Compensation of the Effect of the Imperfection of the Nuclotron/JINR Lattice on the Proton Polarization near an Integer Spin Resonance (Brief Review)

A number of open questions remain in the manipulation of the spins of colliding beams, which is a key aspect in the operation of polarized beam colliders such as the Nuclotron-based ion collider facility (JINR, Dubna, Russia) and the electron ion collider (BNL, United States). The spin transparency regime, which is the only realistic regime to control the deuteron polarization, has not yet been approved experimentally. With the existing configuration of the JINR accelerator complex, a pilot spin transparency experiment could be performed on a proton beam in the Nuclotron synchrotron. The dynamics of the proton beam polarization during the fast crossing of spin resonance guided by spin navigators based on regular orbit-steerer dipoles has been analyzed in this work. A scheme has been designed to compensate the coherent action of Nuclotron lattice imperfections on spin. In this scheme, the spin field induced by lattice imperfections is determined from the adiabatic deviation of spins in the resonance region, taking into account the synchrotron energy modulation. Integer-resonance strengths can be compensated down to the limits conditioned by orbital beam emittances. The numerical simulation of the proposed spin compensator has confirmed that the spin transparency regime in an imperfect Nuclotron lattice with a strongly distorted closed orbit can be experimentally verified.