High-repetition-rate sources of bright electron bunches have a wide range of applications. They can directly be employed as probes in electron-scattering setups, or serve as a backbone for the generation of radiation over a broad range of the electromagnetic spectrum. This paper describes the development of a compact sub-Mega-electronvolt (sub-MeV) electron-source setup capable of operating at MHz repetition rates and forming sub-picosecond electron bunches with transverse emittance below 20 nm. The setup relies on a conduction-cooled superconducting single-cell resonator with its geometry altered to enhance the field at the surface of the emitter. The system is designed to accommodate cooling using a 2 W pulse-tube cryogen-free cryocooler operated at 4.2 K. Although we focus on the case of a photoemitted electron bunch, the scheme could be adapted to other emission mechanisms.

高重复率的亮电子束源具有广泛的应用范围。它们可以直接用作电子散射装置中的探针，或者用作在宽泛的电磁频谱范围内生成辐射的主干。本文介绍了一种紧凑的亚兆电子（sub-MeV）电子源装置的开发，该装置能够以MHz重复频率工作，并形成横向发射低于20 nm的亚皮秒电子束。该设置依赖于传导冷却的超导单电池谐振器，其几何形状已更改以增强发射极表面的电场。该系统旨在使用在4.2 K下运行的2 W脉冲管无致冷剂的低温冷却器进行冷却。尽管我们专注于光发射电子束的情况，但该方案可适用于其他发射机制。