Control of Beam Polarization at the NICA Collider A.M. Kondratenko 2, A.D. Kovalenko 1, M.A. Kondratenko 2, Yu.N. Filatov 1,3 and V.A. Mikhaylov 1 1 Join Institute for Nuclear Research, Dubna, Russia 2 Science and Technique Laboratory Zaryad, Novosibirsk, Russia 3 Moscow Institute of Physics and Technology, Dolgoprydny, Russia "ADVANCED STUDIES INSTITUTE – SYMMETRIES AND SPIN" (SPIN-PRAHA-2013 AND NICA-SPIN-2013) July 7 –13, 2013, Prague, Czech Republic

2 A.M.Kondratenko A.D.Kovalenko,Yu.N.Filatov, M.A.Kondratenko, V.A. Mikhaylov SPIN-Praha’2013, Prague, 7-13 July, 2013 Polarization control scheme in the Collider with spin tune = 0 If the two identical Siberian Snakes will be inserted in the opposite straight sections of the collider, then the spin tunes is equal to zero for any energies. Any arbitrary polarization direction of the particle is repeated after each turn. Thus, the possibility to stabilize any direction of the polarization at any point of the particle orbit by means of a small longitudinal field for different particle species is occurred. Blue arrows are the case of longitudinal polarization in SPD Red arrows are the case of vertical polarization in SPD Polarization in MPD in these cases is laying in the plane (zy) This case is analogues to the figure “8” shape collider in Jefferson Lab

3 Solenoids with stationary fields of B max ~1517 T can be used to obtain necessary integrals of longitudinal fields. Length of each solenoid can be limited to 4  5,5 m even in the case of deuterons. (B || L) max =425 Tm (protons) (B || L) max =480 Tm (deuterons) Solenoid-based Siberian Snake Polarization control scheme in the Collider with spin tune = 0 A.M.Kondratenko A.D.Kovalenko,Yu.N.Filatov, M.A.Kondratenko, V.A. Mikhaylov SPIN-Praha’2013, Prague, 7-13 July, 2013

4 Polarization control in the Collider by means of small longitudinal field integrals is the spin rotation angle between the solenoids is the orbit rotation angle between the solenoids is the angle between the polarization and velocity directions are the spin rotation angles in the solenoids A.M.Kondratenko A.D.Kovalenko,Yu.N.Filatov, M.A.Kondratenko, V.A. Mikhaylov SPIN-Praha’2013, Prague, 7-13 July, 2013

5 The scheme makes it possible:  to provide polarization control of different particles (p,d, 3 He,…);  to provide any direction of polarization in the particle orbit plane within the arcs (important for spin matching at injection, for polarimetry as well);  to provide any direction of polarization in the vertical plane (zy) in the both collider detectors;  realization of Spin Flipping System  to avoid the closed orbit local displacement Polarization control in the Collider by means of small longitudinal field integrals A.M.Kondratenko A.D.Kovalenko,Yu.N.Filatov, M.A.Kondratenko, V.A. Mikhaylov SPIN-Praha’2013, Prague, 7-13 July, 2013

6 Polarization control in the Collider by means of small longitudinal field integrals Inserts for proton and deuteron polarization control A.M.Kondratenko A.D.Kovalenko,Yu.N.Filatov, M.A.Kondratenko, V.A. Mikhaylov SPIN-Praha’2013, Prague, 7-13 July, 2013

7 Polarization control in the Collider by means of small longitudinal field integrals A.M.Kondratenko A.D.Kovalenko,Yu.N.Filatov, M.A.Kondratenko, V.A. Mikhaylov SPIN-Praha’2013, Prague, 7-13 July, 2013

8 The optical transparency scheme of coupling compensation with a structural quadrupole A.M.Kondratenko A.D.Kovalenko,Yu.N.Filatov, M.A.Kondratenko, V.A. Mikhaylov are angles between quadrupole normal and vertical accelerator axis is the structural defocusing quadrupole G0G0 L S, mL 0, mL 1, mL 2, m  L, m L tot, m 0,40 0,30 0,103,8 B || L ||,T  m B ||, Tk 1, m -2 k 2, m -2 G 1, T/mG 2, T/m 0,50,630,050,12,24,5 SPIN-Praha’2013, Prague, 7-13 July, 2013 is quadrupole gradient is the spin rotation angle in solenoids

9 The coupling compensation scheme for half Siberian Snake A.M.Kondratenko A.D.Kovalenko,Yu.N.Filatov, M.A.Kondratenko, V.A. Mikhaylov are angles between quadrupole normal and vertical accelerator axis is quadrupole gradient L S, mL 1, mL 2, m  L, m 11 22 2,40,150,70,10 4545 36  B || L ||,T  m B ||, Tk 1, m -2 k 2, m -2 G 1, T/mG 2, T/m protons255,20,560, deuterons8016,61,11,44863 SPIN-Praha’2013, Prague, 7-13 July, 2013

10 Conclusions A.M.Kondratenko A.D.Kovalenko,Yu.N.Filatov, M.A.Kondratenko, V.A. Mikhaylov SPIN-Praha’2013, Prague, 7-13 July, 2013 Schemes were developed for NICA that  eliminate depolarization problem during acceleration  allow control of the beam polarization with small fields without orbit perturbation  make it possible to efficiently control the polarization of a beam of particles with any anomalous magnetic moment including particles with small anomalous moments, such as deuterons  allow independent adjustment of polarization orientations in the two straights  allow single-turn as well as multi-turn spin-flipping schemes  make possible ultra-high precision experiments with polarized beams

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