnetic fields the slowed easily. This facilitates a controlled reaction losses to the walls can be reduced; that the pressure not only because the time that the process takes of the plasma on the field leads to a thermal expansion becomes longer but also because slow neutrons are of the plasma which tends to stabilize the reaction; more easily controlled by specific absorbers and other that equilibrium with radiation is not established and means. On the other hand, release of fusion energy that the energy emitted as bremsstrahlung should be is accomplished by a heat explosion or, to use the treated as a loss ; that for this reason atoms other than technical term, a thermonuclear reaction. The par- t The reactions areD + D->T + H Mev and * University of California Radiation Laboratory, Livermore, D + D -> He3 + n + 3.25 Mev. California. t The reaction is D + T -* He3 + n + 18 Mev. 27 28 SESSION 4 P/2410 E. TELLER hydrogen isotopes must be eliminated as completely Laboratory, at the Los Alamos Scientific Laboratory as possible; and that even the equilibrium between and at the Naval Research Laboratory. electron and positive ion energies will not be complete at the highest temperatures. Very particularly, it was also noticed that in a simple closed field along a torus, A COMPARISON OF THE APPROACHES the particles will not continue to spiral indefinitely around the same magnetic line of force but that they Each of these proposals has its peculiar advan- will drift in a direction perpendicular to both the mag- tages and its peculiar difficulties. The pinch effect netic field and the field gradient. This leads to smaller is based on an earlier idea of Willard Bennett \ who but nevertheless prohibitive wall losses. For the time derived the relations according to which a violent gas being, no experimental work was undertaken for the discharge will contract into a narrow filament under specific purpose of carrying the theoretical considera- the influence of its own magnetic field. The great tions into practice. virtue of this scheme lies in the fact that starting from a rather moderate plasma density one can push In 1952 and 1953, under the stimulus of a successful the system to very much higher densities and pressures man-made release of thermonuclear energy, such an and at the same time expose the containing system experimental approach was started. To a very great to much more moderate pressures. One price that extent this was due to the initiative and confidence one has to pay is that the high densities are obtained of the chairman of the Atomic Energy Commission, only for short periods of time. In other words, we Lewis L. Strauss. It was recognized that the prob- are dealing with a pulsed machine. In order to avoid lems of heating and containing the plasma would be instability and breakup of the pinch, the original extremely difficult. For this reason, several parallel simplicity of the concept had to be compromised by approaches were undertaken which, between them, introducing magnetic fields parallel to the direction amounted to an attack on plasma research on a broad of the plasma current. The detailed theory of the front. pinch contraction, as well as the theory of pinch stabilization, was worked out by M. Rosenbluth at Los Alamos. THE PRESENT APPROACHES Rather early in the game it was noticed that the pinch effect in deuterium gives rise to copious neutron Two of these approaches, the pinch and the stella- emission. The first public announcement of this fact rator, were based on the idea of containing the plasma was made by I. V. Kurchatov.2 Unfortunately, these in an annular region. The main difference between neutrons do not appear to be of thermonuclear origin. these two approaches is that in the pinch an axial Considerable progress has been made by S. A. Colgate current is established with magnetic lines of force in explaining the mechanism by which these neutrons encircling the current, while in the stellarator the roles are produced. A general difficulty in the pinch effect of current and magnetic lines are reversed with the seems to arise from the circumstance that during the principal currents established outside the reacting formation of the high-current filament most of the region. In the United States, the work on the pinch original energy output is lost to the walls. It seems effect was started by James Tuck in Los Alamos. to be of the greatest importance to understand and Later, similar work was undertaken in the University prevent these losses. of California Radiation Laboratory by W. R. Baker The Astron is based on the following observation: and S. A. Colgate and still later at other sites. This In contrast to the instability of the pinch current, it is approach has also been very strongly emphasized by expected that a current of relativistic electrons will be workers in the United Kingdom and in the USSR. stable. If this proves to be correct then one can con- Nicholas С Christofilos proposed an ingenious steady- fine a plasma in the field which encircles this rela- state arrangement, the Astron, which bears some tivistic current for a longer period than in an unstable similarity to the pinch effect. The stellarator was pinch. This arrangement is under development at proposed by Lyman Spitzer at the very beginning of Livermore. the thermonuclear program and work on it was The thorough theoretical studies of the stellarator, carried out in Princeton. carried out by L. Spitzer, M. Kruskal, E. Frieman Taking an entirely different approach, the advan- and others, led to the recognition that the simplest tages of a confinement geometry based on externally arrangements of magnetic lines are unstable in this generated, cylindrically symmetric magnetic fields case also. In order to prevent these instabilities, were recognized by Richard Post and Herbert York. additional magnetic fields are being introduced in a Starting with these concepts, Post evolved an approach direction perpendicular to the original fields. Thus which has come to be called the " Mirror Machine ", the present pinch and stellarator designs are no longer which uses various applications of the magnetic as sharply different as they used to be.
Load more

Recommended publications
  • Richard G. Hewlett and Jack M. Holl. Atoms
    ATOMS PEACE WAR Eisenhower and the Atomic Energy Commission Richard G. Hewlett and lack M. Roll With a Foreword by Richard S. Kirkendall and an Essay on Sources by Roger M. Anders University of California Press Berkeley Los Angeles London Published 1989 by the University of California Press Berkeley and Los Angeles, California University of California Press, Ltd. London, England Prepared by the Atomic Energy Commission; work made for hire. Library of Congress Cataloging-in-Publication Data Hewlett, Richard G. Atoms for peace and war, 1953-1961. (California studies in the history of science) Bibliography: p. Includes index. 1. Nuclear energy—United States—History. 2. U.S. Atomic Energy Commission—History. 3. Eisenhower, Dwight D. (Dwight David), 1890-1969. 4. United States—Politics and government-1953-1961. I. Holl, Jack M. II. Title. III. Series. QC792. 7. H48 1989 333.79'24'0973 88-29578 ISBN 0-520-06018-0 (alk. paper) Printed in the United States of America 1 2 3 4 5 6 7 8 9 CONTENTS List of Illustrations vii List of Figures and Tables ix Foreword by Richard S. Kirkendall xi Preface xix Acknowledgements xxvii 1. A Secret Mission 1 2. The Eisenhower Imprint 17 3. The President and the Bomb 34 4. The Oppenheimer Case 73 5. The Political Arena 113 6. Nuclear Weapons: A New Reality 144 7. Nuclear Power for the Marketplace 183 8. Atoms for Peace: Building American Policy 209 9. Pursuit of the Peaceful Atom 238 10. The Seeds of Anxiety 271 11. Safeguards, EURATOM, and the International Agency 305 12.
    [Show full text]
  • Ira Sprague Bowen Papers, 1940-1973
    http://oac.cdlib.org/findaid/ark:/13030/tf2p300278 No online items Inventory of the Ira Sprague Bowen Papers, 1940-1973 Processed by Ronald S. Brashear; machine-readable finding aid created by Gabriela A. Montoya Manuscripts Department The Huntington Library 1151 Oxford Road San Marino, California 91108 Phone: (626) 405-2203 Fax: (626) 449-5720 Email: [email protected] URL: http://www.huntington.org/huntingtonlibrary.aspx?id=554 © 1998 The Huntington Library. All rights reserved. Observatories of the Carnegie Institution of Washington Collection Inventory of the Ira Sprague 1 Bowen Papers, 1940-1973 Observatories of the Carnegie Institution of Washington Collection Inventory of the Ira Sprague Bowen Paper, 1940-1973 The Huntington Library San Marino, California Contact Information Manuscripts Department The Huntington Library 1151 Oxford Road San Marino, California 91108 Phone: (626) 405-2203 Fax: (626) 449-5720 Email: [email protected] URL: http://www.huntington.org/huntingtonlibrary.aspx?id=554 Processed by: Ronald S. Brashear Encoded by: Gabriela A. Montoya © 1998 The Huntington Library. All rights reserved. Descriptive Summary Title: Ira Sprague Bowen Papers, Date (inclusive): 1940-1973 Creator: Bowen, Ira Sprague Extent: Approximately 29,000 pieces in 88 boxes Repository: The Huntington Library San Marino, California 91108 Language: English. Provenance Placed on permanent deposit in the Huntington Library by the Observatories of the Carnegie Institution of Washington Collection. This was done in 1989 as part of a letter of agreement (dated November 5, 1987) between the Huntington and the Carnegie Observatories. The papers have yet to be officially accessioned. Cataloging of the papers was completed in 1989 prior to their transfer to the Huntington.
    [Show full text]
  • Inis: Terminology Charts
    IAEA-INIS-13A(Rev.0) XA0400071 INIS: TERMINOLOGY CHARTS agree INTERNATIONAL ATOMIC ENERGY AGENCY, VIENNA, AUGUST 1970 INISs TERMINOLOGY CHARTS TABLE OF CONTENTS FOREWORD ... ......... *.* 1 PREFACE 2 INTRODUCTION ... .... *a ... oo 3 LIST OF SUBJECT FIELDS REPRESENTED BY THE CHARTS ........ 5 GENERAL DESCRIPTOR INDEX ................ 9*999.9o.ooo .... 7 FOREWORD This document is one in a series of publications known as the INIS Reference Series. It is to be used in conjunction with the indexing manual 1) and the thesaurus 2) for the preparation of INIS input by national and regional centrea. The thesaurus and terminology charts in their first edition (Rev.0) were produced as the result of an agreement between the International Atomic Energy Agency (IAEA) and the European Atomic Energy Community (Euratom). Except for minor changesq the terminology and the interrela- tionships btween rms are those of the December 1969 edition of the Euratom Thesaurus 3) In all matters of subject indexing and ontrol, the IAEA followed the recommendations of Euratom for these charts. Credit and responsibility for the present version of these charts must go to Euratom. Suggestions for improvement from all interested parties. particularly those that are contributing to or utilizing the INIS magnetic-tape services are welcomed. These should be addressed to: The Thesaurus Speoialist/INIS Section Division of Scientific and Tohnioal Information International Atomic Energy Agency P.O. Box 590 A-1011 Vienna, Austria International Atomic Energy Agency Division of Sientific and Technical Information INIS Section June 1970 1) IAEA-INIS-12 (INIS: Manual for Indexing) 2) IAEA-INIS-13 (INIS: Thesaurus) 3) EURATOM Thesaurusq, Euratom Nuclear Documentation System.
    [Show full text]
  • The Stellarator Program J. L, Johnson, Plasma Physics Laboratory, Princeton University, Princeton, New Jersey
    The Stellarator Program J. L, Johnson, Plasma Physics Laboratory, Princeton University, Princeton, New Jersey, U.S.A. (On loan from Westlnghouse Research and Development Center) G. Grieger, Max Planck Institut fur Plasmaphyslk, Garching bel Mun<:hen, West Germany D. J. Lees, U.K.A.E.A. Culham Laboratory, Abingdon, Oxfordshire, England M. S. Rablnovich, P. N. Lebedev Physics Institute, U.S.3.R. Academy of Sciences, Moscow, U.S.S.R. J. L. Shohet, Torsatron-Stellarator Laboratory, University of Wisconsin, Madison, Wisconsin, U.S.A. and X. Uo, Plasma Physics Laboratory Kyoto University, Gokasho, Uj', Japan Abstract The woHlwide development of stellnrator research is reviewed briefly and informally. I OISCLAIWCH _— . vi'Tli^liW r.'r -?- A stellarator is a closed steady-state toroidal device for cer.flning a hot plasma In a magnetic field where the rotational transform Is produced externally, from torsion or colls outside the plasma. This concept was one of the first approaches proposed for obtaining a controlled thsrtnonuclear device. It was suggested and developed at Princeton in the 1950*s. Worldwide efforts were undertaken in the 1960's. The United States stellarator commitment became very small In the 19/0's, but recent progress, especially at Carchlng ;ind Kyoto, loeethar with «ome new insights for attacking hotii theoretics] Issues and engineering concerns have led to a renewed optimism and interest a:; we enter the lQRO's. The stellarator concept was borr In 1951. Legend has it that Lyman Spiczer, Professor of Astronomy at Princeton, read reports of a successful demonstration of controlled thermonuclear fusion by R.
    [Show full text]
  • Highlights in Early Stellarator Research at Princeton
    J. Plasma Fusion Res. SERIES, Vol.1 (1998) 3-8 Highlights in Early Stellarator Research at Princeton STIX Thomas H. Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08540, USA (Received: 30 September 1997/Accepted: 22 October 1997) Abstract This paper presents an overview of the work on Stellarators in Princeton during the first fifteen years. Particular emphasis is given to the pioneering contributions of the late Lyman Spitzer, Jr. The concepts discussed will include equilibrium, stability, ohmic and radiofrequency plasma heating, plasma purity, and the problems associated with creating a full-scale fusion power plant. Brief descriptions are given of the early Princeton Stellarators: Model A, Model B, Model B-2, Model B-3, Models 8-64 and 8-65, and Model C, and also of the postulated fusion power plant, Model D. Keywords: Spitzer, Kruskal, stellarator, rotational transform, Bohm diffusion, ohmic heating, magnetic pumping, ion cyclotron resonance heating (ICRH), magnetic island, tokamak On March 31 of this year, at the age of 82, Lyman stellarator was brought to the headquarters of the U.S. Spitzer, Jr., a true pioneer in the fields of astrophysics Atomic Energy Commission in Washington where it re- and plasma physics, died. I wish to dedicate this presen- ceived a favorable reception. Spitzer chose the name tation to his memory. "Project Matterhorn" for the project which was to be Forty-six years ago, in early 1951, Spitzer, then sited in the Princeton area, on the newly acquired For- chair of the Department of Astronomy at Princeton restal tract, and funding began on July 1 of that year University, together with Princeton physicist John 121- Wheeler, had been thinking about the physics of ther- Spitzer's earliest stellarator papers comprise a truly monoclear processes.
    [Show full text]
  • Tomographic Inversion of Wendelstein 7-X Stellarator Plasmas
    45th EPS Conference on Plasma Physics P4.1056 Tomographic inversion of Wendelstein 7-X stellarator plasmas C. Brandt1, H. Thomsen1, T. Andreeva, N. Lauf1, U. Neuner1, K. Rahbarnia1, J. Schilling1, T. Broszat1, R. Laube1 and the Wendelstein 7-X Team 1 Max-Planck-Institute for Plasma Physics, Greifswald, Germany In the operational phase OP1.2a (Aug-Dec 2017) of the Wendelstein 7-X (W7-X) stellarator experiment the soft X-ray tomography diagnostic (XMCTS: soft X-ray multi camera tomogra- phy system) has been commissioned. Soft X-ray tomography systems are powerful diagnostics for high temperature plasmas measuring spatiotemporal X-ray emissivity profiles. The XMCTS consists of 20 poloidally arranged pinhole cameras at one toroidal location observing a triangu- lar shaped up-down symmetric plasma cross section. X-ray radiation is mainly emitted in the hot plasma core (electron temperatures > 1keV). In the pinhole cameras the plasma radiation is filtered by a beryllium foil of 12:5 mm thickness being transmissible for X-ray radiation above 1keV. Taking into account the detector silicon thickness of 100 mm the detectable energy range is limited to approximately 1 − 10keV. With 18 available cameras in OP1.2a the soft X-ray emissivity has been recorded along 324 lines-of-sight with a time resolution of 0:5 ms. The presentation concentrates on the preparation and first results of the tomographic inver- sion. For correct calculation of the tomograms, both, the knowledge of the exact geometry of the lines-of-sight and the sensitivity of each photodiode are of crucial importance. The as-built coordinates of the cameras have been measured after the in-vessel installation.
    [Show full text]
  • Clean..Up Drive Enlists Support of Many Groups
    .,' - ..'",", -;. --::' ' - ---. ~ 'I '--:-r'~';--'--'~- .,'_.' All the News of All the Point,. , Every Thur,d.y Morning * * • rosse ews C.II TUx.d~2.6900 Complete News Coverage of All the Pointes VOLUME 2o--No. 17 llc Per Cop,. Entered .. Second ClaN Matter '3.50 Per Year at the POit OUlce •• Detroit, Mich. GROSSE POINTE. MICHIGAN,' APRIL 23, 1959 24 PAGES - TWO SECTIONS Section I HEADLINES ,Architect's Drawi ng Shows Church Expo nsion Presbyterians of th,. Clean ..Up Drive ,WEEK LalIDch Big' As Compiled by tb, Enlists Support of Fund Drive Gross, Point, Ne'ws Would Extend Na.ve and Thursday, April 16 Many Groups Construct Hall; May PRESIDENT EISENHOWER, Erect Tower and lad and moist-eyed, announced Get Organ the resignation of Secretary of Garden Club Council Assisted by Hi-Y Clubs, Girl State John Foster Dulles. The Scouts. Merchants and Private Groups; A $600,000 builcling pro. Chief Executive said he has not picked a successor to Dul- Drive Starts May I grtlm has' been. announced les, but promised to fill the . for the G r 0 ss ePointe post as "quickly as practi- The hot summer days of this past week~ have Woods Pre s by t e ria n cable." Reports indicate that brought out swarms of home owners, armed with rakes, Church, 199,50 Mack ave" Under Secretary of S tat e spades and baskets, for the' preliminary "tidying" of nue. The needs invol/e an Christian Hertel', 64, is the lawns and gardens. Judging from this activity, many extension of' the church likeliest choice. residents will not need the door-hanger reminders of nave to add to the seating Dulles' was fOl'ced to resign C1eal.l-Up which will be distributed by the Boy Scouts capacity.
    [Show full text]
  • On Fusion Driven Systems (FDS) for Transmutation
    R-08-126 On fusion driven systems (FDS) for transmutation O Ågren Uppsala University, Ångström laboratory, division of electricity V E Moiseenko Institute of Plasma Physics, National Science Center Kharkov Institute of Physics and Technology K Noack Forschungszentrum Dresden-Rossendorf October 2008 Svensk Kärnbränslehantering AB Swedish Nuclear Fuel and Waste Management Co Box 250, SE-101 24 Stockholm Tel +46 8 459 84 00 CM Gruppen AB, Bromma, 2008 ISSN 1402-3091 Tänd ett lager: SKB Rapport R-08-126 P, R eller TR. On fusion driven systems (FDS) for transmutation O Ågren Uppsala University, Ångström laboratory, division of electricity V E Moiseenko Institute of Plasma Physics, National Science Center Kharkov Institute of Physics and Technology K Noack Forschungszentrum Dresden-Rossendorf October 2008 This report concerns a study which was conducted for SKB. The conclusions and viewpoints presented in the report are those of the authors and do not necessarily coincide with those of the client. A pdf version of this document can be downloaded from www.skb.se. Summary This SKB report gives a brief description of ongoing activities on fusion driven systems (FDS) for transmutation of the long-lived radioactive isotopes in the spent nuclear waste from fission reactors. Driven subcritical systems appears to be the only option for efficient minor actinide burning. Driven systems offer a possibility to increase reactor safety margins. A comparatively simple fusion device could be sufficient for a fusion-fission machine, and transmutation may become the first industrial application of fusion. Some alternative schemes to create strong fusion neutron fluxes are presented. 3 Sammanfattning Denna rapport för SKB ger en övergripande beskrivning av pågående aktiviteter kring fusionsdrivna system (FDS) för transmutation av långlivade radioaktiva isotoper i kärnavfallet från fissionskraftverk.
    [Show full text]
  • Lyman Spitzer 1914–1997
    OBITUARIES ried out sonar analysis at Columbia University Lyman Spitzer as a guide to anti-submarine tactics. After the Deaths of Fellows 1914–1997 war, he went back briefly to Yale and in 1947 he was invited to succeed Russell as Professor of Prof. J Wdowczyk yman Spitzer died on 31 March 1997 at Astronomy at Princeton. He accepted, and held Born 28 July 1935 the age of 82. He had a remarkably pro- the post until his formal retirement in 1982. Elected 11 April 1980 Lductive career that spanned quite diverse At Princeton he developed his theories of the Died 6 September 1996 areas of activity and led him to become one of interstellar medium, and the application of his Dr C P Gopalaraman the most influential American scientists of his great knowledge and understanding of physics Born 1 July 1938 time. His personal theoretical contributions to raised the subject to an exciting level. He Elected 13 May 1994 interstellar astronomy and to plasma physics quickly realized that observations of the inter- Died 3 September 1997 quickly established him as a world leader in each stellar gas were most important in the ultra- Mr S Bradford Downloaded from https://academic.oup.com/astrogeo/article/38/6/36/194930 by guest on 24 September 2021 field. He was a pioneer in the opening up of violet where most of the resonance lines of the Born 28 February 1912 common elements lay. This led to a proposal Elected 14 April 1961 for an ultraviolet observatory satellite designed Died ? specifically to study the interstellar medium.
    [Show full text]
  • Stellarator and Tokamak Plasmas: a Comparison
    Home Search Collections Journals About Contact us My IOPscience Stellarator and tokamak plasmas: a comparison This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2012 Plasma Phys. Control. Fusion 54 124009 (http://iopscience.iop.org/0741-3335/54/12/124009) View the table of contents for this issue, or go to the journal homepage for more Download details: IP Address: 130.183.100.97 The article was downloaded on 22/11/2012 at 08:08 Please note that terms and conditions apply. IOP PUBLISHING PLASMA PHYSICS AND CONTROLLED FUSION Plasma Phys. Control. Fusion 54 (2012) 124009 (12pp) doi:10.1088/0741-3335/54/12/124009 Stellarator and tokamak plasmas: a comparison P Helander, C D Beidler, T M Bird, M Drevlak, Y Feng, R Hatzky, F Jenko, R Kleiber,JHEProll, Yu Turkin and P Xanthopoulos Max-Planck-Institut fur¨ Plasmaphysik, Greifswald and Garching, Germany Received 22 June 2012, in final form 30 August 2012 Published 21 November 2012 Online at stacks.iop.org/PPCF/54/124009 Abstract An overview is given of physics differences between stellarators and tokamaks, including magnetohydrodynamic equilibrium, stability, fast-ion physics, plasma rotation, neoclassical and turbulent transport and edge physics. Regarding microinstabilities, it is shown that the ordinary, collisionless trapped-electron mode is stable in large parts of parameter space in stellarators that have been designed so that the parallel adiabatic invariant decreases with radius. Also, the first global, electromagnetic, gyrokinetic stability calculations performed for Wendelstein 7-X suggest that kinetic ballooning modes are more stable than in a typical tokamak.
    [Show full text]
  • Lyman Spitzer ______
    Astronomy Cast Episode 207 Lyman Spitzer _____________________________________________________________________ Fraser: Astronomy Cast Episode 207 for Monday November 15, 2010, Lyman Spitzer. Welcome to Astronomy Cast, our weekly facts-based journey through the cosmos, where we help you understand not only what we know, but how we know what we know. My name is Fraser Cain, I'm the publisher of Universe Today, and with me is Dr. Pamela Gay, a professor at Southern Illinois University Edwardsville. Hi, Pamela, how are you doing? Pamela: I’m doing well. How are you doing, Fraser? Fraser: Good... how is your spare bedroom doing? Pamela: My spare bedroom is less overwhelmingly filled with things, but a new shipment is coming soon so please order more t-shirts... and we have skinny-people ones, too! Fraser: Great! So as we mentioned in the last show, we’ve got t-shirts, CDs, posters, all kinds of cool Astronomy Cast related stuff available. You just go to astrogear.org and see what we have on offer... and, yeah, you can buy it and clear out Pamela’s spare bedroom. Pamela: And I have to congratulate our audience because you guys are overwhelmingly thin! It was the most surreal discovery. Smalls and mediums sold out first and that was awesome and odd... Fraser: Lots of kids, too... that’s great. Pamela: Yeah. Fraser: Alright, well time for another action-packed double episode of Astronomy Cast. This week we focus on Lyman Spitzer, a theoretical physicist and astronomer who worked on star formation and plasma physics, and of course this will lead us into next week’s episode where we talk about the mission that bears his name, the Spitzer Space Telescope.
    [Show full text]
  • Nov/Dec 2020
    CERNNovember/December 2020 cerncourier.com COURIERReporting on international high-energy physics WLCOMEE CERN Courier – digital edition ADVANCING Welcome to the digital edition of the November/December 2020 issue of CERN Courier. CAVITY Superconducting radio-frequency (SRF) cavities drive accelerators around the world, TECHNOLOGY transferring energy efficiently from high-power radio waves to beams of charged particles. Behind the march to higher SRF-cavity performance is the TESLA Technology Neutrinos for peace Collaboration (p35), which was established in 1990 to advance technology for a linear Feebly interacting particles electron–positron collider. Though the linear collider envisaged by TESLA is yet ALICE’s dark side to be built (p9), its cavity technology is already established at the European X-Ray Free-Electron Laser at DESY (a cavity string for which graces the cover of this edition) and is being applied at similar broad-user-base facilities in the US and China. Accelerator technology developed for fundamental physics also continues to impact the medical arena. Normal-conducting RF technology developed for the proposed Compact Linear Collider at CERN is now being applied to a first-of-a-kind “FLASH-therapy” facility that uses electrons to destroy deep-seated tumours (p7), while proton beams are being used for novel non-invasive treatments of cardiac arrhythmias (p49). Meanwhile, GANIL’s innovative new SPIRAL2 linac will advance a wide range of applications in nuclear physics (p39). Detector technology also continues to offer unpredictable benefits – a powerful example being the potential for detectors developed to search for sterile neutrinos to replace increasingly outmoded traditional approaches to nuclear nonproliferation (p30).
    [Show full text]