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Particle Accelerators: An introduction

Lenny Rivkin Swiss Institute of Technology Lausanne (EPFL) Paul Scherrer Institute (PSI) Switzerland

Introduction to Accelerators, African School of , KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL PSI

EPFL

CERN

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL PSI

EPFL

CERN PSI

EPFL

CERN PSI

EPFL

CERN

The Role of Accelerators in Physical and Life Sciences

“It is an historical fact that scientific revolutions are more often driven by new tools than by new concepts”

Freeman Dyson

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Particle beams: main uses (protons, , , neutrons, muons, neutrinos etc.)

Research in basic subatomic physics

Analysis of physical, chemical and biological samples

Modification of physical, chemical and biological properties of matter

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Accelerators in the world New Applications Total number ~ 30’000 growing at about 10% per year New technologies

Research 5% Medicine 35%

Industry 60%

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L.H. Rivkin, Dosch PSI &, DESYEPFL th Introduction to Accelerators, AfricanR. W. School Hamm, of Physics, 9 KNUST,ICFA Kumasi,Seminar, Ghana; October’08, L. Rivkin, PSI & EPFLSLAC Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL ACCELERATORS: INSTRUMENTS FOR

• High frontier

• High luminosity frontier

• High precision measurements

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Energy available in collisions (center-of-mass energy) E Fixed target geometry E  2mc2  E cm E Colliding beams

Ecm  2E

or for unequal Ecm  2 E1E2

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Livingston plot

Equivalent energy of a fixed target accelerator

E 2 E  cm 2mc 2 COLLIDER CIRCULAR

BECAME THE MOST POWERFUL ACCELERATOR FOR RESEARCH IN PARTICLE PHYSICS IP

IP COLLISION AT THE IP (Interaction Point) Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Luminosity

N 2  1  L  f A cm2  s

Interaction rate dn R   L  dt int Point cross-section

1   int s2

Unit: barn = 10 -24 cm2

1 pb

1 fb History of luminosity in the world

1034cm-2s-1=10 /nb/s Scaling of high energy proton rings

1 BT  m  pGeV  0.29979... c

,costs  E

LEP tunnel: 1 TeV per 1 Tesla

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Scaling of high energy rings

Electrons emit synchrotron radiation

E4 E4 cost  a    b Power   2  2

,costs  E2

Linear Colliders : costs  E

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Linear Colliders

damping ring rf power source e+ e-

main linac beam delivery

RF in 30 – 40 km RF out

E

particles “surf” the electromagnetic wave

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Tunnel implementations (laser straight)

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana;Central24 L. Rivkin, MDI PSI& Interaction & EPFL Region 1 professional lifespan!

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Beyound LHC? An 80 km tunnel?

Magnetic field Energy c.o.m.

8.3 Tesla 42 TeV

16 Tesla 80 TeV

20 Tesla 100 TeV

John Osborne (CERN), Caroline Waaijer (CERN) ’s (1954) Space-Based World Machine Cosmic accelerators

Constellation Pictor: Pictor A X-ray image X-ray jet originating near a giant black hole

800‘000 years

Chandra X-Ray Observatory Useful books and references

H. Wiedemann, Particle Accelerator Physics I and II Springer Study Edition, 2003 K. Wille, The physics of Particle Accelerators: An Introduction Oxford University Press, 2001 D. A. Edwards, M. J. Syphers, An Introduction to the Physics of High Energy Accelerators John Wiley & Sons, Inc. 1993 E.J.N. Wilson, An Introduction to Particle Accelerators Oxford University Press, 2001 A. W. Chao, M. Tigner, Handbook of Accelerator Physics and Engineering, World Scientific 1999

CERN Accelerator School (CAS) proceedings E. D. Courant and H. S. Snyder, Annals of Physics: 3, 1 - 48 (1958) M. Sands, SLAC-121

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL 24 Nobel Prizes in Physics that had direct contribution from accelerators

Year Name Accelerator-Science Contribution to - 1980 James W. Cronin and Cronin and Fitch concluded in 1964 that CP (charge- Winning Research Val L. Fitch parity) symmetry is violated in the decay of neutral K 1939 Ernest O. Lawrence Lawrence invented the cyclotron at the University of mesons based upon their experiments using the Californian at Berkeley in 1929 [12]. Brookhaven Alternating Gradient Synchrotron [28]. 1951 John D. Cockcroft and Cockcroft and Walton invented their eponymous linear 1981 Kai M. Siegbahn Siegbahn invented a weak-focusing principle for Ernest T.S. Walton positive-ion accelerator at the in betatrons in 1944 with which he made significant Cambridge, England, in 1932 [13]. improvements in high-resolution electron spectroscopy 1952 Bloch used a cyclotron at the Crocker Radiation [29]. Laboratory at the University of California at Berkeley 1983 William A. Fowler Fowler collaborated on and analyzed accelerator-based in his discovery of the magnetic moment of the neutron experiments in 1958 [30], which he used to support his in 1940 [14]. hypothesis on stellar-fusion processes in 1957 [31]. 1957 Tsung-Dao Lee and Chen Ning Lee and Yang analyzed data on K mesons (θ and τ) 1984 and Rubbia led a team of who observed the Yang from Bevatron experiments at the Lawrence Radiation intermediate vector bosons W and Z in 1983 using Laboratory in 1955 [15], which supported their idea in CERN’s proton-antiproton collider [32], and van der 1956 that parity is not conserved in weak interactions [16]. Meer developed much of the instrumentation needed 1959 Emilio G. Segrè and Segrè and Chamberlain discovered the antiproton in for these experiments [33]. 1955 using the Bevatron at the Lawrence Radiation 1986 Ruska built the first electron microscope in 1933 based Laboratory [17]. upon a magnetic optical system that provided large 1960 Donald A. Glaser Glaser tested his first experimental six-inch bubble magnification [34]. chamber in 1955 with high-energy protons produced by 1988 Leon M. Lederman, Lederman, Schwartz, and Steinberger discovered the the Brookhaven Cosmotron [18]. , and muon neutrino in 1962 using Brookhaven’s Alternating 1961 Hofstadter carried out electron- experiments Gradient Synchrotron [35]. on carbon-12 and oxygen-16 in 1959 using the SLAC 1989 Paul’s idea in the early 1950s of building ion traps linac and thereby made discoveries on the structure of grew out of accelerator physics [36]. nucleons [19]. 1990 Jerome I. Friedman, Friedman, Kendall, and Taylor’s experiments in 1974 1963 Goeppert Mayer analyzed experiments using neutron Henry W. Kendall, and on deep inelastic scattering of electrons on protons and beams produced by the Richard E. Taylor bound neutrons used the SLAC linac [37]. cyclotron in 1947 to measure the nuclear binding 1992 Charpak’s development of multiwire proportional energies of krypton and xenon [20], which led to her chambers in 1970 were made possible by accelerator- discoveries on high magic numbers in 1948 [21]. based testing at CERN [38]. 1967 Hans A. Bethe Bethe analyzed nuclear reactions involving accelerated 1995 Martin L. Perl Perl discovered the tau lepton in 1975 using Stanford’s protons and other nuclei whereby he discovered in SPEAR collider [39]. 1939 how energy is produced in stars [22]. 2004 David J. Gross, , Gross, Wilczek, and Politzer discovered asymptotic 1968 Luis W. Alvarez Alvarez discovered a large number of resonance states using his fifteen-inch hydrogen bubble chamber and and freedom in the theory of strong interactions in 1973 high-energy proton beams from the Bevatron at the H. David Politzer based upon results from the SLAC linac on electron- Lawrence Radiation Laboratory [23]. proton scattering [40]. 1976 and Richter discovered the J/ particle in 1974 using the 2008 Makoto Kobayashi and Kobayashi and Maskawa’s theory of quark mixing in Samuel C.C. Ting SPEAR collider at Stanford [24], and Ting discovered 1973 was confirmed by results from the KEKB the J/ particle independently in 1974 using the accelerator at KEK (High Energy Accelerator Research Brookhaven Alternating Gradient Synchrotron [25]. Organization) in Tsukuba, Ibaraki Prefecture, Japan, 1979 Sheldon L. Glashow, Glashow, Salam, and Weinberg cited experiments on and the PEP II (Positron Electron Project II) at SLAC , and the bombardment of nuclei with neutrinos at CERN in [41], which showed that quark mixing in the six-quark 1973 [26] as confirmation of their prediction of weak model is the dominant source of broken symmetry [42]. neutral currents [27].

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL 19 Nobels with X-rays

Chemistry Physics 1936: Peter Debye 1901 Wilhem Rontgen 1962: Max Purutz and Sir John 1914 Kendrew 1915 Sir William Bragg and son 1976 William Lipscomb 1917 Charles Barkla 1985 Herbert Hauptman and 1924 Karl Siegbahn Jerome Karle 1927 Arthur Compton 1988 Johann Deisenhofer, Robert 1981 Huber and Hartmut Michel 1997 Paul D. Boyer and John E. Medicine Walker 1946 Hermann Muller 2003 Peter Agre and Roderick Mackinnon 1962 Frances Crick, James Watson and Maurice Wilkins 2009 V. Ramakrishnan, Th. A. Steitz, A. E. Yonath 1979 Alan Cormack and Godfrey Hounsfield

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Light sources

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL 60‘000 users world-wide

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL The “brightness” of a light source:

Source area, S Angular Flux, F divergence, W

Brightness = constant x ______F S x W

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Steep rise in brightness the second wave SLS XFEL SOLEIL (F) DIAMOND (UK) 21 … 10 Undulators

ESRF

SPring8 1015 Wigglers APS

Bending Moore’s Law for magnets semiconductors 109 Rotating anode

1900 1950 2000 Bertha Roentgen’s hand (exposure: 20 min) The electron beam “emittance”:

Source area, S The brightness Angular depends on the divergence, W geometry of the source, i.e., on the electron beam emittance Emittance = S x W

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Medical applications

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Protons – treatment of tumors improved radiation therapy > 800 patients treated with deep-seated tumors > 5800 patients treated with eye tumors

> 50 % of patients are below 40 years old 7% 25% 14% <20 21-30 31-40 41-50 13% 51-60 12% 61-70 >70

14% 15% BRAGG PEAK

PROTO N BEAM … ALLOWS THE TREATMENT OF DEEP  INSIDE LYING TUMORS WITH BEST PROTECTION OF THE SURROUNDING

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Comparison of Characteristics

of Photons und Protons for Radiation Therapy

Dose

Tumor

Depth (cm)

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL

SPOT SCANNING

POSITION

ENERGY GANTRY

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Aim of proton therapy: Dose concentrated in the tumor volume, low dose or no dose to healthy tissues

Protons IMRT -Photons

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL First accelerators

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Electrostatic linear accelerator

COCKROFT WALTON VAN DE GRAFF TANDEM PELLETRON CATHODE

- U +

SLS DC electron gun: U = 90 kV, Ek = 90 keV

2 2 m v eU  E  m c (γ  1)  o non-relativistic approxim. k o 2

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL First accelerators: Cockcroft and Walton 1932

7Li  p    17.2 MeV

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Going beyond 1 MV

Can we repeat the process of DC acceleration?

Need time varying fields V t

V t t

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Wideroe Linac 1928   0.04 Acceleration of Ion source Drift tubes slow ions

Beam

RF Transmitter

fRF ~ 1–7 MHz

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL FOR THE SAME ENERGY EXTRACTED FROM THE FIELD, A PARTICLE WITH LOWER MASS IS MORE RELATIVISTIC

CATHODE

v U + c - 1 v 1 0.8   1  2 c  v/c 0.6 e p 0.4

eU 0.2   1  Eo 0

0.001 0.01 0.1 1 10 100 1000 10000 eU [MeV]

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL ALAVAREZ DTL

FERMILAB The drift tubes are enclosed in a single resonant tank in order to avoid large radiative energy losses at higher frequencies (e.g. 200 MHz)

ALVAREZ LINACS WORK UP TO  ~ 0.4

A NEW STRUCTURE IS REQUIRED FOR RELATIVISTIC PARTICLES !

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Electron RF linacs

Disk loaded accelerating structure slows down the RF wave to let electron keep up with it

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL SLS 100 MeV RF linac

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Lawrence: coiled up linac

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL First accelerators: cyclotron Livingston and Lawrence 4.5 inch model cyclotron 27 inch cyclotron

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL First accelerators: cyclotron

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Rolf Wideröe‘s notebook

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL Donald Kerst: first betatron (1940)

"Ausserordentlichhochgeschwindigkeitelektronenent wickelndenschwerarbeitsbeigollitron"

Introduction to Accelerators, African School of Physics, KNUST, Kumasi, Ghana; L. Rivkin, PSI & EPFL