A brief history of Particle Accelerators. and Future By Nawin Juntong 4 March 2014

Transcription

1 A brief history of Particle Accelerators and Future By Nawin Juntong 4 March 2014

2 A brief history of Particle Accelerators A.W. Chao, W. Chou, Reviews of Accelerator Science and Technology Volume 1, World Scientific

3 DC acceleration 1895 Philipp von Lenard, Electron scattering on gases (Nobel prize 1905 for his work on cathode rays). < 100 kev electrons 1906 Rutherford bombards mica sheet with natural alphas and develops the theory of atomic scattering. Natural alpha particles of several MeV 1911 Rutherford publishes theory of atomic structure 1913 Franck and Hertz excited electron shells by electron bombardment (proved Niels Bohr's theory, Nobel prize 1925 for their discovery of the laws governing the impact of an electron upon an atom). Wimshurst-type machines 1919 Rutherford induces a nuclear reaction with natural alphas..rutherford believes he needs a source of many MeV to continue research on the nucleus. This is far beyond the electrostatic machines then existing, but Gamov predicts tunneling and perhaps 500 kev would suffice Cockcroft and Walton start designing an 800 kv generator encouraged by Rutherford 1932 Generator reaches 700 kv and Cockcroft and Walton split lithium atom with only 400 kev protons. They received the Nobel prize in 1951 for their pioneer work on the transmutation of atomic nuclei by artificially accelerated atomic particles Three separate roots Resonant acceleration 1924 Ising proposes time-varying fields across drift tubes. This is resonant acceleration, which can achieve energies above the given highest voltage in the system Wideroe demonstrates Ising s principle with 1 MHz, 25 kv oscillator to make 50 kev potassium ions Lawrence, inspired by Wideroe and Ising, conceives the cyclotron Livingston demonstrates the cyclotron by accelerating hydrogen ions to 80 kev Lawrence s cyclotron produces 1.25 MeV protons and he also splits the atom just a few weeks after Cockcroft and Walton (Lawrence received the Nobel prize in 1939 for the invention and development of the cyclotron and for results obtained with it, especially with regard to artificial radioactive elements) Betatron mechanism 1923 Wideroe, a young Norwegian student, draws in his laboratory notebook the design of the betatron with the well-known 2-to-1 rule. Two year later he adds the condition for radial stability but does not publish Later in Aachen, Wideroe make a model betatron, but it does not work. Discouraged he changes course and builds the linear acceleration mentioned in Table Kerst re-invents the betatron and builds the first working machine for 2.2 MeV electrons Kerst builds the world s largest betatron of 300 MeV. P.J. Bryant, A brief history and review of accelerator, CERN

4 The birth of an era Ernest Rutherford discovers the nuclear disintegration by bombarding nitrogen with alpha particles from natural radioactive substances. Later he calls for a copious supply of particles more energetic than those from natural sources. The particle accelerator era is born. In this equipment, nitrogen atoms were converted into oxygen atoms, when in collision with alpha particles from a source in inside the horizontal enclosed tube. Protons ejected by nitrogen when forming oxygen were detected at the rectangular window at the end of the tube Rutherford's transmutation apparatus Hunterian Museum & Art Gallery collections, catalogue number GLAHM

5 Rutherford s statement in address to the Royal Society (1927) A few years later in 1927 Rutherford, in his presidential address to the Royal Society, made a strong request for higher energy nuclear probes. It has long been my ambition to have available for study a copious supply of atoms and electrons which have an individual energy far transcending that of the α and β particles from radioactive bodies. I am hopeful that I may yet have my wish fulfilled. Rutherford s statement became a challenge to invent higher energy particle accelerators A race for higher energy particle accelerators involved an early competition between electrostatic machines, but electric breakdown was a fundamental limitation to high voltages. Meanwhile, it had already been realized by a few that another solution that avoided very high voltages was to use time-dependent accelerating fields.

6 Gustav Ising published an linear accelerator concept Gustav Ising (1924) published an accelerator concept with voltage waves propagating from a spark discharge to an array of drift tubes Voltage pulses arriving sequentially at the drift tubes produce accelerating fields in the sequence of gaps. But Ising was unable to demonstrate the concept.

7 World s first accelerator Rolf Wideroe, Norwegian graduate student at Aachen University discovered Ising s 1924 publication in the university library Four year after Ising s concept, Rolf Wideroe builds the world s first linac in an 88-cm long glass tube in Aachen, Germany. Wideroe simplified Ising s concept by replacing the spark gap with an ac oscillator For his PhD thesis Wideroe built and demonstrated a simple linac, which had one drift tube between two accelerating gaps

8 World s first accelerator Wideroe applied a 25-KV, 1 MHz AC voltage to the drift tube between two grounded electrodes. The beam experienced an accelerating voltage in both gaps. He accelerated Na and K beams to 50 kev kinetic energy equal to twice the applied voltage. This is not possible using electrostatic voltages My little machine was a primitive precursor of this type of accelerator which today is called a linac for short. However, I must now emphasize one important detail. The drift tube was the first accelerating system which had earthed potential on both sides, i.e. at both the particles entry and exit, and was still able to accelerate the particles exactly as if a strong electric field was present. Rolf Wideroe (From The Infancy of Particle Accelerators, Life and Work of Rolf Wideroe ed. Pedro Waloschek )

9 Van de Graaff generator Robert Van de Graaff invents the Van de Graaff generator at Princeton University. He also constructs the first tandem accelerator (two generators in series) in 1959 at Chalk River. 1931, the large Van de Graaff generator was constructed

10 Cyclotron Inspired by Rolf Wideroe's linac in a vacuum tube, Ernest Lawrence invents the cyclotron at the University of California, Berkeley. He and his student Stanley Livingston build a cyclotron only 4 inches in diameter Lawrence s cyclotron produces 1.25 MeV protons and he also splits the atom just a few weeks after Cockcroft and Walton

11 1932- Cockcroft-Walton accelerator John Cockcroft and Ernest Walton invent the Cockcroft-Walton electrostatic accelerator at the Cavendish Laboratory. This accelerator produces the first man-made nuclear reaction. Cockcroft, Rutherford, and Walton in 1932, shortly after they accelerated protons against a lithium target, splitting the lithium nucleus into two alpha particles, i.e., helium nuclei. This demonstrated not only the transmutation of elements, but also Einstein's formula E=mc 2, since a slight loss of mass produced energetic alpha particles

12 Klystron Russell and Sigurd Varian and William Hasen invent the kystron, a highfrequency amplifier for generating microwaves, at Stanford University. A similar device is proposed by Agnesa Arsenjewa-Heil and Oskar Heil in In 1948 they founded Varian Associates (along with Hansen and Ginzton) to market the klystron and other inventions Varian Semiconductor Equipment Associates Varian Medical Systems Varian, Inc Sold the Electron Device Business and formed Communications & Power Industries, Inc (CPI) acquired by Agilent Technologies

13 Betatron Donald Kerst at the University of Illinois constructs the first betatron, proposed by Joseph Slepian and others in the 1920s Kerst builds the world s largest betatron of 300 MeV. 2 nd 25 MeV 300 MeV 1 st 2.3 MeV

14 1943 Synchrotron 1944 Phase stability Marcus Oliphant develops the concept for a new type of accelerator, later named the synchrotron by Edwin McMillan Vladimir Veksler at the Lebedev Institute of Physics and later Edwin McMillan at the University of California, Berkeley, independently discover the principle of phase stability, a cornerstone of modern accelerators. The principle is first demonstrated on a modified cyclotron in 1946 at Berkeley.

15 Technical difficulty Ising and Wideroe established principle of resonance acceleration Particles can gain arbitrarily high kinetic energy from successive traversals through the same accelerating fields with moderate voltages. Particles acquire a small energy increment with each traversal No basic limit to maximum kinetic energy. Method can be applied to linear accelerators (linac) or to circular accelerators (cyclotron or synchrotron). But with low (1-MHz) frequencies available at that time, linacs for faster protons and electrons had impractically large gap-to-gap spacings. The gap-to-gap spacing is v/2f so high-velocity particles require high oscillator frequency to obtain satisfactory energy gain per gap. At least a few hundred MHz were wanted, but RF frequencies available then were no more than 10 MHz. Higher frequency microwave sources were unavailable until after WWII, a benefit of radar developments for the war. The first proton and electron linacs were built after WWII

16 World War II

17 1946 Electron linac William Walkinshaw and his team at Malvern in the U.K. build the first traveling wave electron linac powered by a magnetron. William Webster Hansen and his team independently build a similar electron linac at Stanford University a few months later based on klystron and GeV energy.

18 1946 Synchrotron radiation Frank Goward constructs the first electron synchrotron in the U.K. This is followed by one built by General Electric in the U.S. where synchrotron radiation is first observed, open a new era of accelerator-based light sources. Langmuir is credited as recognizing it as synchrotron radiation or, as he called it, "Schwinger radiation." Subsequent measurements by the GE group began the experimental establishment of its spectral and polarization properties. Characterization measurements were also carried out in the 1950s at a 250-MeV synchrotron at the Lebedev Institute in Moscow The radiation is seen as a small spot of brilliant white light by an observer looking into the vacuum tube 350 University of Glasgow

19 1947 Drift tube linac Luis Alvarez builds the first drift tube linac for accelerating protons at the University of California, Berkeley. L. Alvarez and coworkers at the Lawrence Berkeley Radiation Laboratory developed a proton linear accelerator based on injection of 200 MHz RF wave into a resonant metallic cylindrical cavity containing the wideroe-type drift tube arrangement. - the linac is injected with a 4 MeV electrostatic accelerator - protons are accelerated up to 32 MeV in the Alvarez structure DTLs are nowadays currently used as primary injection stages in hadron linac chains, or as injectors into synchrotrons

20 1952 Strong focusing Ernest Courant, Stanley Livingston and Hartland Snyder at Brookhaven National Laboratory and, independently Nicholas Christofilos earlier in 1950 in Greece discover the principle of strong focusing. Strong focusing and phase stability form the foundation of all modern high-energy accelerator. Weak focusing

21 Kyoto University Research Reactor Institute (KURRI), Osaka, Japan FFAG The first Fixed-Field Alternating Gradient (FFAG) accelerator is commissioned at the Midwestern University Research Association. The concept is invented independently by Tihiro Ohkawa, Andrei Kolomensky and Keith Symon. An earlier variation is conceived by Llewellyn Thomas in 1938.

22 1959 Modern Synchrotron The first two proton synchrotrons using strong focusing PS at CERN and AGS at BNL are built. An electron synchrotron using strong focusing is built earlier in 1954 at Cornell University Milton Livingston builds a Synchrotron capable of accelerating protons to 6.2 GeV called the Bevatron Donald Kerst investigates the collision of particle beams at relativistic energies Scientists at Dubna USSR build a Synchrotron capable of accelerating protons to 10GeV called the Synchrophasotron Scientists at CERN, Geneva, using Alternating - Gradient focusing build a Synchrotron capable of accelerating protons to 28 GeV called the Proton Synchrotron (PS) Scientists at Brookhaven build a Synchrotron capable of accelerating protons to 33GeV called the Alternating - Gradient Synchrotron (AGS). Bevatron Synchrophasotron CERN - PS John Adams with vodka bottle

23 Collider AdA, the first electron-positron collider, is built at Frascati, Italy. It is followed by two electronelectron colliders: Priceton Stanford Collider in the U.S. and VEP-1 in Russia, leading to a continuing evolution of electron-positron colliders and factories around the world The Austrian physicist, Bruno Touschek builds the first storage ring, an electron - positron storage ring, in Italy called Aneii di Accumulazione (AdA), but is too small to be of experimental use.

24 1964 Induction linac Astron, the first induction linac proposed ny Nicholas Christofilos for nuclear fusion, is built at a branch of the Lawrence Radiation Laboratory, later renamed the Lawrence Livermore National Laboratory. the main advantage of induction linacs is their ability to accelerate long-pulse (tens of ns to µs) high-intensity (multi-ka) beams. Another specific feature is the total electrical insulation of the apparatus, the high voltage appearing only inside the induction cells.

25 Beam cooling 1966 Gersh Budker invents electron beam cooling at the Institute for Nuclear Physics in Russia Simon van der Meer invents stochastic beam cooling, a technique enabling cooling of antiproton beams. The proton-antiproton collisions in the SppS in 1981 at CERN lead to the discovery of the Z and W bosons The Dutch physicist Simon van der Meer proposes stochastic cooling. Researchers at SLAC carry out deep inelastic scattering experiments of protons and neutrons and discover the up, down and strange quarks. electron cooling is used to shrink the size of electron beams without removing any particles from the beam, increasing luminosity in hadron colliders.

26 ISR Intersecting Storage Ring, the first large proton-proton collider begins at CERN. Scientists at CERN build the Intersecting Storage Ring (ISR) on the CPS where 26 GeV proton beams are collided. ISR at CERN. (a) Layout of proton synchrotron and two intersecting storage rings: (PS) proton synchrotron, (SR) storage ring, (1) (8) points of intersection of storage rings, (C1) and (C2) channels through which protons (p) are fed into the storage rings. Preliminary acceleration of the protons is carried out in the booster; In the storage rings the protons are additionally accelerated to 31.4 GeV. The arrows indicate the direction of motion of the protons. The proton beams collide in the intersection zones of the storage rings. (b) Detail of intersection of proton beams between sections A and A : (1) structural elements of magnet focusing the proton beams.

27 1970 -RFQ Vladimir Teplyakov and Ilya Kapchinskii invent the radio frequency quadrupole linacs. The first RFQ is built in 1972 at the Institute of High Energy Physics in Russia.

28 FEL John Madey invents and builds the first free electron laser at Stanford University

29 1983 Superconducting magnet technology The Tevatron, the first large accelerator using superconducting magnet technology, is commissioned at Fermilab.

30 1989 Linear collider SLC, the first linear collider proposed by Burton Ritcher, is built at SLAC. The linear collider concept is developed by Maury Tigner in 1965.

31 Desertron 40 TeV, 87 km 1993 Rise and fall of SSC Construction of the Superconducting Super Collider, planned to be the largest accelerator in the world, begin in The project is canceled by the U.S. Congress in The United States had planned the SSC on its own but asked other countries to get involved when the cost began to expand beyond initial expectations. Understandably, other countries were reluctant to fund a project in which they felt no sense of ownership, not having served as designer or host. Congress pulled funding for the SSC in The Department of Energy pulled together a panel to discuss the future. In the end, they decided to throw their weight behind the LHC. The global physics community has kept the lessons of the SSC and the LHC in mind while planning for the next international accelerator project. This time, countries are working together from the beginning. Physicists have already demonstrated this attitude in developing three proposed accelerators: the International Linear Collider, the Compact Linear Collider and a muon collider. At a relatively modest scale, Fermilab has embarked on this path with its proposed new accelerator, Project X. If Congress had not cancelled the US-built Superconducting Super Collider project in 1993, this tunnel in Waxahatchie, Texas, would have held the collider and its superconducting magnets, such as the one shown below at Fermilab. A failure to secure international partners to design and build the project is among the reasons for the SSC's demise.

32 1994 Superconducting RF technology CEBAF, the first large accelerator using superconducting radio frequency technology, is built at the facility later named Jefferson Laboratory.

33 2005 X-ray FEL FLASH, the first VUV and soft x-ray free electron laser user facility is built at DESY in Germany.

34 LHC The Large Hadron Collider at CERN, with 27 km circumference, begins operation.

35 Future Advanced concepts Plasma and laser acceleration tantalizes one s imagination. An acceleration gradient 1000 times higher than that of conventional means has been demonstrated. These advanced concepts challenge future accelerator builders. Leemans/Esarey(2009):Laser-driven plasma-wave electron accelerators.physicstoday

36 There are many more to come Thank you

37 References A.W. Chao, W. Chou, Reviews of Accelerator Science and Technology Volume 1, World Scientific P.J. Bryant, A brief history and review of accelerator, CERN E. J. N. Wilson, FIFTY YEARS OF SYNCHROTRONS, CERN Matt Luffoni, The history and revolution of Synchrotron radiation sources Thomas Wangler, Linear Accelerators Principles, History, and Applications. John P. Wefel, Cosmic Rays and High Energy Physics. Ron Ruth, Man-Made Accelerators (Earth-Based), SLAC. Sergei Nagaitsev, Electron Cooling, Physics 598ACC lectures, 2007 Summer Term, Fermi. Eugene S. Evans, Brief Overview of Wakefield Acceleration, University of California, Berkeley. F. M eot, An introduction to particle accelerators. Shinji Machida, Fixed Field Alternating Gradient (FFAG) Accelerator J. de Mascureau, INDUCTION LINACS Leemans/Esarey(2009):Laser-driven plasma-wave electron accelerators.physicstoday Alessandra Lombardi, Radio Frequency Quadrupole Peter Schm user, Free Electron Lasers