用于高平均功率自由电子激光器的DC–RF超导腔注入器

北京大学超导加速器实验室提出了新型DC?RF超导腔注入器的设计方案.该注入器由皮尔斯引出结构、1+1/2超导腔组成,可以提供高品质的、CW模式或高占空比(1%以上)的电子束.对该注入器进行了分析计算和设计研究,通过改变超导腔首腔腔形以增加聚焦效果,采取措施缩短阴极到超导腔的距离,从而有效地抑制束流发射度的增长.用PARMELA对该注入器进行束流动力学研究,以确定皮尔斯引出结构的形状以及超导腔的同步相位.计算结果表明这种用于高平均功率自由电子激光的注入器的设计方案是可行的.

Design of a New DC-RF Injector Used in High Average Power FEL

Here we give the design proposal of a new DC-RF injector used in high average power FEL. The injector includes a Pierce gun and a 1+1/2 SC cavity. It will be able to provide high average beam current because it can work in CW mode. By changing the shape of the first 1/2 cell of SC cavity to enforce the focusing effect, we can decrease the distance between photocathode and SC cavity. Thus, the growth of emittance can be suppressed effectively. Through the simulation of particle dynamics with PARMELA, the shape of Pierce gun and the optimized synchronous phase of the SC cavity can be decided. The simulation results show that this kind of injector is feasible.