DOCSLIB.ORG

Accelerators and Medicine

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Accelerators and Medicine Journal of the Korean Physical Society, Vol. 50, No. 5, May 2007, pp. 1385∼1389 Review Articles Accelerators and Medicine William T. Chu∗ EO Lawrence Berkeley National Laboratory, Berkeley, California, U.S.A. (Received 22 November 2006) In 1930 Ernest Orlando Lawrence at the University of California, Berkeley invented the cy- clotron, which accelerated protons to 80 keV using less than 1 kV on a semi-circular “dee.” The 60-Inch (150-cm) Cyclotron (1939) that accelerated deuterons to 19 MeV, enabled the first ther- apeutic applications anywhere of artificially produced radioisotopes on human patients, thereby a new medical modality called nuclear medicine was born. Around the world, there are about 100 isotope-producing cyclotrons (accelerating protons, and much less frequently deuterons, to energies in the range of 15-20 MeV). After WWII, Lawrence completed the 184-Inch (4.7-m) Synchrocy- clotron that produced 340-MeV protons. The synchrocyclotrons in Berkeley and Uppsala, together with the Harvard cyclotron, would perform pioneering work in treatment of human cancer using accelerated hadrons. At the 184-Inch, in 1954 Cornelius Tobias and John Lawrence performed the first therapeutic exposure of human patients to hadron (deuteron and helium ion) beams. Clinical trials to treat human cancer using helium ions took place at the 184-Inch and the Bevalac, where trials using heavier ions including carbon, neon, silicon and argon ions were carried out to exploit their biological advantages over proton beams. Aside from the Berkeley trials, other clinical trials have been conducted at more than a dozen physics accelerators around the world. There are now proton and carbon-ion accelerator facilities dedicated for medical use around the world. PACS numbers: 29.20.Hm, 29.20.Lq, 87.52.Df, 87.52.Ln, 87.53.-j Keywords: Accelerator, Cyclotron, Synchrotron, Cancer treatment, Nuclear medicine I. INVENTION OF CYCLOTRON ated deuterons to 19 MeV. It was housed in the Crocker Laboratory, where scientists first made transmutations of some elements, discovered several transuranic ele- The invention of the cyclotron by Ernest Orlando ments, and created hundreds of radioisotopes of known Lawrence at the University of California, Berkeley elements. At the Crocker Laboratory the new medical seventy-five years ago profoundly changed the way we treat human diseases. Lawrence conceived the idea of the cyclotron early in 1929 after reading an article by Rolf Wider¨oeon high-energy accelerators [1]. In the spring of 1930 one of his students, Nels Edlefsen, constructed two crude models of a cyclotron [2]. Later in the fall of the same year, another student, M. Stanley Livingston, constructed a 13-cm diameter model (Fig. 1) that had all the features of early cyclotrons, accelerating protons to 80 keV using less than 1 kV on a semi-circular accel- erating electrode, now called the “dee” [3]. Following the discovery by J. D. Cockcroft and E. T. S. Walton of how to produce larger currents at higher voltages [4], Lawrence constructed the first two- dee 27-Inch (69-cm) Cyclotron, which produced protons and deuterons of 4.8 MeV. The 27-Inch Cyclotron was used extensively in early investigations of nuclear re- actions involving neutrons and artificial radioactivity. In 1939, working with William Brobeck, Lawrence con- structed the 60-Inch (150-cm) Cyclotron, which acceler- Fig. 1. The first cyclotron made by Lawrence and Liv- ingston (1930). ∗E-mail: [email protected] -1385- -1386- Journal of the Korean Physical Society, Vol. 50, No. 5, May 2007 modality called nuclear medicine was born, which used 60-Inch Cyclotron. Their research discovered the nature radioisotopes for diagnosis and treatment of human dis- of decompression sickness, known as the “the bends,” eases. In 1939 Lawrence was awarded the Nobel Prize that many military aviators suffered when flying at high in Physics, and later Element 103 was named “Lawren- altitudes without pressurized suits [5]. It is interesting to cium” in his honor. note that after more than a half century later, 81mKr gas Just before WWII, Lawrence and Brobeck designed is still used at hospitals to yield functional images of pul- the 184-inch cyclotron, but the war prevented the monary ventilation. Now it became routine for nuclear building of this machine. Immediately after the war medicine procedures that use radioisotopes to provide ended, the Veksler-McMillan principle of phase stability diagnostic information about the functioning of a per- was put forward, which enabled the transformation of son’s specific organs, or to treat diseases. The thyroid, conventional cyclotrons to successful synchrocyclotrons. bones, heart, liver and many other organs can be readily When completed, the 184-Inch Synchrocyclotron pro- imaged, and disorders in their function revealed. It is duced 340-MeV protons. Soon after, more modern syn- estimated that 15 to 20 million nuclear medicine imag- chrocyclotrons were built around the globe, notably at ing and therapeutic procedures are performed every year Columbia University, Carnegie Institute of Technology, around the world, and demand for radioisotopes is in- and University of Chicago in the United States, and an- creasing rapidly. In developed countries (about a quarter other in Uppsala, Sweden. The synchrocyclotrons in of world population) the frequency of diagnostic nuclear Berkeley and Uppsala, together with the Harvard cy- medicine procedures performed is approximately two per clotron, would perform pioneering work in treatment of 100 persons per year, and the frequency of therapy with human cancer using accelerated hadrons. radioisotopes is about one tenth of this. In the 1950s larger synchrotrons were built in the GeV A radioisotope used in Single Photon Emission Com- region at Brookhaven (3-GeV Cosmotron) and at Berke- puted Tomography (SPECT) must emit gamma rays of ley (6-GeV Bevatron), which produced antiprotons and sufficient energy to escape from the body yet it must antineutrons, many of the transuranic nuclei, and many have a halflife short enough for most of it to decay away excited states of hadrons. Today most of the world’s soon after imaging is completed. A positron emitter largest accelerators are synchrotrons, such as the 1-TeV with a similarly short halflife is needed in Positron Emis- Tevatron at Fermilab near Chicago and the 450-GeV Su- sion Tomography (PET). PET’s most important clinical per Proton Synchrotron (SPS) at CERN in Switzerland, role is in oncology, where fluorodeoxy glucose (FDG) is and all are direct descendents of Lawrence’s cyclotron used (incorporating 18F as the tracer), due to its accu- invented 75 years ago. racy in detecting and evaluating most cancers in a non- invasive way. It is also used in cardiac and brain imag- ing. Positioning of the radiation source within the body is the fundamental difference between nuclear medicine II. BEGINNING OF NUCLEAR MEDICINE imaging and other imaging techniques such as X-rays. Gamma imaging by either SPECT or PET provides a Lawrence’s interest in building accelerators centered, view of the position and concentration of the radioiso- of course, on nuclear physics; but from the onset he was tope within the body. Organ malfunction can be indi- keenly aware of their important applications in medicine. cated if the isotope is either partially taken up in the To study radiation in medicine, Lawrence brought to organ (a cold spot), or taken up in excess (a hot spot). Berkeley his physician brother, John Hundale Lawrence, If a series of images is taken over a period of time, an M.D., from Yale School of Medicine, who soon demon- unusual pattern or rate of isotope movement could indi- strated the isotope-making cyclotron’s worth in disease cate malfunction in the organ. Nuclear fission reactors research. John Lawrence became Director of the Divi- produce the bulk of medical radioisotopes [6], but iso- sion of Medical Physics at the University of California, topes of very short halflives, especially those for PET, Berkeley. Starting in 1936, John Lawrence operated a are produced by cyclotrons located near PET machines clinic to treat leukemia and polycythemia patients with in hospitals. Around the world, there are about 100 radioactive phosphorus produced at Crocker Laboratory, isotope-producing cyclotrons (accelerating protons, and then the site of the 60-Inch Cyclotron. These were much less frequently deuterons, to energies in the range the first therapeutic applications anywhere of artificially of 15 – 20 MeV). The typical beam power of such a cy- produced radioisotopes on human patients. Thus John clotron is of the order of 15 kW. In the foreseeable future, Lawrence became the “Father of Nuclear Medicine.” >100-MeV cyclotrons, and linacs, with beam power ten Ernest Lawrence himself became a consultant to the In- times greater, will be required to produce isotopes for stitute of Cancer Research at Columbia University. newer nuclear medicine procedures. One of the earliest biomedical uses of radioactive el- Radioisotopes produced at cyclotron facilities for var- ements was research conducted during WWII by John ied nuclear medicine applications include: Positron emit- Lawrence and Cornelius Tobias, another student of ters 11C, 13N, 15O, and 18F, which are used in PET to Ernest Lawrence. They used radioactive nitrogen, argon, study brain physiology and pathology, in particular to krypton, and xenon gases, which were produced at the localize epileptic focus, and in dementia, psychiatry and Accelerators and Medicine – William T. Chu -1387- neuropharmacology
Load more

Recommended publications
  • October 1986
    C Fermi National Accelerator Laboratory Monthly Report October 1986 'Ht», i't:.t"tS?t M Fermi/ab Report is published monthly by the Fermi National Accelerator Laboratory Technical Publications Office, P.O. Box 500, MS 107, Batavia, IL, 60510 U.S.A. (312) 840-3278 Editors: R.A. Carrigan, Jr., F.T. Cole, R. Fenner, L. Voyvodic Contributing Editors: D. Beatty, M. Bodnarczuk, R. Craven, D. Green, L. McLerran, S. Pruss, R. Vidal Editorial Assistant: S. Winchester The presentation of material in Fermilab Report is not intended to substitute for nor preclude its publication in a professional journal, and references to articles herein should not be cited in such journals. Contributions, comments, and requests for copies should be addressed to the Fermilab Technical Publications Office. 86/8 Fermi National Accelerator Laboratory 0090.01 011 the cover: M. Stanley Livingston (May 25, 1905 - August 25, 1986) and Ernest 0. Lawrence beside one of the earliest cyclotrons ca. 1933. A remembrance of M.S. Livingston begins on page 21 of this issue. Operated by Universities Research Association, Inc., under contract with the United States Department of Energy Table of Contents Who's Who in the Upcoming Fixed-Target Run? Mark W. Bodnarczuk Saturday Morning Physics: a Report Card 17 Drasko Jovanovic, Barbara Grannis, and Marjorie Bardeen M. Stanley Livingston; 1905 - 1986 21 F.T. Cole Manuscripts, Notes, Lectures, and Colloquia Prepared or Presented from September 21 to October 20, 1986 23 Dates to Remember inside back cover Who's Who in the Upcoming Fixed-Target Physics Run? Mark W. Bodnarczuk Introduction The purpose of this article is to identify the 16 experiments and major test beam programs that will operate during the upcoming fixed-target run scheduled to begin in the middle of March 1987.
    [Show full text]
  • A Brief History and Review of Accelerators
    A BRIEF HISTORY AND REVIEW OF ACCELERATORS P.J. Bryant CERN, Geneva, Switzerland ABSTRACT The history of accelerators is traced from three separate roots, through a rapid development to the present day. The well-known Livingston chart is used to illustrate how spectacular this development has been with, on average, an increase of one and a half orders of magnitude in energy per decade, since the early thirties. Several present-day accelerators are reviewed along with plans and hopes for the future. 1 . INTRODUCTION High-energy physics research has always been the driving force behind the development of particle accelerators. They started life in physics research laboratories in glass envelopes sealed with varnish and putty with shining electrodes and frequent discharges, but they have long since outgrown this environment to become large-scale facilities offering services to large communities. Although the particle physics community is still the main group, they have been joined by others of whom the synchrotron light users are the largest and fastest growing. There is also an increasing interest in radiation therapy in the medical world and industry has been a long-time user of ion implantation and many other applications. Consequently accelerators now constitute a field of activity in their own right with professional physicists and engineers dedicated to their study, construction and operation. This paper will describe the early history of accelerators, review the important milestones in their development up to the present day and take a preview of future plans and hopes. 2 . HISTORICAL ROOTS The early history of accelerators can be traced from three separate roots.
    [Show full text]
  • A Brief History and Review of Accelerators
    A BRIEF HISTORY AND REVIEW OF ACCELERATORS P.J. Bryant CERN, Geneva, Switzerland ABSTRACT The history of accelerators is traced from three separate roots, through a rapid development to the present day. The well-known Livingston chart is used to illustrate how spectacular this development has been with, on average, an increase of one and a half orders of magnitude in energy per decade, since the early thirties. Several present-day accelerators are reviewed along with plans and hopes for the future. 1 . INTRODUCTION High-energy physics research has always been the driving force behind the development of particle accelerators. They started life in physics research laboratories in glass envelopes sealed with varnish and putty with shining electrodes and frequent discharges, but they have long since outgrown this environment to become large-scale facilities offering services to large communities. Although the particle physics community is still the main group, they have been joined by others of whom the synchrotron light users are the largest and fastest growing. There is also an increasing interest in radiation therapy in the medical world and industry has been a long-time user of ion implantation and many other applications. Consequently accelerators now constitute a field of activity in their own right with professional physicists and engineers dedicated to their study, construction and operation. This paper will describe the early history of accelerators, review the important milestones in their development up to the present day and take a preview of future plans and hopes. 2 . HISTORICAL ROOTS The early history of accelerators can be traced from three separate roots.
    [Show full text]
  • Introduction to Accelerators: Evolution of Accelerators and Modern Day Applications
    Lecture 1 Introduction to Accelerators: Evolution of Accelerators and Modern Day Applications Sarah Cousineau, Jeff Holmes, Yan Zhang USPAS January, 2011 What are accelerators used for? • Particle accelerators are devices that produce energetic beams of particles which are used for – Understanding the fundamental building blocks of nature and the forces that act upon them (nuclear and particle physics) – Understanding the structure and dynamics of materials and their properties (physics, chemistry, biology, medicine) – Medical treatment of tumors and cancers – Production of medical isotopes – Sterilization – Ion Implantation to modify the surface of materials • There is active, ongoing work to utilize particle accelerators for – Transmutation of nuclear waste – Generating power more safely in sub-critical nuclear reactors Accelerators by the Numbers World wide inventory of accelerators, in total 15,000. The data have been collected by W. Scarf and W. Wiesczycka (See U. Amaldi Europhysics News, June 31, 2000) Category Number Ion implanters and surface modifications 7,000 Accelerators in industry 1,500 Accelerators in non-nuclear research 1,000 Radiotherapy 5,000 Medical isotopes production 200 Hadron therapy 20 Synchrotron radiation sources 70 Nuclear and particle physics research 110 The most well known category of accelerators – particle physics research accelerators – is one of the smallest in number. The technology for other types of accelerators was born from these machines. Nuclear and Particle Physics • Much of what we know about
    [Show full text]
  • Particle Accelerators and Discoveries in Elementary Particle Physics
    2280 PARTICLE ACCELERATORS AND DISCOVERIES IN ELEMENTARY PARTICLE PHYSICS Lawrence W. Jones Randall Laboratory of Physics, University of Michigan Ann Arbor, Michigan 48109-1120 Abstract Some discoveries in elementary particle physics are recounted from personal and his- torical perspective with particular reference to their interaction with particle accelerators. The particular examples chosen include the C/J, the T, and the study of nucleon con- stituents with inelastic electron scattering. Precurser experiments are cited together with the better known discoveries. 2281 PARTICLE ACCELERATORS AND DISCOVERIES IN ELEMENTARY PARTICLE PHYSICS Lawrence W. Jones* Randall Laboratory of Physics, University of Michigan Ann Arbor, Michigan 48109-1120 Dr. Month asked me to prepare a talk on high energy physics discoveries and their relationship to particle accelerators. No particular time period was specified~ however, high energy physics as a field is less than forty years old. This historical subject was a challenge for me as there was clearly far too much to cover in a comprehensive manner in just one hour. Therefore, I was forced to pick and choose. I am not an historian of physics, and I have not made a systematic study of the recent history of particle physics. Rather I am a physicist who is now becoming old enough to have "been there" when some of these discoveries were made. I have used as one source for this talk the material contained in a report prepared for a larger document "Physics in the 1980's" edited by Dr. Brinkman. Martin Perl of Stanford has chaired a subpanel on elementary particle physics of that task force, on which I served.
    [Show full text]
  • Nobel Laureates and Twentieth-Century Physics Mauro Dardo Index More Information
    Cambridge University Press 0521540089 - Nobel Laureates and Twentieth-Century Physics Mauro Dardo Index More information Index Abrikosov, Alexei A., 474 American Physical Society, 395 Armstrong, Neil, 279 biographical notes on, 466 Amp`ere,Andr´e-Marie,19, 28 Arnold, Harold, 163 Nobel Prize (2003) to, 462 Anderson, Carl David, 58, 183, 184, 187, Arrhenius, Svante, 34, 69–70, 120, superconductivity, 464–465 194, 196, 226, 231–234, 275, 422, 126–139, 302 Academy of Sciences, French, 13, 43, 44, 470 Aston, Francis William, 82, 200 138, 139, 165, 316, 411, 413 biographical notes on, 195–197 mass spectrograph, 121–122 Academy of Sciences, Prussian, 104–105, muon, 195 astronomy, 329, 414 115, 122, 123, 128, 187 Nobel Prize (1936) to, 193 Astrophysical Journal, 351, 415 Academy of Sciences, Russian, 268, 284, positron, 183, 197 astrophysics, 279, 302, 319, 329, 414, 349, 447, 466–467 Anderson, Philip Warren, 328, 344–345, 458, 475 Academy of Sciences, Soviet Union, see 348, 356, 434, 472 asymptotic freedom, 406 Academy of Sciences, Russian biographical notes on, 345–346 AT&T, 6, 163, 278 Accademia dei Lincei, 348 challenge of reductionism by, 347–349 Atkinson, Robert, 303 accelerators, see particle accelerators condensed-matter physics, 346–347 atom, 17, 25, 26–27, 475 AGS (BNL), 272, 286, 313, 337, 363, 398 Nobel Prize (1977) to, 340–341 Bohr’s model of, 91 Alembert Le Rond Jean d’, 14 Anderson localisation, 344–347, 434 nuclear, 77, 80, 81, 90–91 Alferov, Zhores Ivanovich, 447, 474 Anderson model, 346 plum pudding model of, 81 biographical
    [Show full text]
  • M. Stanley Livingston
    NATIONAL ACADEMY OF SCIENCES M I L T O N S T A N L E Y L IVIN G STON 1905—1986 A Biographical Memoir by E R N E S T D. COURANT Any opinions expressed in this memoir are those of the author(s) and do not necessarily reflect the views of the National Academy of Sciences. Biographical Memoir COPYRIGHT 1997 NATIONAL ACADEMIES PRESS WASHINGTON D.C. Courtesy of Brookhaven National Laboratory MILTON STANLEY LIVINGSTON May 25, 1905–August 25, 1986 BY ERNEST D. COURANT N JANUARY 9, 1932, in Berkeley, California, a magnetic Oresonance accelerator (cyclotron) built by M. Stanley Livingston accelerated protons to 1.22 MeV (million elec- tron volts), the first time that particles with energies ex- ceeding one million volts had been produced by man. Twenty years later, in May 1952, the Cosmotron at Brookhaven Na- tional Laboratory, whose construction Livingston had initi- ated, became the world’s first billion-volt (GeV) accelera- tor. By the time of his death in 1986 the world record had gone up by three more orders of magnitude to 900 GeV, thanks to an innovation by Livingston and others. Milton Stanley Livingston was born in Broadhead, Wis- consin, on May 25, 1905, the son of Milton McWhorter Livingston and his wife Sarah Jane, née Ten Eyck. His fa- ther was a divinity student who soon became minister of a local church. When Stanley was about five years old the family moved to southern California, where his father be- came a high school teacher and later principal, having found that a minister’s salary was inadequate to support a growing family.
    [Show full text]
  • EARLY ACCELERATORS and THEIR BUILDERS* Edwin M
    EARLY ACCELERATORS AND THEIR BUILDERS* Edwin M. McMillan Lawrence Berkeley Laboratory University of California Berkeley, California 94720 I would like to begin by explaining that what I am going to give is not an address, it is a slide show. I started with the idea of covering accelerators and their builders and soon, realizing the time limits, I had to limit it to early accelerators, and then I had to pretty well leave out accelerators and just con- centrate on builders, and then I realized that there wasn't time to say very much, so I just put in a whole lot of slides, mostly involving people. There are a few actual pictures of machines in here which got in by accident. Actually what happened was, I got in about as many slides as I thought I could show, but they didn't quite fill the box I had, so I shoved in a few more just so they wouldn't rattle around in the box. That's how the accelerators got in. The inception of the idea of accelerators for nuclear purposes I would put around 1930, centering around 1930; take a few years before and a few after, and you'll find that most of the ideas, the basic methods of accelerating, started in that period. The basic types of accelerators might be classified as first, the simplest, those that accelerate simply by application of an electrical potential difference, so that an ion falls through a certain potential dif- ference and acquires a certain energy; then there is the resonance type of accelerator in which one succes- sively applies an impulse which is properly timed; and the third general type is the induction accelerator which works something like a transformer, typified by the betatron, or the linear induction accelerator designed by Christofilos.
    [Show full text]
  • Lecture 1A, Introduction to Accelerators
    Lecture 1a Introduction to Accelerators Stuart Henderson Jeff Holmes Yan Zhang USPAS, January 2009 What are accelerators used for? • Particle accelerators are devices that produce energetic beams of particles which are used for – Understanding the fundamental building blocks of nature and the forces that act upon them (nuclear and particle physics) – Understanding the structure and dynamics of materials and their properties (physics, chemistry, biology, medicine) – Medical treatment of tumors and cancers – Production of medical isotopes – Sterilization – Ion Implantation to modify the surfaces of materials – National Security: cargo inspection, … • There is active, ongoing work to utilize particle accelerators for – Transmutation of nuclear waste – Generating power more safely in sub-critical nuclear reactors Accelerators by the Numbers World wide inventory of accelerators, in total 15,000. The data have been collected by W. Scarf and W. Wiesczycka (See U. Amaldi Europhysics News, June 31, 2000) CtCategory NbNumber Ion implanters and surface modifications 7,000 Accelerators in industry 1,500 Accelerators in non-nuclear research 1,000 Radiotherapy 5,000 Medical isotopes production 200 Hadron therapy 20 Synchrotron radiation sources 70 NlNuclear an d par tilhiticle physics research 110 Nuclear and Particle Physics • Much of what we know about the subatomic world is from experiments enabled by particle accelerators • The first “high-energy” accelerator, made by Cockroft and Walton, was immediately used to understand the atomic nucleus. They made the first artificially produced nuclear reaction: p+Li -> 2 He • Early accelerator developments were driven by the quest for higher and higher particle energies, which in turn was driven by developments in nuclear physics (through the 1960s) and then elementary particle physics (1960s- onward) • The largest accelerator is beginning operation at CERN.
    [Show full text]
  • Report on the Dedication of He Cosmotron and the Conference On
    cram/23 Rome, 9 January 1953. EUROPEAN COUNCIL FOR NUCLEAR RESEARCH REPORT ON THE DEDICATION OF THE COSMOTRON AND THE CONFERENCE ON HIGH ENERGY ACCELERATORS, BROOKHAVEN, 15-17 DECEMBER I952 AND THE THIRD ANNUAL CONFERENCE CE HIGH ENERGY PHYSICS ROCHESTER, 18-20 DECEMBER 1952 by E. Amaldi. Following the decision taken by the Executive Group in Paris on 8 November 1952 to accept the invitation conveyed to CERN by the U.S. Atomic Energy Commission and Associated Universities Inc., Prof. C.J. Bakker, Mr. 0. Dahl and myself went to Brookhaven to attend the Dedication of the Cosmotron and the Conference on high energy accelerators. The Dedication ceremonies started on 15 December at 10.45 a.m. Welcome addresses to the many guests were delivered by Mr. Lloyd Berkner, President of Associated Universities Inc., Mr. E.L. Van Horn, Brookhaven ‘Area Manager and by Dr. L.J. Haworth, Director of Brookhaven National Laboratory. In the afternoon, the guests were divided in small groups and visited the Cosmotron under the guidance of physicists and engineers who gave explanations on the operation of the different parts of this master piece of modern electrical engineering and technique. Afterwards, Dr. G.B. Collins, Chairman of Accelerator Department of Brookhaven National Laboratory, delivered a speech on the principle and features of the Cosmotron and dedicated this machine to the Enlightment and Education of Mankind. This was followed by a speech in which Mr. H.D. Smyth, Commissioner of U.S. A.E.C., discussed the difficult and important problem of distin guishing and setting limits between secret and open research.
    [Show full text]
  • Saptaparnee Chaudhuri University of South Carolina Dept
    Saptaparnee Chaudhuri University of South Carolina Dept. of Physics and Astronomy 1 WORKING OF LAWRENCE’S CYCLOTRON APPLICATIONS AND LIMITATIONS OF CYCLOTRON THE SYNCHROCYCLOTRON THE SYNCHROTRON 2 LAWRENCE’S CYCLOTRON In 1929, Ernest Lawrence developed the first circular accelerator This cyclotron was only 4 inches in diameter, and contained two D- shaped electrodes separated by a small gap An oscillating voltage created an electric field across the small gap, which accelerated the particles as they went around the accelerator 3 WORKING OF THE CYCLOTRON 4 MATHEMATICS OF A CYCLOTRON The proton moves in a circular path of radius: r = mv/qB Frequency f = qB/2πm Resonance condition f = fosc Or qB = 2πmfOSC 5 M. Stanley Livingston and Ernest O.Lawrence, with their 27-inch cyclotron at Berkeley Radiation Laboratory. (Courtesy Lawrence Berkeley National Laboratory) 6 APPLICATIONS OF THE CYCLOTRON Important research tools in nuclear physics. Used for medical purposes e.g. radiation surgery and therapy. The separated sector cyclotron in Vancouver, provides 600 MeV negative hydrogen ions and it is the largest of all cyclotrons. The picture shows the gap inside which the ions are accelerated. 7 LIMITATIONS OF THE CYCLOTRON Cannot accelerate neutral particles. Not useful in accelerations of electrons. With increased velocity, the beam gets out of phase with the oscillating electric field. 8 The radius of curvature for a particle moving relativistically in a static magnetic field is Relativistic cyclotron frequency is 9 SYNCHROCYCLOTRON Only one dee is used instead of two. the frequency of the driving RF electric field is varied to compensate for relativistic effects as the particles' velocity begins to approach the speed of light.
    [Show full text]
  • Highlights from Rhic Plus Some Earlier Bnl Highlights in Subnuclear Physics
    Subnuclear Physics: Past, Present and Future Pontifical Academy of Sciences, Scripta Varia 119, Vatican City 2014 www.p as.va/content/dam/accademia/pdf/sv119/sv119-tannenbaum.pdf Highlights-BNL-RHIC 1 Highlights from RHIC Plus Some Earlier B N L H i g h l iHighlightsghts in S fromubn RHICuclea r Phys ics P MICHAEL J. T ANNENBAUM * Brookhaven National Laboratory Upton, NY 11973 USA A new periodic table for the 21st Century In the 20th century, the periodic table, which was invented in the 19th century, was understood using quantum mechanics, atomic, nuclear and subatomic physics; and many elements were added (Figure 1a). Also in the 20th century, the discovery of a whole new subnuclear world of physics totally changed our view of nature and led to a new periodic table to be understood (Figure 1b). The neutrons and protons, of which atomic nuclei are composed, are themselves Figure 1. a) (left) Periodic Table of the Chemical Elements at end of 20th Century (LANL 2011). b) (right) 21st century periodic table of the Quarks and Leptons (Fermions) and force carriers (Bosons) (FNAL 2011) composed of the subconstituent up (u) and down (d) quarks which are held together by gluons, the quanta of the strong interaction in a theory called Quantum Chromodynamics or QCD (QCD 1983). The quarks have electric charges which are a fraction 2/3 (u), -1/3 (d) of the proton charge. QCD has three new charges called colors, e.g. red, green, blue; and in sharp distinction to elctromagnetism, whose quantum, the photon, carries no electric charge, the gluons of QCD are charged and therefore couple to each other.
    [Show full text]