Author: Miura, T.
Paper Title Page
TUCOYBS01
KEK ERL SRF Operation Experience  
 
  • H. Sakai, T. Furuya, E. Kako, T. Konomi, T. Miura, F. Qiu, K. Umemori
    KEK, Ibaraki, Japan
 
  We will present the SRF operation experience during long-term cERL operation in KEK.  
slides icon Slides TUCOYBS01 [8.289 MB]  
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TUCOZBS04 Characterization of Microphonics in the cERL Main Linac Superconducting Cavities 48
 
  • F. Qiu, D.A. Arakawa, M. Egi, E. Kako, H. Katagiri, T. Konomi, T. Matsumoto, S. Michizono, T. Miura, H. Sakai, K. Umemori
    KEK, Ibaraki, Japan
  • M. Egi, S. Michizono
    Sokendai - Hayama, Hayama, Japan
  • E. Kako, T. Konomi, T. Matsumoto, T. Miura, F. Qiu, H. Sakai, K. Umemori
    Sokendai, Ibaraki, Japan
 
  In the main linac (ML) of the KEK-cERL, two superconducting cavities with high loaded Q (QL ¿ 1×107) are operated in continuous wave (CW) mode. It is important to control and suppress the microphonics detuning owing to the low bandwidth of the cavities. We evaluated the background microphonics detuning by the low level radio frequency system during the beam operation. Interestingly, a ¿field level dependence microphonics¿ phenomenon was observed on one of the cavities in the ML. Several frequency components were suddenly excited if the cavity field is above a threshold field (~3 MV/m). We found that this threshold field is probably related with the cavity quench limits despite the unclear inherent physical mechanism. Furthermore, in order to optimize the cavity resonance control system for better microphonics rejection, we have measured the mechanical transfer function between the fast piezo tuner and cavity detuning. Finally, we validated this model by comparing the model response with actual system response.  
slides icon Slides TUCOZBS04 [7.564 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-ERL2019-TUCOZBS04  
About • paper received ※ 13 September 2019       paper accepted ※ 01 November 2019       issue date ※ 24 June 2020  
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