Photonuclear Laboratory

1. GSI – 13 March – 2004 ELISe collaborationPhotonuclear Reactions at Storage RingsV. NedorezovInstitute for Nuclear Research RAS, Moscow, 117312www.inr.ras.ruPhotonuclear Laboratory

2. Photonuclear Laboratory • Institute for Nuclear Research RAS, Moscow • Synchrotron 35 MeV – 1947 • Synchrotron 250 MeV – 1960 • Linac 100 MeV - 1970 • Microtron 175 MeV - under manufacturing • Kurchatov Institute, Moscow • KSRS 2.5 GeV - since 2000 • M.V.Lomonosov Moscow State University • Microtron 80 MeV – since 2001 • Photonuclear reactions at low and intermediate energies • Electron scattering • Photo and electro - fission • Current International collaborations: • A2 – Mainz - Experiments with real photons • DELTA-SIGMA - Dubna - Spin effects in NN scattering • GRAAL – Grenoble - Photoproduction of heavy mesons • XI Int. Seminar “Electromagnetic interactions of Nuclei at • Low and Medium Energies” is scheduled for 2006.

3. V.G.Nedorezov, A.A.Turinge, Yu.M.Shatunov • «Photonuclear Experiments with Back Scattered Gamma Beams». • UFN 47 , 4, 341-358 [2004]

4. Compton Beam Installations

5. Virtual photons Electron Scattering • Electromagnetic form-factor: • ds/dW =ds/dW Mottx [(F1 gN )2 +t (F2 gN )2 + 2t ( F1 gN +F1 gN )2 tan2 (q/2)] • t = Q2 /4MN2 , • F1,2 g,p = 2/3 F1,2 u - 1/3 F1,2 d - 1/3 F1,2 s , • F1,2 gN = 2/3 F1,2 d - 1/3 F1,2 u - 1/3 F1,2 s

6. Physics features

7. Experimental features • Internal target • Backgrounds Bremsstrahlung – Luminosity monitor

8. Photon beam parameters

9. Compton Scattering Amplitude and dispersion relations: • f = e’*e f1(w) + i w s e’* xe f2(w) • e – EM field operator, • s - Spin operator (nucleon). • If w = 0 (low energy thorem): • f1(0) = - (a / Z2 / M ), f2(0) = (ak 2 / 2M 2 ), • M – mass, a = e2 /4p = 1/137 • eZ – charge, • k - anomalous magnetic moment of nucleon • f1(0) = - (a / Z2 / M ) + w2/2p2stot(w’)/f(w’) dw’ • f2(0) = (a k 2 / 2M 2 ) + w2/2p2Dstot(w’)/f(w’) dw’/w’ • stot(w) = s3/2(w) + s1/2(w), • Dstot(w) = s3/2(w) - s1/2(w), • Sum rule GDH : • Y = (s3/2(w) + s1/2(w)) dw/w= 2p2ak2/M2

10. Compton Back Scattering Method Laser (hw = 2.34 эВ) Gamma beam Electron beam Е = 140 МeVЕ = 2.5 GeV Be Mirror Intensity (gammas/s): Argon (UV) 107 СО2 (IR) 1010 FEL 1012 Recirculation 1015

11. Basic relations n = qg, g = Ee/me, l = 2gw /Ee, K = 1 + n + l , x = {x1 , x2 , x3 ), x = 2pk/m2 , y = 2pk’/m2. • , f –emission angle; к,k’и p,p’ - initial and final momentum of photon and electron x = {x1 , x2 , x3 ) – Stock’s parameters

12. Gamma beam parameters Circular polarization Energy Spectrum Linear polarization

13. ConclusionReal and virtual gamma beams • High intensity Compton and Bremsstrahlung beams • Coulomb dissociation of Heavy Ions • Electron scattering. E- HI colliders