• C. Cheng, J.S. Duo, J. Lv, S.X. Zheng
  TUB, Beijing
• J. Li
  CAEP/IFP, Mainyang, Sichuan

Mini-LIA was a miniature linear induction accelerator designed and manufactured by China Academy of Engineering Physics and Tsinghua University. To investigate the higher order mode (HOM) of Mini-LIA cavity, especially the frequency and quality factor Q of the TM110 and TM120 in it, both numerical simulation and experiments were performed. Several models of the cavity were established and calculated by using E module of MAFIA code. Network analyzer was applied to measure the frequency and Q in cavity. Both the simulation results and the experiment results are presented in this paper. The results of the experiments were coincident with the calculated results. Finally, The HOM characteristic of Mini-LIA cavity with metglass core in it was explored, and some interesting results was obtained.

• Q.Z. Xing, T.T. Liang, J. Lv, D.C. Tong
  TUB, Beijing

The application of the genetic algorithm in the diagnosis of the coupled cavity chain is investigated in this paper. One program named GANL2 has already been developed based on the genetic algorithm at Tsinghua University. The cell frequencies, quality factors, and coupling between the cells can be estimated by GANL2 if the pass-band reflection curve is known. This method has been applied in the diagnosis of the S-band and X-band standing-wave linac cavities. In this paper we present the preliminary investigation of the genetic algorithm in the diagnosis of the L-band 9-cell superconducting copper cavity model. The result of the calculation and measurement are compared. Not all the cells are diagnosed well. More precise measurement is needed for further study.