Tsinghua University has designed an X-band (11.424 GHz) slow-wave parallel-coupling accelerating structure, and demonstrated the high performance of the over-coupled structure operating with ultrashort pulse. In this study, we redesigned a 40-ns structure with 10 cells, tailored to the specifications of a high-power experimental platform, and provided a detailed analysis of the experimental results. Unexpected bead-pull results were observed during the cold testing, which we attribute to inter-cavity coupling. To explain these results, a multi-cell coupling circuit model was proposed and analyzed. High-power testing was conducted on the TPOT-X platform, and the highest gradient achieved was 130 MV/m after 1.1∗107 conditioning pulses. Compared to conventional multi-cavity high-gradient structures, the distributed power feeding system offers a shorter conditioning period and demonstrates the potential to achieve higher accelerating gradients under short-pulse operation.
@article{arxiv.2501.02780,
title = {Design, fabrication and test of parallel-coupled slow-wave high-gradient structure for ultrashort input power pulses},
author = {Weihang Gu and Hao Zha and Jiaru Shi and Yuliang Jiang and Jiayang Liu and Xiancai Lin and Focheng Liu and Huaibi Chen},
journal= {arXiv preprint arXiv:2501.02780},
year = {2025}
}