发表机构
Tsinghua University（清华大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
清华大学为S3FEL研制了216.667 MHz连续波VHF电子枪，优化腔体实现29.9 MV/m阴极梯度和856 kV加速电压，暗电流仅6.8 nA，打破室温VHF枪电压纪录。
AI 中文摘要
清华大学为深圳超导软X射线自由电子激光（$\ m S^3FEL$）装置研制了一台工作于216.667 MHz谐振频率的甚高频（VHF）电子枪。在SHINE电子枪设计的基础上，对腔体轮廓进行了优化，以在相当的输入功率下获得更高的阴极电场梯度和更高的加速电压。改进后的腔体几何结构还改善了二次电子倍增性能。此外，进行了热分析以指导水冷设计，并在阴极附近实施了增强冷却。在高功率 conditioning 过程中，82 kW的连续波射频功率成功耦合进电子枪，对应阴极梯度为29.9 MV/m，加速电压为856 kV。该电子枪电压超过了此前室温VHF电子枪的世界纪录。用法拉第杯在电子枪出口测得的最大暗电流仅为6.8 nA。
英文摘要
A very-high-frequency (VHF) electron gun operating at a resonant frequency of 216.667 MHz has been developed at Tsinghua University for the Shenzhen Superconducting Soft X-ray Free-Electron Laser ($\rm S^3FEL$) facility. Building upon the SHINE gun design, the cavity profile was optimized to achieve a higher cathode electric-field gradient and a higher accelerating voltage at comparable input power. The revised cavity geometry also yields improved multipacting performance. In addition, thermal analysis was carried out to guide the water-cooling design, and enhanced cooling was implemented in the vicinity of the cathode. During high-power conditioning, 82 kW of continuous-wave radio-frequency power was successfully coupled into the gun, corresponding to a cathode gradient of 29.9 MV/m and an accelerating voltage of 856 kV. The gun voltage surpasses the previous world record for room-temperature VHF guns. The maximum dark current measured by the Faraday cup at the gun exit was only 6.8 nA.
