Experimental study on the gas-stripping chamber of an E//B neutral particle analyzer  

作　　者：Long Ma De-Hao Xie Yan-Xi Wang Shuo Wang Ji-Feng Han Wei-Ping Lin Jian-Li Liu Xing-Quan Liu Yu-Guo Liu Xiao-Bing Luo Yuan Luo Guo-Feng Qu Yu-Fan Qu Pei-Pei Ren Roy Wada Lin-Ge Zang Jing-Jun Zhu 

机构地区：[1]Key Laboratory of Radiation Physics and Technology of the Ministry of Education,Institute of Nuclear Science and Technology,Sichuan University,Chengdu 610064,China [2]Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China [3]Southwestern Institute of Physics,Chengdu 610218,China [4]Cyclotron Institute,Texas A&M University,College Station,TX 77843,USA

出　　处：《Nuclear Science and Techniques》2024年第11期98-107,共10页核技术（英文）

基　　金：supported by the National MCF Energy R&D Program of China(MOST 2018YFE0310200);in part by the National Natural Science Foundation of China(Nos.11705242,11805138,12175156);in part by the Fundamental Research Funds for the Central Universities(Nos.YJ201820,YJ201954)in China.

摘　　要：Stripping units take a key role in the neutral particle analyzer(NPA).A renovated gas-stripping unit was constructed for the newly designed E//B NPA.Using H_(2)as the working gas,we measured the gas inlet pressure(P_(0))and vacuum chamber pressure(P_(3)).The pressure distribution inside the gas-stripping room was calculated with Ansys Fluent,using the measured P_(0)and P_(3)as boundary conditions.The stripping efficiency of the stripping unit was then simulated utilizing the Geant4 Monte Carlo code for the H and D particles.The pressure P_(0)=40 Pa,which is one-sixth of what found in the previous design and corresponds to a thickness of 1.27×10^(17)atoms∕cm^(2),was obtained as the optimum working pressure for the upgraded stripping unit.An 50 kV electron cyclotron resonance(ECR)ion source platform was designed and constructed for E//B NPA calibration,and its performance has been measured.Using the ECR ion source platform,we measured the efficiency of the stripping unit through an inverse experiment with proton beams.We compared the current ratios of measurements with and without H_(2)gas to Geant4 simulation results.We found adequate agreement between the overall trends of the experiment and the simulation.The significant deviation for incident energies below 20 keV may result from the scattering effects of low-energy protons,leading to reduced accuracy in single-scattering physics in Geant4 simulations.Applying the scattering corrections observed in the reverse experiments obtains more accurate stripping efficiencies for H and D atoms in the energy range of 20–200 keV and the global efficiency with the maximum values of 95.0%for H atoms and 78.9%for D atoms at 200 keV.

关 键 词：NPA Gas-stripping ECR ion source Stripping efficiency GEANT4 

分 类 号：TL631.24[核科学技术—核技术及应用]