同步触发和级联滤波的分幅相机皮秒高压脉冲研究

Picosecond high voltage pulse of framing camera with synchronous trigger and cascade filter

脉冲展宽分幅相机是脉冲展宽技术与微通道板(microchannel plate,MCP)分幅相机的结合体,其时间分辨率与皮秒高压脉冲呈非线性波动关系.采用同步触发模式和级联结构LC高通滤波器产生皮秒高压脉冲,将其与影响时间分辨率的阴极电压和漂移距离结合,应用于脉冲展宽分幅相机的时间分辨率研究中.结果表明,同步触发式多级Marx电路能产生半高宽优于1 ns的高压脉冲,随着级联LC高通滤波器从1阶增至7阶,产生皮秒高压脉冲的半高宽从558 ps降至409 ps,幅值从-3.6 kV降至-1.4 kV,上升沿斜率的非线性波动为5.03~10.25 V/ps;将其加载于MCP通道内的光电子倍增模型,获得的MCP分幅相机时间分辨率由206 ps提高至149 ps;而将其应用于脉冲展宽分幅相机,随着阴极电压和漂移距离增加,时间分辨率的非线性波动为3.8~39.4 ps.通过数据统计和对比发现,当同步触发Marx电路与3阶LC高通滤波电路相结合时,脉冲展宽分幅相机的时间分辨率能达到最优.

The pulse-dilation framing camera(PDFC)is a composite of pulse-dilation technique and microchannel plate(MCP)framing camera.Its temporal resolution is a nonlinearly fluctuated relation with picoseconds high voltage pulse(PHVP).The PHVP is generated using the model of synchronous triggering and the cascade structure of the LC high-pass filter,which is combined with the cathode voltage and the drift distance that affect temporal resolution,and is applied to the study of time resolution of PDFC.The research results show that the synchronous triggering Marx circuit can generate high voltage pulse with the full width at half maximum(FWHM)better than 1 ns,and when the LC high-pass filter is increased from the first order to the seventh order,FWHM of the PHVP is reduced from 558 ps to 409 ps,the amplitude is decreased from-3.6 kV to-1.4 kV,the slop of the rising edge is nonlinearly fluctuated in the range between 5.03 V/ps and 10.25 V/ps.The temporal resolution of the MCP framing camera is reduced from 206 ps to 149 ps by loading the PHVP on the model of photoelectron multiplication in the channel of the MCP;while the PDFC is loaded by the PHVP,the temporal resolution is nonlinearly fluctuated in the range between 3.8 ps and 39.4 ps by increasing the cathode potential,and drift distance.The temporal resolution of the pulse-dilation framing camera can be optimized by carrying the data statistics and comparisons,when the synchronous trigger Marx circuit is combined with the 3rd order LC high-pass filter circuit.