微波零相位法测量超导加速器ps级电子束纵向长度

Measurement of Picosecond Electron Beam Length with RF Zero-phasing Method

摘要: 本文基于微波零相位法，将中国工程物理研究院太赫兹自由电子激光(CTFEL)2×4-cell超导加速器的下游腔作为零相位腔，测量了上游腔增能后的电子束纵向长度，并通过束流动力学模拟证明,当两个超导腔正常工作时，上游腔出口处的电子束纵向长度与下游腔出口处的接近。实验结果表明，CTFEL 2×4-cell超导加速器能实现半高宽小于6.8 ps的电子束，满足装置出光要求。

Abstract: In this paper, the electron beam length of China Academy of Engineering Physics THz Free Electron Laser (CTFEL) was measured by the means of the RF zero-phasing method. The downstream cavity of the 2×4-cell superconducting accelerator was used as the zero-phasing cavity. Then the electron beam length accelerated by the first superconducting cavity was measured, which was proved to be almost the same as the one at downstream cavity when the two cavities were both working, by the means of dynamics simulation. The measurement results show that the FWHM of electron beam is less than 6.8 ps after the acceleration of the 2×4-cell superconducting accelerator, which meets the requirement of the facility.