Author: Endo, K.
Paper Title Page
MOPMW010 Property Test of the Q-Factor for High Purity Copper at the Temperature of 20K 417
  • A. Iino
    Sokendai, Ibaraki, Japan
  • K. Endo
    TOYAMA Co., Ltd., Zama-shi, Kanagawa, Japan
  • S. Yamaguchi
    KEK, Ibaraki, Japan
  A coherent parametric x-ray radiation (PXR) source based on a cryogenic electron linac has been developed by Toyama Co., Ltd, KEK and Nihon University. This accelerator is a C-band normal-conducting compact linac that requires a high Q factor in the accelerating and de-celerating structures. To obtain a high Q factor, the ac-celerating and decelerating structures are operated around 20 K, and are joined by diffusion bonding and are constructed with high-purity 6N8 copper which has very low resistivity in extremely low temperatures. In this study, we report the measurements and calculation of the residual resistance ratio (RRR) for 6N8 copper and oxy-gen-free copper (Class 1) as well as the Q factor for a pillbox cavity made of 6N8 copper and Class 1. The results of a low-power test of this accelerating structure at low temperature are reported. The Q factor for a 6N8 copper pillbox cavity is not much higher than that of a Class 1 pillbox cavity at low temperatures Moreover, the Q factor is saturated when RRR is greater than 500.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW010  
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