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Xu, Q. J.

Paper Title Page
MOPP044 Cavity Diagnostic System for the Vertical Test of the STF Baseline 9-cell Cavity at KEK 643
 
  • Y. Yamamoto, H. Hayano, E. Kako, S. Noguchi, M. Satoh, T. Shishido, K. Umemori, K. Watanabe
    KEK, Ibaraki
  • S.-I. Moon
    POSTECH, Pohang, Kyungbuk
  • H. Sakai, K. Shinoe
    ISSP/SRL, Chiba
  • Q. J. Xu
    IHEP Beijing, Beijing
 
  Four 9-cell cavities, which are TESLA-type 9-cell cavities, were developed and tested in KEK for the future ILC project. A simple cavity diagnostic system was introduced to search the heating spot and to detect the x-ray emission. It is composed of the carbon resistors and the PIN photo diodes. They were attached on the equator of the cell, around the HOM couplers and on the end flanges. They were very effective to search the heating spot and to detect the x-ray emission during the vertical tests. All cavities eventually had the heating spot around the equator in the final state of the vertical test. It is conceivable that the quality of the electron beam welding was somewhat poor, when the dumbbells were connected. On this February, a new vertical test facility will be completed in STF (Superconducting RF Test Facility). Six 9-cell cavities will be tested by using the new system for S0 plan, which goal is the higher accelerating gradient for ILC. The new temperature and x-ray mapping system and new DAQ system will be introduced. This paper reports the recent status in the new vertical test facility in KEK-STF.  
MOPP144 The First Cool-down Tests of the 6 Meter-Long-Cryomodules for Superconducting RF Test Facility (STF) at KEK 892
 
  • N. Ohuchi, F. Furuta, K. Hara, H. Hayano, N. Higashi, Y. Higashi, H. Hisamatsu, K. Hosoyama, E. Kako, Y. Kojima, M. Masuzawa, H. Matsumoto, H. Nakai, S. Noguchi, T. Saeki, K. Saito, T. Shishido, A. Terashima, N. Toge, K. Tsuchiya, K. Yokoya
    KEK, Ibaraki
  • M. H. Tsai
    NSRRC, Hsinchu
  • Q. J. Xu
    IHEP Beijing, Beijing
 
  KEK is presently constructing the Superconducting RF Test Facility (STF) as the center of the ILC-R&D in Asia from 2005. In this project, KEK aims to get the manufacturing and operational experiences of the RF cavity and cryomodule toward the ILC, and two cryomodules have been developed. These cryomodules are 6 meter long and have 4 nine-cell cavities in each cryostat. The basic cross section designs of the cryomodules are almost same as the design of TESLA type-III, however, each cryostat has the different type of cavities, TESLA type and Low-Loss type. The tests for the cryomodules are planed to be performed at three steps. In the first test, measurements of the cryogenic performances of these cryomodules are the main objective. One nine-cell cavity was assembled in each cryostat and the cool-down of the two cryomodules was performed. In the following tests, the four nine-cell cavities will be assembled in each cryostat as the complete integration and the beam test will be performed. In this paper, we will report the design of the cryomodules and the cryogenic performances at the first cold test.  
MOPP168 Tests on the 1.3 GHz Low Loss Single-Cell RF Superconducting Large Grain Cavities of IHEP 943
 
  • Z. G. Zong, J. Gao, M. Q. Ge, J. Gu, H. Sun, D. Wang, Q. J. Xu, J. Y. Zhai, F. C. Zhao
    IHEP Beijing, Beijing
  • F. Furuta, T. Saeki, K. Saito
    KEK, Ibaraki
  • L. Q. Liu
    Technical Institute of Physics and Chemistry, Beijing
  • L.-Y. Xiong, L. Zhang, T. X. Zhao, Z. G. Zong
    TIPC, BeiJing
 
  To contribute to the International Linear Collider (ILC) R&D on the 1.3 GHz low loss cavities has been carried out at IHEP since 2005. Six cavities had been fabricated by the standard technology and treated by some procedures of surface treatments, such as centrifugal barrel polishing, barrel chemical polishing, annealing, high pressure rinsing and baking at in-house IHEP. Because of the shortage of liquid helium in Beijing two large grain cavities with a fine grain one were sent to KEK for vertical tests. The large grain cavities was tested and treated at KEk and finally both reached the accelerating gradients of more than 35 MV/m with the maximum of 40.27 MV/m. This paper presents the testing and results of the large grain cavities.