Author: Honma, T.
Paper Title Page
TUPGW036 1 mA Stable Energy Recovery Beam Operation with Small Beam Emittance 1482
 
  • T. Obina, D.A. Arakawa, M. Egi, T. Furuya, K. Haga, K. Harada, T. Honda, Y. Honda, T. Honma, E. Kako, R. Kato, H. Kawata, Y. Kobayashi, Y. Kojima, T. Konomi, H. Matsumura, T. Miura, T. Miyajima, S. Nagahashi, H. Nakai, N. Nakamura, K. Nakanishi, K.N. Nigorikawa, T. Nogami, F. Qiu, H. Sagehashi, H. Sakai, S. Sakanaka, M. Shimada, M. Tadano, T. Takahashi, R. Takai, O. A. Tanaka, Y. Tanimoto, T. Uchiyama, K. Umemori, M. Yamamoto
    KEK, Ibaraki, Japan
  • R. Hajima, R. Nagai, M. Sawamura
    QST, Tokai, Japan
  • N. Nishimori
    National Institutes for Quantum and Radiological Science and Technology (QST), Sayo-cho, Japan
 
  A compact energy-recovery linac (cERL) have been operating since 2013 at KEK to develop critical components for ERL facility. Details of design, construction and the result of initial commissioning are already reported*. This paper will describe the details of further improvements and researches to achieve higher averaged beam current of 1 mA with continuous-wave (CW) beam pattern. At first, to keep the small beam emittance produced by 500 kV DC-photocathode gun, tuning of low-energy beam transport is essential. Also, we found some components degrades the beam quality, i.e., a non-metallic mirror which disturbed the beam orbit. Other important aspects are the measurement and mitigation of the beam losses. Combination of beam collimator and tuning of the beam optics can improve the beam halo enough to operate with 1 mA stably. The cERL has been operated with beam energy at 20 MeV or 17.5 MeV and with beam rep-rate of 1300 MHz or 162.5 MHz depending on the purpose of experiments. In each operation, the efficiency of the energy recovery was confirmed to be better than 99.9 %.
* S. Sakanaka, et.al., Nucl. Instr. and Meth. A 877 (2017)197, https://doi.org/10.1016/j.nima.2017.08.051
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW036  
About • paper received ※ 14 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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