Accelerator-physics Mas Master ter Aca Acade demy 2 my 201 018 - PowerPoint PPT Presentation

Introduction to Accelerators and Accelerator-physics Mas Master ter Aca Acade demy 2 my 201 018 8 Kur urt A t Aulen ulenba bache her Institut fü Institut für K r Ker ernp nphys hysik ik Joh ohan anne nes s Gute Gutenb nber erg g – Univ Univer ersität sität Main Mainz

I.1.0 Program This morning: Introduction to accelerators This afternoon: Introduction to Accelerator physics This afternoon: 15:00 guided tour through the MAMI accelerator K. Aulenbacher Master-Academy 2

I.1.0 Literatur Internet: Unterlagen der CERN Accelerator Schools (CAS) zu allgemeinen und speziellen Themen der Beschleunigerphysik unter http://cas.web.cern.ch/cas/ bzw. der U.S. Particle Accelerator School (USPAS) unter http://uspas.fnal.gov/ The Infancy of Particle Accelerators - Life and Work of Rolf Wideröe Compiled and edited by Pedro Waloschek http://www-library.desy.de/elbooks/wideroe/WiE-BOOK.htm und zur Vertiefung….. Berichte der „großen“ Beschleunigerphysik Konferenzen (seit 1965): http://accelconf.web.cern.ch/accelconf/ A.W. Chao, Physics of Collective Beam Instabilities in High Energy Accelerators, Wiley and Sons (download unter: http://www.slac.stanford.edu/~achao/wileybook.html) K. Aulenbacher Master-Academy 3

I.1.1 Definitions Concept of acclerators/accelerator physics Particle- Beam formation Accelerator source Experi ment (externer Beam) Experi ment (internal beam exp.) K. Aulenbacher Master-Academy 4

I.1.1 Definitions Particles: In Accelerators generated formed accleratec. stored: Elektronen (e - ), Protons (p), Ions (e.g. 12 C 1+ , 179 Au 79+ , 238 U 92+ ) Positrons (e + ), Anti-Protons (p) Muons ( m + , m - ) Neutrons (n) Molekules (z.B. LiH 2 - ) Created by accelerators and then used for experiments und dann ggf. manipuliert: Muons-, Pions- Neutrons short lived /exotic Isotops ( 6,8 He, 11 Li, 100 Sn) Superheavy nuclei ( 269 Ds – Darmstadium 110, 272 Rg – Röntgenium 111, Ununoctium - 118) Neutrinos Anti-Hydrogen Photons K. Aulenbacher Master-Academy 5

I.1.1 Definitions accelerator: Beam preparation/formatin and increase of kinetic energy (accleration) (but also de-acceleration for instance for trapping exotic particles, e.g. anti-hydrogen) Beamparameter: time structure dc (direct current = ) Frequency f (typ. MHz – GHz) cw (continous wave = ) Pulslength d t (typ. ps – m s) Micro-Pulslänge d t (typ. ps – m s, runter bis zu fs) pulsed ( Macro + Micro) Macro-Pulslänge D t (typ ns – ms) Frequenz f (typ. Hz – kHz) internal (‚trapped‘)  external Beam duty cycle = D t × f (Tast-Verhältnis) K. Aulenbacher Master-Academy 6

I.1.1 Definition Intensity: particle number n / Charge Q / Beam current I I = Q/t = n*q / t e.g.. cw-Beam with f=2.45GHz, d t=1.4ps, 255000 e - / Bunch (MAMI) → average current I = 2.45GHz*255000*1.602 · 10 -19 C / 1s = 100 m A → Peak-current Î = 255.000*1.602 · 10 -19 C / 1.4ps = 30mA average currents in accelerators pA bis A Peak-currents ~kA z.B 5kA = 3.1·10 9 e - in 100fs (XFEL, DESY) Beam dimensions: Transerse size + transverse momenta = Phase space („emittance) Paricel density in phase space = „Brightness“ ) K. Aulenbacher Master-Academy 7

I.1 Definitionen Energie / Impuls: Unit of energy : 1eV = kinetic energy of particle with charge e after falling through potetial of 1V in vacuum = 1.602·10 -19 J X ( t , x , y , z )  m P ( E , p , p , p )  m x y z   0 0      2     2 2 2 (Skalarpro dukt) E m c p c 0 1 0 0   X X    0   0 0 1 0 m m        0 0    2 2   E mc m c (Aus Lorentztra fo) 0 (Lorentz-Transformation   in z-Richtung)       2 2 E E m c 1 m c kin 0 0                p m v m c m c oder auch E 0 0 c mit : m : Ruhemasse 0 v 1 1          1  2   c 2 1 Masseeinheit: eV/c 2 (oft wg. Normierung c=1 auch nur eV) Impulseinheit: eV/c (oft wg. Normierung c=1 auch nur eV) K. Aulenbacher Master-Academy 8

I.1.1 Definition Storage ring: (Large) trap for charged particles with high kinetic energies ) E.g. Electrons: E=105GeV ( LEP / Perimeter 27km, CERN bis 2000)  = 105GeV / 511keV = 205500 /  =0.999999999988 4 x 8.7·10 11 e - correspond to 58.5kJ stored Energy Für Protonen: E=7TeV (im LHC / perimeter 27km, CERN ab 07/2008)  = 7TeV / 938.3MeV = 7460 /  =0.9999999910 Für 2808 x 1.15·10 11 p ents 362.1MJ gespeicherte Energie other Parameter: Spin / Polarisation ionic states Stability of current, position angle, energy Positions- / Winkelstabilitäten (sub m m Auflösung) Energiestabilität (z.B. MAMI 1keV bei 855MeV) K. Aulenbacher Master-Academy 9

I.2 Accelerators in fundamental research Mikroskopy to uncover small structures l: Wellenlänge size d Resolution of structure d requires l < d (Licht: Wellenlänge = 400 – 700nm ~ m m) K. Aulenbacher Master-Academy 10

I.2 h de Broglie relation l  h = 6.626·10 -34 Js = 4.136 ·10 -21 MeV/s (Matter/wave duality) p 7.7MeV 4 He: p =  /c E = 0.064 / c · (7.7MeV+3755.5MeV) = 240.8 MeV/c → l = 5·10 -15 m 1GeV 4 He: p =  /c E = 0.613 / c · (1000MeV+3755.5MeV) = 2917.4 MeV/c → l = 4·10 -16 m Structur size momentum Elektron-energy, kinetic Atom 10 -10 m 12.4keV/c 150,4eV Atomkern 10 -14 m 124MeV/c 123,5MeV Hadronen (p,n) 10 -15 m 1240MeV/c 1239,5MeV Hochenergie- physik 10 -18 m ~TeV/c ~TeV String Theorie 10 -33 m ~ 10 15 TeV/c ~ 10 15 TeV K. Aulenbacher Master-Academy 11

nuclei, e.g. Helium: Proton (1919) & Neutron (1931) (Nukleons) n p p n Elektron (1898) Proton: 10 -15 m, Ladung e + e Neutron: 10 -15 m, „neutral“ (point like,  E>300 MeV charge – e) ….but… K. Aulenbacher Master-Academy 12

K. Aulenbacher Master-Academy 13

Leptonen Quarks 1 e u d Elektron n e 12 5 ~ 0 ? 1 up down 2 Masse c n m Müon s m ~ 0 ? 215 210 2.500 strange charm 3 t n t b t Tau ~ 0 ? 3.500 8.300 340.000 bottom top 1 e - 1/3 e - Ladung 0 2/3 e + 4 Kräfte: Gravitation, Elektromagnetismus, Schwache Kraft, Starke Kraft Photon (  ) Z 0 , W ± (8x) QED QCD K. Aulenbacher Master-Academy 14

Hadronen Baryonen Mesonen Neutron Proton Pion u u d d u u d d m=938,3MeV m=939,6MeV m=139,6MeV m u =3MeV m d =6MeV ? ? ? many open questions ? ? ? Confinement ? Why 3 hierarchy ? ? ? ? ? ? ? ? Higgs mass 120GeV) K. Aulenbacher Master-Academy 15

Der Large Hadron Collider, CERN Proton – Proton Collider mit 2 · 7.000.000.000.000eV = 14TeV Energie p p LHC K. Aulenbacher Master-Academy 16

K. Aulenbacher Master-Academy 17

Large Hadron Collider, CERN Operational since: 2007 630MJ stored energy (~1000 PKW mit 100km/h) 1200 superconducting magnets 8,3T Data rate: 22000 DVD / s Darin ca. ein wichtiges Ereignis ! Internationales Projekt: K. Aulenbacher Master-Academy 18

Why operate ‚small‘ accelerators like the Mainzer Mikrotron MAMI ? K. Aulenbacher Master-Academy 19

Hadronen Collider are „Nucleon - smashers“ u u u u d d K. Aulenbacher Master-Academy 20

MAMI serves as a „precision tool“ point like Electron e e Nukleons are many body structures (Valence- quarks, Gluons, „Sea - Quarks“ generated by very complex „strong“ interaction K. Aulenbacher Master-Academy 21

Purpose of MAMI Coincidence experiments with c.w. beam to give optimum conditions for data acquisation. K. Aulenbacher Master-Academy 22

„Drei Spektrometer Anlage“ K. Aulenbacher Master-Academy 23

z.B. Charge distribution in Neutron Older prediction Recent Measurement at MAMI  Experimental tests for deeper understanding of strong interaction K. Aulenbacher Master-Academy 24

Nukleon (Proton, Neutron) ~ 10 -15 m ? 2 1 E out , p out , S out E in , p in , S in 3 Beam: E=1508MeV ± 0.030MeV (0.002%) E i , p i , S i I= ~ pA – 100 m A direction and position stable ~ 10 m m and murad ? If 1 + 2 + 3 are known, then may be determined! Coincidence-Experiments need cw-beams ! K. Aulenbacher Master-Academy 25

d.c. voltages: Van de Graaff 10.000.000V (1931) Source Vacuum Band- Generator d.c. beam e.g. a -particles v = 10,3%•c Target K. Aulenbacher Master-Academy 26

6.000.000V = 6MV Van de Graaff of HMI Berlin K. Aulenbacher Master-Academy 27

1924 Idea: Gustav Ising 1927 proof of principle: Rolf Wideröe (Aachen) Drifttube linear acclerator with „ac“ fields Source of Sodium +25.000eV Ions -25.000V K. Aulenbacher Master-Academy 28

Driftröhren-Linearbeschleuniger mit Wechselfeldern Quelle für +25.000eV Natrium Ionen +25.000eV -25.000V K. Aulenbacher Master-Academy 29

Driftröhren-Linearbeschleuniger mit Wechselfeldern =50.000eV Quelle für +25.000eV Natrium Ionen +25.000eV -25.000V K. Aulenbacher Master-Academy 30

Modern realisation for fast particles: Microwaves and resonator chains („cavities“) 25.000 W RF-power K. Aulenbacher Master-Academy 31

K. Aulenbacher Master-Academy 32

surf K. Aulenbacher Master-Academy 33

surf K. Aulenbacher Master-Academy 34

surfin’ on the wave K. Aulenbacher Master-Academy 35