Speaker
Description
The EIC's Hadron Storage Ring will capture and accelerate spin-polarized hadron bunches from the injector chain comprising OPPIS/EBIS, Linac, Booster, and the AGS. If unaccounted for, polarized species will cross a vast number of depolarizing first-order spin-orbit resonances, which for ultra-relativistic particles occur every 523 MeV for protons, every 13.1 GeV for deuterons, every 336 MeV for helions, etc. Pairs of Siberian snakes, consisting of helical dipole magnets, are used to fix the closed-orbit spin tune at 1/2, thereby avoiding first-order spin-orbit resonances. Nevertheless, prominent higher-order spin resonances do arise in the vicinity of the strongest first-order resonances, and necessitate the use of multiple pairs of snakes for mitigation. The HSR is approximately three-fold super-periodic, and for such a ring we find that 12 snakes is a sufficient number for precisely cancelling first-order spin-orbit coupling independently of orbital tunes, using only these snakes. This number is too large, however, and we investigate how a smaller number of snakes can be optimally chosen by varying the betatron phase advance between the snakes to find an accelerator lattice configuration with the highest polarization transmission.
