FEL光学速调管的升级性能分析

通过三维磁场的有限元计算，给出了自由电子激光（FEL）研究用光学速调管升级后的磁参数。国家同步辐射实验室合肥光源（HLS）电子储存环能量可以日常运行在200～800 MeV间，为了与电子储存环能量匹配，并在较高束电子能量下进行实验和得到较多的相干辐射光子，光学速调管从原来的对称结构升级成非对称结构，用于HLS储存环谐波产生FEL实验。给出了升级后非对称光学速调管的几组匹配磁参数，用于在HLS储存环注入能量和可以运行的最高能量下进行谐波FEL实验。初步计算表明，HLS 储存环电子束性能优越，能散很低，FEL实验用最高能散仅为2.05×10-4，相应FEL辐射的能散修正因子在0.96以上，可以忽略不计。

Performance analysis of upgrading optical klystron for FEL

The parameters of an upgraded optical klystron (OK) were given by 3-dimensional finite element electromagnetic computation for free electron laser (FEL) research in Hefei electron storage ring. The Hefei Light Source (HLS) is routinely operated at 800 MeV by ramping up the injected 200 MeV electron beam. In order to match the routine operated energy of HLS and get more FEL photos, the symmetry OK is being upgraded to asymmetry structure for harmonic generation (HG) FEL experiments. Several HG FEL experimental groups of matched parameters of the upgraded OK were listed at the HLS injected energy as well as the maximum experimental energy. Primary computation shows that the energy spread of HLS in FEL experiments is below 2.05 × 10-4 , the correction factor due to it for FEL radiation is over 0.96, which can be nearly neglected.