A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

Higashi Y.

PaperTitlePage
TUP10High Reliable Surface Treatment Recipe of High Gradient Single Cell SRF Cavities at KEK125
 
  • F. Furuta, K. Saito, T. Saeki, H. Inoue, Y. Morozumi, Y. Higashi, T. Higo
    KEK
 
 We have continued the series tests of single cell superconducting cavities at KEK. These tests are aimed at establishing a high yield production of surface treatment that would reliably allow cavities to reach gradients in excess of 45 MV/m with high Q in vertical tests. The cavity shape is all of the KEK Low Loss design. Early results from this series test demonstrated that reaching gradients as high as 50 MV/m was feasible. However, the initial yield was of order 50 %. In order to increase the yield we have modified our surface preparation followed an established KEK procedure (KEK-WG5 recipe). We have succeeded to reach the >95 % yield with gradient of > 45 MV/m. 
WEP45The first processing of capacitive-coupling coupler at room temperature in a cryomodule at STF587
 
  • T. Saeki, H. Matsumoto, S. Kazakov, F. Furuta, K. Saito, Y. Higashi, T. Higo, H. Inoue, Y. Morozumi, M. Sato, H. Yamaoka
    KEK
  • J. Hong
    PAL
  • J. Zhai
    IHEP, CAS
 
 We are constructing Superconducting RF Test Facility (STF) at KEK for the R&D of ILC accelerator. In the beginning of year 2007, we installed one TESLA-like 9- cell cavity and one high-gradient Low-Loss (LL) type 9- cell cavity into cryomodules at STF. For the LL 9-cell cavity, an Capacitive-Coupling (CC) input-coupler, a ballscrew tuner and other peripherals were assembled with the cavity. The assembled cavity package was installed with thermal shields and so on into a cryomodule. After the installation, we performed the first processing of Capacitive-Coupling (CC) input-coupler in a cryomodule at the room-temperature. We achieved the power of 250 kW with the pulse-width of 1.5 msec at the repetition rate of 5 pps. This presentation describes about the assembly of a CC coupler and a high-gradient LL 9-cell cavity in a clean room and the processing of the CC coupler at the room temperature in a cryomodule.