Control of Beam Polarization at the NICA Collider A.M. Kondratenko 2, A.D. Kovalenko 1, M.A....

Control of Beam Polarization Control of Beam Polarization

at the NICA Colliderat the NICA Collider

A.M. Kondratenko2 , A.D. Kovalenko1, M.A. Kondratenko2 ,

Yu.N. Filatov1,3 and V.A. Mikhaylov1

1Join Institute for Nuclear Research, Dubna, Russia 2 Science and Technique Laboratory Zaryad, Novosibirsk, Russia

3Moscow 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

2A.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

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Solenoids with stationary fields of Bmax~1517 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=425 Tm (protons) (B||L)max=480 Tm (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


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Polarization control in the Collider by means of small longitudinal field integrals

Gy

is the spin rotation angle between the solenoids

y

yz

sin

)sin(21

yz

sin

sin22

is the orbit rotation angle between the solenoids is the angle between the polarization and velocity directions

21, zz are the spin rotation angles in the solenoids

B

LBG i

zi||1

zy eeS

cos sinSPD



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The scheme makes it possible: to provide polarization control of different particles (p,d,3He,…); 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




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5,3 5,3

Inserts for proton and deuteron

polarization control



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The optical transparency scheme of coupling compensation with a structural quadrupole


are angles between quadrupole normal and vertical accelerator axis 45i

is the structural defocusing quadrupoleG0 -2

0 m ,60k

LS, m L0, m L1, m L2, m L, m Ltot, m

0,40 0,40 0,30 0,30 0,10 3,8

B||L||,Tm B||, T k1, m-2 k2, m-2 G1, T/m G2, T/m

0,5 0,63 0,05 0,1 2,2 4,5

mT45 B

0GGi


xBG yi / is quadrupole gradient ][m,/ -2BGk ii is the spin rotation angle in solenoids

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The coupling compensation scheme for half Siberian Snake


are angles between quadrupole normal and vertical accelerator axis 21, xBG yi / is quadrupole gradient ][m,/ -2BGk ii

LS, m L1, m L2, m L, m 1 2

2,4 0,15 0,7 0,10 45 36

B||L||,Tm B||, T k1, m-2 k2, m-2 G1, T/m G2, T/m

protons 25 5,2 0,56 0,89 25 40

deuterons 80 16,6 1,1 1,4 48 63

mT45 B


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Conclusions



Schemes were developed for NICA thateliminate depolarization problem during accelerationallow control of the beam polarization with small fields without

orbit perturbationmake 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 schemesmake possible ultra-high precision experiments with polarized

beams

Thank you for your attention!

Control of Beam Polarization at the NICA Collider A.M. Kondratenko 2, A.D. Kovalenko 1, M.A....

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