电子束时间聚焦技术

利用时间展宽分幅相机研究电子束的时间聚焦现象.当阴极未加载脉冲电压时，测得相机的时间分辨率为80 ps.当阴极加载斜率为14 V/ps的脉冲电压、电路延时为11.395 ns时，相机的时间分辨率为8.8 ps，电子束的时间宽度经历了被压缩到被展宽的过程.改变阴极脉冲下降沿斜率，研究电子束时间聚焦时系统时间分辨与下降沿斜率的关系.当下降沿斜率为1 V/ps时，时间分辨近似等于80 ps，电子束到达微通道板时其时间宽度约等于原始宽度.当斜率大于1 V/ps时，时间分辨小于80 ps，到达微通道板时电子束时间宽度被展宽.当斜率为0.5 V/ps时，时间分辨大于80 ps，到达微通道板时电子束时间宽度被压缩.

Abstract

The time focus of electron pulse was studied by using the time dilation framing camera. While the PhotoCathode (PC) is not pulsed, the measured temporal resolution of the camera is 80 ps. While the pulse with a 14 V/ps gradient is applied on the PC, and the delay time of the circuit is 11.395 ns, the temporal resolution is 8.8 ps. The results show that the the temporal shape of the electron signal is compressed first and then dilated. Furthermore, the relationship between the temporal resolution and the falling edge gradient of the PC pulse is obtained. While the falling edge gradient of the PC pulse is 1 V/ps, the temporal resolution is about 80 ps. It shows that the time width of the electron pulse is approximately equal to its original width while the electrons arrive at the microchannel plate (MCP). While the gradient is more than 1 V/ps, the temporal resolution is less than 80 ps. The time width of the electron pulse is dilated while it arrive at the MCP. While the gradient is 0.5 V/ps, the temporal resolution is more than 80 ps. The time width of the electron pulse is compressed.

参考文献

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蔡厚智, 龙井华, 刘进元, 谢维信, 白雁力, 雷云飞. 电子束时间聚焦技术[J]. 光子学报, 2016, 45(2): 0204001. CAI Houzhi, LONG Jinghua, LIU Jinyuan, XIE Weixin, BAI Yanli, LEI Yunfei. Time Focus Technology for the Electron Bunch[J]. ACTA PHOTONICA SINICA, 2016, 45(2): 0204001.

电子束时间聚焦技术

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