To meet requirements of high performance THz-FEL (Free Electron Laser), a compact scheme of FEL injector was proposed. Thermionic cathode was chosen to emit electrons instead of photo-cathode with complex structure and high cost. The effective bunch charge was improved to ~200pC by adopting enhanced EC-ITC (External Cathode Independently Tunable Cells) RF gun to extract micro-bunches, and back bombardment effects were almost eliminated as well. Constant gradient accelerator structures were designed to improve energy to ~14MeV, while focusing system was applied for emittance suppressing and bunch state maintenance. Physical design and beam dynamics of key components for FEL injector were analyzed. Furthermore, start-to-end simulations with multi-pulses were performed by using homemade MATLAB and Parmela. The results show that continual high brightness electron bunches with low energy spread and emittance could be obtained stably.
@article{arxiv.1306.0109,
title = {Physical design of FEL injector based on performance-enhanced EC-ITC RF gun},
author = {Tong-ning Hu and Qu-shan Chen and Yuan-ji Pei and Ji Li and Bin Qin},
journal= {arXiv preprint arXiv:1306.0109},
year = {2015}
}
Comments
6 pages, 13 figures; accepted by Chinese Physics C