Polarization transmission to high energy at the EIC's HSR

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. Due to their larger anomalous g-factor, polarized helions will undergo more frequent and stronger spin resonances than polarized protons in the HSR, in a regime not yet tested by RHIC since they are not yet available. We investigate two different snake-matching scenarios for the HSR by varying the betatron phase advance between the snakes to find an accelerator lattice configuration with the highest polarization transmission.