High Power THz Radiation From Electron Storage Ring By Means Of Beam Instability

研究了电子储存环NewSuBARU中高峰值电流束流产生的相干同步辐射(CSR)爆发的时间结构。这种CSR爆发的来源是由纵向束流不稳定性产生的束团中的精细时间结构。这种爆发是不稳定的，但非常容易获得，因此它可以用于一些实验应用中，适当的数据平均。在平均周期为10ms的情况下，积分功率的波动约为10%，这种波动与存储电流、动量压缩因子和射频加速电压有很小的依赖关系。而当射频相位调制为2fS(同步辐射振荡频率的两倍)时，脉冲串结构被调制为2fS，辐射功率的起伏在同步辐射振荡的时间尺度上减小。在环的多束团操作中，不同桶中的束团的爆发存在相关性，这是意想不到的。

The time structure of a burst of coherent synchrotron radiation (CSR) emitted from a high-peak-current beam in the electron storage ring NewSUBARU has been investigated. The source of this CSR burst is fine time structure in a bunch produced by longitudinal beam instability. This burst is unstable but very easy to obtain, so it can be used for some experimental applications with appropriate averaging of data. With an averaging period of 10 ms, the fluctuation of the integrated power was about 10%.This fluctuation had a small dependence on the stored current, momentum compaction factor, and the rf acceleration voltage. However when the rf phase was modulated with 2fs (twice of the synchrotron oscillation frequency), the burst structure was modulated with 2fs and the fluctuation of radiation power was reduces at time scale of the synchrotron oscillation. In multi-bunch operation of the ring, there was a correlation of the bursts from bunches in different bucket, which was not expected.