基于潘宁源的氢等离子体全局模型数值模拟分析OA

[Background]Penning ion sources are widely employed in small-scale accelerators owing to their structural simplicity,compact geometry,and low power consumption,yet the quantitative dependence of their discharge characteristics and hydrogen ion species distribution on operating parameters remains insufficiently understood.[Purpose]The present work systematically investigates the influence of operating parameters—working gas pressure,power,and magnetic field strength—on the plasma electron density and on the relative fractions of H+,H+2,and H+3ions.[Methods]Taking the collisional ionization ofH2molecules as the object of investigation,a global physical model of the Penning ion source was established that incorporates the principal electron-impact ionization,dissociation,and ion-molecule reactions occurring in the discharge.The working gas pressure was scanned from 6×10-4 Pa to 8×10-2 Pa,the input power from 1 W to 10 W,and the magnetic field strength from 0.005 T to 1 T,and the predictive reliability of the model was further validated by comparison with PIC/MCC simulations and diagnostic measurements reported in the literature.[Results]At a magnetic field of 0.5 T and an input power of 5 W,as the gas pressure increased from 6×10-4 Pa to 8×10-2 Pa,theH+2fraction decreased from approximately 85％to below 5％,while theH+3fraction rose from about 8％to over 90％,and theH+fraction remained below 7％throughout.At 5 W and 0.1 Pa,increasing the magnetic field from 0.005 T to 1 T raised theH+fraction from approximately 3.5％to about 10.7％,and the calculated trends agreed well with the reference simulations and measurements.[Conclusions]These results indicate that the proposed global model reliably reproduces the variation of plasma electron density and hydrogen ion species fractions with pressure,power,and magnetic field,which provides a useful theoretical reference for the optimization and design of Penning ion sources.