At the electron linac for beams with high brilliance and low emittance (ELBE) center for high-power radiation sources, the second version of a superconducting radio-frequency (SRF) photoinjector has been put into operation and has been routinely applied for user operation at the ELBE electron accelerator. SRF guns are suitable for generating a continuous wave electron beam with high average currents and high beam brightness. The SRF gun at ELBE has the goal to generate short electron pulses with bunch charges of 200–300 pC at typical repetition rates of 100 kHz for the production of superradiant, coherent terahertz radiation. The SRF gun includes a 3.5-cell, 1.3-GHz niobium cavity and a superconducting solenoid. A support system with liquid nitrogen (${\mathrm{LN}}_2$) cooling allows the operation of normal-conducting, high quantum efficiency photocathodes. We present the design and performance of the SRF gun as well as beam measurement results of the operation with Mg photocathodes at an acceleration gradient of $8\mathrm{MV}/\mathrm{m}$ (4 MeV kinetic energy). In the last section, we discuss the SRF gun application for production of coherent terahertz radiation at the ELBE facility.

中文翻译：

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具有镁阴极的超导射频光电子枪在用户中的成功使用

在用于高功率辐射源的高亮度和低发射率电子束的线性加速器（ELBE）上，第二版超导射频（SRF）光电注入器已经投入运行，并已常规用于用户在ELBE电子加速器。SRF喷枪适合于产生具有高平均电流和高束亮度的连续波电子束。ELBE的SRF喷枪的目标是产生短的电子脉冲，其束电荷为200–300 pC，典型重复频率为100 kHz，用于产生超辐射相干太赫兹辐射。SRF喷枪包括一个3.5单元，1.3 GHz铌腔和一个超导螺线管。液氮支撑系统（${\mathrm{LN}}_{\mathrm{2个}}$）冷却使普通导电，高量子效率的光电阴极能够运行。我们介绍了SRF喷枪的设计和性能，以及在Mg光电阴极的加速度梯度为0的操作下的光束测量结果。$8\mathrm{MV}/\mathrm{米}$（4 MeV动能）。在最后一部分中，我们讨论了SRF喷枪在ELBE设施中用于产生相干太赫兹辐射的应用。