摘要
脉冲展宽分幅相机是时间分辨率优于10 ps的二维超快诊断设备,但展宽脉冲沿阴极传输会引起阴极不同位置的电压分布出现差异,这会导致相机时间不均匀现象的产生,从而限制了大探测面相机的实现。采用雪崩三极管、雪崩二极管和高通滤波器设计了一种快斜率皮秒选通脉冲,基于电脉冲叠加原理,探讨了选通脉冲下降沿对时间不均匀性的提升效果。研究结果显示:当阴极电压为-2 kV、电子束初始时间宽度为5 ps和展宽斜率为11.9 V/ps时,随着展宽脉冲沿阴极起点传输到终点,阴极上的电子束展宽倍率由11.74增至39.04,基于相对误差原理,两者相差232.5%;当将选通脉冲下降沿和展宽脉冲同时加载至阴极时,电子束展宽倍率由11.28变化至14.23,两者相差下降至40.21%,此时脉冲展宽分幅相机的时间分辨均匀性得到了有效提升。
Objective The framing camera is a two-dimensional(2D)ultrafast diagnostic device with high spatio-temporal resolution.In inertial confinement fusion(ICF)experiments,it can effectively acquire the duration and dynamic images at the stage of implosion compression.The pulse dilation framing camera is a new ultrafast diagnostic device with temporal resolution better than 10 ps.Firstly,this paper loads the dilating pulse between the photocathode(PC)and grid to achieve greater acceleration energy of the front edge of electron beams.Then,the temporal width of the electron beam is dilated through long-distance transmission.Finally,the dilated electron beam signal is measured by the microchannel plate(MCP)framing camera,and the temporal resolution is exponentially improved.However,in the pulse-dilation framing camera,with the transmission of dilating pulse along the PC,the voltage at different positions on the PC is changed,which results in temporal non-uniformity.This is one of the main factors restricting the development of framing cameras with large detection areas.To improve the restriction of temporal non-uniformity of the pulse-dilation framing camera,the gating pulse with picoseconds is designed,and the improvement of the temporal uniformity is studied by simultaneously loading the falling edge of the gating pulse and dilating pulse on the PC,which is based on the variational phenomenon of voltage during the transmission of dilating pulse along the PC.Methods This paper first deduces the computational equation of the dynamic dilating ratio of the electron beam along the PC by analyzing the causes of temporal non-uniformity and combines the principle of temporal dilation and the transmission characteristics of the electric pulse along the PC.Then,the high-voltage gating pulse with picoseconds is designed by the three-stage Marx pulse generator and the pulse shaping circuit.The Marx pulse generator is realized by the series and parallel of avalanche triodes,and the pulse shaping circuit is made up of the avalanche di
作者
伍思其
白雁力
高海英
姚荣彬
刘达见
Wu Siqi;Bai Yanli;Gao Haiying;Yao Rongbin;Liu Dajian(School of Electronic Engineering and Automation,Guilin University of Electronic Technology,Guilin 541004,Guangxi,China;School of Information and Communication,Guilin University of Electronic Technology,Guilin 541004,Guangxi,China)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2023年第5期253-258,共6页
Acta Optica Sinica
基金
国家自然科学基金(11865007)
广西自然科学基金面上项目(2022GXNSFAA035561)
广西自动检测技术与仪器重点实验室主任基金(YQ22101)。
关键词
超快光学
超快诊断技术
脉冲展宽分幅相机
脉冲叠加技术
时间均匀性
ultrafast optics
ultrafast diagnosis technology
pulse-dilation framing camera
pulse superposition technique
temporal uniformity
