Author: Chen, J.
Paper Title Page
MOA1I3 Intense Beam Issues in CSNS Accelerator Beam Commissioning 16
 
  • L. Huang, H.Y. Liu, X.H. Lu, X.B. Luo, J. Peng, L. Rao
    IHEP CSNS, Guangdong Province, People’s Republic of China
  • Y.W. An, J. Chen, M.Y. Huang, Y. Li, Z.P. Li, S. Wang
    IHEP, Beijing, People’s Republic of China
  • S.Y. Xu
    DNSC, Dongguan, People’s Republic of China
 
  The China Spallation Neutron Source (CSNS) consists of an 80 MeV H⁻ Linac, a 1.6 GeV Rapid Cycling Synchrotron (RCS), beam transport lines, a target station, and three spectrometers. The CSNS design beam power is 100 kW, with the capability to upgrade to 500 kW. In August 2018, CSNS was officially opened to domestic and international users. By February 2020, the beam power had reached 100 kW, and through improvements such as adding harmonic cavities, the beam power was increased to 140 kW. During the beam commissioning process, the beam loss caused by space charge effects was the most significant factor limiting the increase in beam power. Additionally, unexpected collective effects were observed, including coherent oscillations of the bunches, after the beam power reached 50 kW. Through a series of measures, the space charge effects and collective instabilities causing beam loss were effectively controlled. This paper mainly introduces the strong beam effects discovered during the beam commissioning at CSNS and their suppression methods. It also briefly discusses the research on beam space charge effects and collective effects in the beam dynamics design of CSNS-II project.  
slides icon Slides MOA1I3 [8.597 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-HB2023-MOA1I3  
About • Received ※ 01 October 2023 — Revised ※ 05 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 24 October 2023
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THBP53 Commissioning and Operation of the Collimation System at the RCS of CSNS 615
 
  • S.Y. Xu, J. Chen, S. Wang
    IHEP, Beijing, People’s Republic of China
  • K. Zhou
    IHEP CSNS, Guangdong Province, People’s Republic of China
 
  For high-intensity proton synchrotrons, minimizing particle losses during machine operation is essential to avoid radiation damage. Uncontrolled beam loss posed a significant challenge to achieving higher beam intensity and power for high-intensity proton synchrotrons. The beam collimation system can remove halo particles and to localize the beam loss. The use of collimation system is an important means of controlling uncontrolled beam loss in high-power proton accelerators. To reduce the uncontrolled beam loss, a transverse collimation system was designed for the RCS of CSNS. The design transverse collimator is a two-stage collimator. During the beam commissioning of CSNS, the designed two-stage collimator has been changed to one-stage collimator to overcome the problem of low collimation efficiency caused by insufficient phase shift between the primary and secondary collimators. By optimizing the collimation system, the beam loss is well localized in the collimator area, effectively reducing uncontrolled beam loss. The beam power of CSNS achieved the design value of 100 kW with small uncontrolled beam loss.  
poster icon Poster THBP53 [0.780 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP53  
About • Received ※ 30 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 10 October 2023
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