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Yu.Shatunov Budker Institute of Nuclear Physics, Novosibirsk. Polarized beam studies at Budker Institute. SPIN2010 Julich. topics. • historical remarks • filtering theory • experiments with polarized target • radiative polarization
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Yu.Shatunov Budker Institute of Nuclear Physics, Novosibirsk Polarized beam studies at Budker Institute SPIN2010 Julich
topics •historical remarks • filtering theory • experiments with polarized target • radiative polarization • RF spin control and response functions formalism • spin flip with snake • absolute energy calibration at VEPP-4 and VEPP-2000 • conclusion
The method of filtering was proposed by P.L.Csonka, NIM 63 (1968) 247. Paris, Juelich and Nijmegen potential models give different results for and . Theory of pbar spin filtering TSR proton spin-filtering experiment (Heidelberg, 1993) The filtering method using a hydrogen gas target with the proton polarizationseems to be the most promising way to polarize stored antiprotons. Experimental test for pbar at AD is needed.
Experiments with Polarized Deuterium Target at VEPP-3 Atomic beam source I=8x1016 at/sec Superconducting magnet B=4.8 T VEPP-3 E=0.4-2 GeV Storage cell thickness = 0.8x1014at/cm2
Elastic deuteron formfactors e + d e + d pion photo-production γ + d d + π0 d (γ,pp)π- Expiments with internal polarized deuterium target at VEPP-3 Quasi-elastic proton knock-outd (e,e'p)n Details in talks of I.Rachek and V.Stibunov photo-disintegration γ+ d p + n
kinetic polarization (ring with one Siberian snake) Peq ≈ 80%by Radiative polarization (DK)
B=10 T Kinetic polarization (ASPIRRIN) SHR
The Novosibirsk super C-tau factory project β*=0.8 mm E=2-5 GeV L = 1035cm-2s-1 (crab-waist) e- polarized e+-?
Polarization scheme with 3 snakes (arc=1200+2 damping wigglers in the arc’s middle ) IP snake2 snake3 damping wiggler2 damping wiggler1 snake1
damping wiglers Super C-tau factory snakes (E=2.5 GeV)ASPIRRIN
5 snakes 3 snakes 1 snake Polarization degree
wk = (1+a) BVl wk = Bxl F3(θi) 4π B0 ρ 4π B0 ρ integer flat machine x RF dipole (x) RF solenoid Spin control by RF-fields z RF device y Fi – spin response functions Fi ~ dn/dxi |Fi(θ+2π)| = |Fi(θ)| Analysis of SPIn Resonance in RINg |F5| = |γdn/dγ| = |d| x
Adiabatic crossing:( 1) RF solienoid flipper!(VEPP-2M 1980) (g-2) e+ e- comparison , Spin resonance crossing similar to NMR 1960 Froissart-Stora: Single Resonance Model -resonance strength; - tuning - tuning rate • spin phase advance in • resonance zone
Spin2008 Anlysis of Data for Stored Polarized Beams Using a Spin Flipper Yu.Shatunov, S.Mane, V.Ptitsin
φ = π; z x y RF solenoid z RF dipole (Bz) x IUCF • detuned snake from 1/2IUCF, SHR, RHIC • circular RF fieldunpractical • mirror harmonic compensationRHIC? RF dipoles (Bx) 2 Snakes multi bunch ν = ½ slipping RF spin flip at machine with Siberian snake IUCF, AmPS, SHR RHIC
AC dipole DC spin rotator • AC dipole: • Bx field amplitude: 20 Gauss-m • frequency: • Spin rotator: • DC dipole magnet with vertical field • integrated field strength: 2.7 Tesla-m • dipole deflection: • 100 GeV: 8.2 mrad • 250 GeV: 3.2mrad (ν0+1) wk -167.493o 208.03o
ϴ1 ϴ2 rf2 rf1 no DC dipoles!
RF flipper |F3|
(damping time) spin tune spread Spin diffusion due to quantum fluctuations Quantum emission: in average=0 After average by synchrotron oscillations and for
1. Delay - function Energy shift due to synchronism with RF - amplitude of oscillation, - Floquet function, 2.magnetic field nonlinearities - chromaticity; Spin tune spread
Spin flip -1 1 -7.5 0 7.5 (kHz) Resonant depolarization 0 50 Hz -150 (VEPP-2M parameters) “Simulation” of RF spin control Assumptions: adiabatic resonance crossing ( ) and spin diffusion
s.c. s.c. depol. B-4 s.c. s.c. VEPP-3 (0.4-2 GeV) VEPP-4M (1-5 GeV) KEDR detector e+-e- collider VEPP-4 Precise J/ψfamily, D-mesons and τ-lepton mass measurements
Energy calibration at VEPP-4by resonant depolarization E=1548.55162 ±0.00032 MeV
e+-e- collider VEPP-2000 1. Precise measurement of the quantity R=(e+e-- > hadrons)/ (e+e-->+--) 2. Study of hadronic channels: e+e-- > 2h, 3h, 4h …, h= ,K, 3. Study of ‘excited’ vector mesons: , , , ,... 4. Study of nucleon-antinucleon pair production – nucleon electromagnetic form factors, search for NN-bar resonances, .. ILU CMD -3 3 MeV Linac 2.4 T dipole VEPP-2000 B -3M BEP 200 M eV –+ e,e synchro- SND booster betatron 900 M eV 13 T colenoid for FF + e+ convertor ♦ E 1 GeV(per beam) ♦ L 1×1032 cm-2 sec-1 (1×1 bunch) –
ζ ζ ζ 1.0 1.0 1.0 1.0 0.8 0.8 0.8 0.8 - + 0.6 0.6 0.6 0.6 0.4 0.4 0.4 0.4 - + 0.2 0.2 0.2 0.2 GeV GeV GeV GeV GeV GeV 0 0 0 0 0.4 0.4 0.4 0.4 0.4 0.4 0.6 0.6 0.6 0.6 0.6 0.6 1.0 1.0 1.0 1.0 1.0 1.0 0.8 0.8 0.8 0.8 0.8 0.8 τp τp τp τp 104 104 102 102 1 1 ζ ζ ζ ζ + - + - sec sec ζ 10-2 10-2 - + Radiative polarization at VEPP-2000(ASPIRRIN)
Resonant depolarization E = 750.67 ± 0.03 MeV E(MeV) 750.0 750.5 751.0 751.5
Summary • Theory opens way to polarized p-bar • Kinetic polarization has to work at future e+e- factories • Spin flipping technics has no misteries • ±2·10-7 energy calibration at VEPP-4 by resonant depolarization • VEPP-2000 started-up for e+e-→ hadrons measurements (0.4 – 2 GeV) • Radiative polarization at VEPP-2000