1. Study of Electromagnetic Interactions of Light Ions in the Framework of the IHEP Ion Program at U70 Serguei Sadovsky, IHEP, Protvino EMIN-2009, Moscow, 19 September 2009

2. Outlook IHEP accelerators Positroniy channel Possible physics domains Conception of experimental setup Conclusion

3. 23 декабря 2008Сессия-конф. СЯФ ОФН РАН3 IHEP accelerators U70 accelerator Linac U30 Buster U1.5 Linac I100

4. Linac for light ion acceleration: I100 p, d ion source 3 м TOF: ЦФ HV generator Up to +750 кV pN +, O + N 2 +,O 2 + 2008 N 2 +,O 2 + p d 100 ns 50 mА p 15 mА d 5 mks 16.7 MeV/n 2008

5. Light ion source: I100 (laser source of 12 C)‏ IHEP laser (CO 2, 2.7 J, 10  m, 0.25 Hz)‏ IGP of RAS laser (…, 10 Hz)‏ Beam of C 5+ 40 mA @ entry toI100 1.6 mA @ exit from I100

6. Light ions: channel from I100 to U1.5 17.11.06: p 72.7 MeV 01.12.06: d 16.7 MeV/n

7. Light ions: December 2008 d in U70 after 4 magnets 10–12.12.08; d; 16.7–> 455 MeV/n April 2009: d-beam circulation in U70

8. Ion beam extraction from U70 5 mm Si crystal station 1.7  10 13 proton p (U30) 3  10 9 carbon 12 C 6+ 1  10 11 deuteron d 2-9  10 11 proton p ( I100 ) N B0 Ions in U70

9. Proposal to study the ion beam extractions in «Positroniy» channel

10. Experimental area of «Positroniy» channel: two beam magnets and one of two secondary targets are proposed to install, the available Z distance is 15 m tg 1 tg 2 M1 M2

11. Up to 10 6 12 С/cicle in «Positroniy» channel is expected due to beam extraction with Si Crystal Extraction efficiency is 0.1% Crystal bended angle ~ 60 mrad 1.7  10 13 proton p 3  10 9 carbon 12 C 6+ 1  10 11 deuteron d 2-9  10 11 proton p N B0 Ions in U70 Extraction efficiency vs banded angle

12. Intensities of secondary radioactive beams in 12 С fragmentation The secondary beam optics allows to have beams of different radioactive nuclei At the intensity of 12 C primary beam I=3·10 9 /cycle the fragment intensities variate from I=10 6 /cycle for 8 Li and to I=10 4 /cycle for 8 He Important: the fragments have different rigidity => fragments identification with Spectroscopic magnet is possible

13. Physics case 1: study of light nuclei at the limit of neutron stability

14. Light nuclei beyond the neutron stability

15. PHYSICS case 2: Nuclear Clastering of the 12 С fragments, including short- leaved and exotics nuclei 9 Li 178 ms 8 Li 838 ms 6 He 807 ms 8 He 119 ms  can be studied at U70 P.Zarubin, JINR LINC-2008

16. Nuclear Clustering P.Zarubin, JINR LINC-2008  can be studied at U70

17. Angular distribution of fragments without spectroscopic magnet 16 O + p -> 4 He + X at 3.25 AGeV/c V.V.Glagolev at al. 2001 Θ(25AGeV) ~ Θ(3.25AGeV)*3.25/25 => R Fr > 1.7 cm at Z = 15 m

18. Excitation energy per nucleon, MeV T 10 9 K Liquid Gas PHYSICS case 3 : phase transition in a cold nuclear matter ?

19. PHYSICS case 4: neutral meson photoproduction in AA-collisions b) photoproduction Coherence condition in the inverse kinematics: -q 2 < 1/R target, i.e. E γ < γ/R target = γ/1.2A 1/3

20. Inverse kinematics of neutral meson photoproduction in the AA-collisions E γ (max) = γ/1.2A 1/3 for 12 C + 56 Fe -> meson+X =  and 25 AGeV/c 12 C beam E thr ~ E γ (max) ~ m meson γ = 26.6 E γ (max) = 1140 MeV Thus π 0, η, ω, φ photoproduction is possible in the reaction 12 C + 56 Fe -> meson+X at 25 AGeV/c The meson energy in the Lab frame is as follows: E meson > γ m meson, i.e. E(π) > 3.6 GeV E(η) > 14.6 GeV E(ω) > 20.8 GeV E(φ) > 27.1 GeV

21. TrigBm = S1*S2*E PB (E<E thr1 )*E PSD (E<E thr2 )‏ PSD LGD2 Magnet Plastic Ball target S2S1 MWPC6 MWPC4 MWPC3 MWPC2MWPC1 MWPC5 UrQMD simulation: C+C at 25A GeV/c, Total p z of beam fragments in lab TrigTg = S1*S2*E PB (E>E thr1 )*E PSD (E>E thr2 )‏ Setup conception for the light ion fragmentation studies in ion-ion EM-interaction Beam

22. WA98 plastic ball: fragment detection in the target reference frame

23. Projectile Spectator Detector (PSD@CBM) for detection of the beam fragmentation Spectator spots at Z=15m, E Au =15 AGeV, simulation Beam hole X Z Transverse sizes ~1x1 m 2 ; Distance from target - 15 m; Number of modules – 107; Module dimensions – 10x10x160 cm 3 A.P.Ivashkin 2008, INR RAN

24. PSD for CBM, design, construction and beam test results: Modular Lead/Scintillator sandwich compensating calorimeter Sampling ratio Pb:Scint=4:1 Expectation: For thickness δ Pb =16 mm and δ Scint =4 mm σ E /E ~ 50%/√E 60 lead/scintillator sandwiches. 10 longitudinal sections 6 WLS-fiber/MAPD MAPDs and amplifiers A.P.Ivashkin 2008, INR RAN measurements

25. Spectroscopic magnet in the experimental aria of the “Positroniy” channel (JINR)‏ and DC

26. Lead Glass Detector LGD2 (IHEP, Hyperon setup)‏

27. Conclusion Ion beams at U70 accelerator are expected for users in 2010-2011 The expected intensity of 12 C beam in “Positroniy” channel is up to 10 6 /cycle Different radioactive light ion beams can be created on the base of carbon beam with momentum of 25-30 AGeV/c An essential part of experimental equipment exists and could be used in the future experimental setup for 12 C+A interaction studies This opens several quite interesting physics domains for experimental studies, including light nuclei at the limit on neutron stability, EM fragmentation of light radioactive nuclei, phase transition in a cold nuclear matter and neutral meson photoproduction Welcome to participate in the experiment