Author:
Tamura Jun,Kondo Yasuhiro,Morishita Takatoshi,Naito Fujio,Otani Masashi,Nemoto Yasuo
Abstract
Abstract
In 2013, the Annular-ring Coupled Structure (ACS) cavities were installed to the Japan Proton Accelerator Research Complex (J-PARC) linac. Since then, the ACS cavities have been stably running. Although any serious problem induced by the RF window had not yet observed, we decided to replace the RF window of one ACS cavity by the newly manufactured one. The major motivations of the replacement are to check the surface condition of the RF window which have been under operation for nearly five years, to confirm that the new RF window fully meets specifications, and to learn how much time is required for high-power conditioning of the new RF window. By making use of the summer maintenance period of 2018, we carried out the replacement. This was the first experience for us to replace the RF window installed to the ACS cavity in the linac accelerator tunnel. As for the removed RF window, there was no any abnormal warning found with the visual examination. At the resuming of the cavity operation after the maintenance period, we conducted the high-power conditioning in a measured manner. It took around fifty hours so that the targeted peak power was stably input to the cavity through the new RF window. The ACS cavity with the new RF window is now stably operating.
Subject
General Physics and Astronomy
Reference6 articles.
1. First high-power model of the annular-ring coupled structure for use in the Japan Proton Accelerator Research Complex linac;Ao;Phys. Rev. ST Accel. Beams,2012
2. First annular-ring coupled structure cavity for the Japan Proton Accelerator Research Complex linac;Ao;Phys. Rev. ST Accel. Beams,15
3. Dielectric Constant Measurement using Resonant Frequencies for Minimizing the Reflection of Pillbox RF Windows;Ao
4. Impedance matching of pillbox-type RF windows and direct measurement of the ceramic relative dielectric constant;Ao;Nuclear Instruments and Methods in Physics Research A,2014
5. Low-Reflection RF Window for ACS Cavity in J-PARC Linac;Tamura