论文标题
高亮度光注射器中的单射击横向动量成像
Single shot cathode transverse momentum imaging in high brightness photoinjectors
论文作者
论文摘要
在最先进的光注射器电子来源，光发射的热发射占据了最终喷射器的发射。因此，低热发射阴极的开发和诊断非常重要。高梯度枪的常规热发射率测量值是耗时的，因此在光电阴极寿命期间，热发射率的测量不如量子效率那样频繁，尽管这两者都是Photojextor优化的重要特性。在本文中，建议对光电极激光斑点尺寸进行光发射横向动量的单个射击测量，即光电电极RF枪。通过调整枪支螺线管的聚焦，将阴极处的电子横向动量成像到下游屏幕，从而使RMS值和光电子横向动量的详细光谱单一的镜头测量。报告了原理实验的模拟和证明。
In state of the art photoinjector electron sources, thermal emittance from photoemission dominates the final injector emittance. Therefore, low thermal emittance cathode developments and diagnostics are very important. Conventional thermal emittance measurements for the high gradient gun are time-consuming and thus thermal emittance is not measured as frequently as quantum efficiency during the lifetime of photocathodes, although both are important properties for the photoinjector optimizations. In this paper, a single shot measurement of photoemission transverse momentum, i.e., thermal emittance per rms laser spot size, is proposed for photocathode RF guns. By tuning the gun solenoid focusing, the electrons transverse momenta at the cathode are imaged to a downstream screen, which enables a single shot measurement of both the rms value and the detailed spectra of the photoelectrons transverse momenta. Both simulations and proof of principle experiments are reported.
