Parameter optimization for multi-dimensional laser cooling of an ion beam in the storage ring S-LSR

He, Z.*; Wei, J.*; Osaki, Kazuya*; Okamoto, Hiromi*; Noda, Akira*; Nakao, Masao*; Soda, Hikaru*; Yuri, Yosuke; Jimbo, Koichi*

The power of the cooling laser currently available in a compact ion cooler ring S-LSR, Kyoto University, is quite limited for generating ultralow-temperature ion beams. Therefore, parameters of laser cooling should be carefully determined in order to approach the lowest possible temperature in the experiment. This paper mainly concerns optimization of laser-cooling parameters and prediction of a possible lower limit of beam temperature in S-LSR, based on systematic molecular dynamics simulations. The adiabatic capture process of the ion beam was introduced to prevent the emittance from blowing up during bunching. The spot size of the laser was optimized with the total laser power limited. An optimum solenoid field strength was obtained for three-dimensional cooling. The lowest beam temperature achievable in S-LSR was predicted by choosing the parameters optimized.