In this Letter, we report the latest breakthroughs achieved with a direct-current (DC) and SRF combined photocathode gun at Peking University. We will first present a brief overview of the design considerations and main features. Then we will show the commissioning results.

2015年10月21日 · To obtain low-emittance electron beams with high average current, superconducting radio frequency photocathode guns have been developed by several laboratories worldwide. A DC-SRF injector, which combines a DC pierce gun and a superconducting cavity, has been developed at Peking University.

2020年11月16日 · dc-dc功率电感的选择要考虑电感值、内阻、饱和电流和尺寸等因素。 电感值应适中，内阻要小以降低转换效率损失和温度升高，饱和电流应足够大以减少饱和风险，尺寸则需平衡性能和产品体积需求。

The DC-SRF photocathode gun, an important member of superconducting radio-frequency (SRF) guns, is a distinguished compact mega-electron-volt (MeV) electron source capable of generating picosecond to sub-picosecond electron pulses at megahertz (MHz) and higher repetition rate.

Reducing the high di/dt loop area – integrated input capacitance. Reducing the high dv/dt node area – integrated L and smaller switch node. The SRF of the inductor can affect the L-C filter performance at high frequency. May be better to choose …

设计简单的 DCDC电路 时，初步计算后就可以根据电感直流电阻（DCR）、电容额定纹波电流和ESR这些都是首先关注的参数开始选型。 同样的，在 RF LNA电路 中，首先关心的是RF choke的Q值，叠层磁珠的Q值过低不宜使用已是共识。 但是感容元件的自谐振频率（Self-Resonant Frequency）这个"一说就会"的参数却很容易被新手忽视。 在MHz的DCDC和RF LNA电路中，被动元件自谐振频率是需要得到适当关注的。 C0G/NP0类的低损耗电容和高Q值RF绕线电 …

A hybrid SRF gun combining a direct-current (DC) gap and an SRF cavity, originally proposed by Peking University in 2001 The photocathode, located in the DC gap, is separated from the SRF cavity

2022年2月23日 · 2021 年，第二代 DC-SRF 光阴极注入器成功实现重复频率为 1 MHz 的连续波（CW）模式运行，并首次获得亚微米级归一化发射度的电子束。 北京大学物理学院副教授，重离子物理研究所副所长，中国粒子加速器学会理事。 本科就读于北京大学技术物理系原子核物理专业，硕士、博士就读于北京大学物理学院核技术及应用专业。 2005-2007、2008、2012年美国Duke大学物理系访问学者，从事储存环FEL研究。 2014年美国SLAC国家加速器实验室访问 …

As a compact photocathode injector with medium beam current, DC-SRF injector, which combines a DC pierce gun and a superconducting cavity, was first proposed by Peking University in 2001 [1]. A prototype of this kind of injector with 1.5-cell superconducting cavity was designed and constructed in 2004 [2].

The photocathode has been operated in the DC-SRF gun, and worked reliably in the cryogenic environment. The QE of the photocathode is stabilized at around 0.6% after inserted into the gun.