Abstract:
Booster ring of the high intensity heavy-ion accelerator facility is designed to increase the ion beam intensity up to its maximum limit and boost beam energy. However accumulated intensive beam induces depressed tune spread and shift by space charge effect and overlapping with low-order resonance stop-bands, which leads to emittance growth and even serious beam loss. In order to counteract the impact upon the circulating ion beam by low-order resonances, multipole magnetic field was introduced into the booster ring for compensating the six low-order resonances. Low-order resonances near working point of the booster ring and contributions to their stop-bands were discussed in this paper. Scheme on each stop-band compensation was also presented and further verified by numerical simulation. The results show that enhanced resonances caused by sextuple field for chromaticity correction in booster ring can be eliminated by compensation sextuple fields. This work will help to implement intensive heavy ion beam at the booster ring.