Enhancing Temporal Uniformity in Pulse-Dilation Framing Camera Using Curved-Dilation-Pulse
Wenlong Lv, Yanli Bai, Yi Jiang, Guochun Huang, Songchun Li, Haoming Shuai, Dajian Liu · IEEE Transactions on Nuclear Science · 2025
The pulse-dilation framing camera (PDFC) is a two-dimensional ultrafast diagnostic device with high temporal resolution. In high-energy physics experiments, it can be used to investigate related transient processes and ultrafast dynamics. Nevertheless, the transmission of linear dilation pulse (DP) along photocathode (PC) may lead to temporal resolution non-uniformity in the PDFC, causing variations in the physical information captured at different time points and potentially resulting in distorted observations. To address issue, a curved dilation pulse (CDP) was designed using IGBT, transformer coils, and high-pass filters, and its application in improving temporal uniformity (TU) was investigated. The research findings indicate that the IGBT circuit can generate a CDP with non-linearly rising amplitude and a slope ranging from 0.132 to 3.39 V/ps. Under conditions of -3 kV PC voltage, an initial time width of 10 ps for the electron beam (EB), and a drift distance of 500 mm, when applied to an 80 mm long PC, the average relative error of EB dilation ratio (DR) along PC can be minimized to 0.63% (EBDR: 11.68× to 11.81×). This represents a significant enhancement in TU compared to the 7.20% (3.84× to 4.42×) achieved with the linear ones. Furthermore, when evaluated based on the maximum relative error of EBDR along PC, the CDP achieves 1.11%, compared with the multigroup high-precision time synchronization requirements of multipulse fusion (MPF, 9.14%, 9.52× to 10.39×) and V-shaped pulse superposition (VSPS, 26.15%, 11.28× to 14.23×), the CDP based on IGBT technology only requires a single group of time synchronization to effectively enhance TU. Meanwhile, the CDP can also be applied to one-dimensional streak camera for mitigating dynamic spatio-temporal distortion.