Author: Chen, Q.
Paper Title Page
THPO028 Magnetic Field Measurement and Analysis for Drift Tube Linac of CSNS 738
 
  • B. Li, M.X. Fan, A.H. Li, P.H. Qu, Y. Wang, X.L. Wu
    CSNS, Guangdong Province, People’s Republic of China
  • Q. Chen, K.Y. Gong, W. Kang, H.C. Liu, J.X. Zhou
    IHEP, Beijing, People’s Republic of China
 
  Funding: The National Natural Science Foundation of China(11105166); Youth Innovation Promotion Association(2015011)
A 324MHz Alvarez-type Drift Tube Linac (DTL) is used to accelerate the H ion beam from 3 to 80 MeV with peak current 15mA for China Spallation Neutron Source (CSNS). DTL is composed by 36 meters cavity and 161 DTs, the DT magnet coil adopted SAKAE structure with compact, smaller aperture. Magnetic field is measured by self-developed high precision rotating coil measurement system. This paper introduces the rotating coil measure-ment system simply and presents the 161 DTs magnetic field measurement results comprehensively, include mag-netic field center offset, integral magnetic field, higher-order harmonics. In addition, cooling test result of magnet coil is also presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO028  
About • paper received ※ 31 August 2018      issue date ※ 18 January 2019  
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THPO029 Quality Factor and Power Loss of the CSNS DTL 741
 
  • P.H. Qu, M.X. Fan, A.H. Li, B. Li, J. Peng, Y. Wang, X.L. Wu
    CSNS, Guangdong Province, People’s Republic of China
  • Q. Chen, K.Y. Gong, H.C. Liu
    IHEP, Beijing, People’s Republic of China
 
  An Alvarez-type Drift tube linac (DTL) was utilized to accelerate the H ion beam of up to 15mA peak current from 3 to 80MeV of China Spallation neutron source (CSNS). For ease of manufacturing and measurement, the CSNS DTL was divided into four independent cavities. The Q factor of four cavities were given, including the measurement results of low-power[1] and high-power[2], and several reasons for the low Q factor of the cavity in the measurement process were analysed. During the op-eration of the DTL, the frequent alarm of the water flow switch causes the power of the cavity to fall to 0. Esti-mate the power loss of each component, under the cir-cumstances of ensuring adequate water flow, reduce the alarm threshold of the water flow switch of some compo-nents to improve the stability of the system.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO029  
About • paper received ※ 22 August 2018      issue date ※ 18 January 2019  
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THPO030 Operation Experience of the CSNS DTL 744
 
  • H.C. Liu, Q. Chen, S. Fu, K.Y. Gong
    IHEP, Beijing, People’s Republic of China
  • M.X. Fan, A.H. Li, B. Li, J. Peng, P.H. Qu, Y. Wang, X.L. Wu
    CSNS, Guangdong Province, People’s Republic of China
 
  The China Spallation Neutron Source (CSNS) Drift tube linac (DTL) accelerates H beam from 3 to 80MeV with 4 independent tanks. The 80MeV beam acceleration was achieved in January 2018. The linac is a key to the reliability of the whole CSNS facility since all the beams stop when these upstream facilities fail. Many efforts have been made for DTL reliable operation. This paper presents the operation experience learned in DTL com-missioning.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO030  
About • paper received ※ 28 August 2018      issue date ※ 18 January 2019  
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THPO031 RF Conditioning and Beam Commissioning Status of CSNS DTL 747
 
  • Y. Wang, M.X. Fan, A.H. Li, B. Li, J. Peng, P.H. Qu, X.L. Wu
    CSNS, Guangdong Province, People’s Republic of China
  • Q. Chen, K.Y. Gong, H.C. Liu
    IHEP, Beijing, People’s Republic of China
 
  The high power RF conditioning of CSNS DTL was finished in April 2017 with peak input power 1.6MW, 650us pulse width, 25Hz repetition frequency. With careful tuning of RF amplitude and phase, beam was accelerated to 80MeV successfully with maximum peak beam current 12mA and about 98% transmission efficiency. DTL operate stably at full power level with several trips per day without beam interruption after six months commissioning. The whole RF conditioning process was presented and some details of beam commissioning were described in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO031  
About • paper received ※ 05 September 2018      issue date ※ 18 January 2019  
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THPO038 Status of the Power Couplers for the CSNS DTL 767
 
  • M.X. Fan, A.H. Li, B. Li, P.H. Qu, Y. Wang, X.L. Wu
    CSNS, Guangdong Province, People’s Republic of China
  • Q. Chen, K.Y. Gong, H.C. Liu
    IHEP, Beijing, People’s Republic of China
 
  There are four Drift Tube Linac (DTL) tanks in China Spallation Neutron Source (CSNS) Project. Each DTL tank requires a power coupler with a peak power of 2 MW and a duty cycle of 1.5% for beam operation. After approximately two years machining, all four couplers were already installed in the tunnel before year 2017. Up to now, the first phase of beam tuning has been completed, the maximum transmission power of the coupler exceeds 1.7 MW with a pulse width of 650 μs and a repetition rate of 25 Hz, meanwhile, the vacuum is maintained on the order of 10-6 Pa during the operation and no breakdown was observed. This paper describes the architecture, the fabrication, the low power test results and the high power conditioning process of the coupler. Some problems encountered are also presented.
This work was supported by Youth Innovation Promotion Association of CAS (2015011)
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO038  
About • paper received ※ 30 August 2018      issue date ※ 18 January 2019  
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