中国物理B ›› 2009, Vol. 18 ›› Issue (9): 3870-3876.doi: 10.1088/1674-1056/18/9/042

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Monte Carlo simulation of electron beam air plasma characteristics

韩先伟1, 谭畅1, 邓永锋2   

  1. (1)Shaanxi Power Machine Design and Research Institute, Xi'an 710100, China; (2)Shaanxi Power Machine Design and Research Institute, Xi'an 710100, China;State Key Laboratory of Materials Modification By Laser, Ion and Electron Beams, Department of Physics, Dalian University of Technology, Dalian 116085, China
  • 收稿日期:2008-09-27 修回日期:2009-04-10 出版日期:2009-09-20 发布日期:2009-09-20

Monte Carlo simulation of electron beam air plasma characteristics

Deng Yong-Feng(邓永锋)a)b)†, Han Xian-Wei(韩先伟)a), and Tan Chang(谭畅)a)   

  1. a Shaanxi Power Machine Design and Research Institute, Xi'an 710100, China; b State Key Laboratory of Materials Modification By Laser, Ion and Electron Beams, Department of Physics, Dalian University of Technology, Dalian 116085, China
  • Received:2008-09-27 Revised:2009-04-10 Online:2009-09-20 Published:2009-09-20

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摘要： A high-energy electron beam generator is used to generate a plasma in atmosphere. Based on a Monte Carlo toolkit named GEANT4, a model including complete physics processes is established to simulate the passage of the electron beam in air. Based on the model, the characteristics of the electron beam air plasma are calculated. The energy distribution of beam electrons (BEs) indicates that high-energy electrons almost reside in the centre region of the beam, but low-energy electrons always live in the fringe area. The energy deposition is calculated in two cases, i.e., with and without secondary electrons (SEs). Analysis indicates that the energy deposition of SEs accounts for a large part of the total energy deposition. The results of the energy spectrum show that the electrons in the inlet layer of the low-pressure chamber (LPC) are monoenergetic, but the energy spectrum of the electrons in the outlet layer is not pure. The SEs are largely generated at the outlet of the LPC. Moreover, both the energy distribution of BEs and the magnitude of the density of SEs are closely related to the pressure of LPC. Thus, a conclusion is drawn that a low magnitude of LPC pressure is helpful for reducing the energy loss in the LPC and also useful for greatly increasing the secondary electron density in dense air.

Abstract: A high-energy electron beam generator is used to generate a plasma in atmosphere. Based on a Monte Carlo toolkit named GEANT4, a model including complete physics processes is established to simulate the passage of the electron beam in air. Based on the model, the characteristics of the electron beam air plasma are calculated. The energy distribution of beam electrons (BEs) indicates that high-energy electrons almost reside in the centre region of the beam, but low-energy electrons always live in the fringe area. The energy deposition is calculated in two cases, i.e., with and without secondary electrons (SEs). Analysis indicates that the energy deposition of SEs accounts for a large part of the total energy deposition. The results of the energy spectrum show that the electrons in the inlet layer of the low-pressure chamber (LPC) are monoenergetic, but the energy spectrum of the electrons in the outlet layer is not pure. The SEs are largely generated at the outlet of the LPC. Moreover, both the energy distribution of BEs and the magnitude of the density of SEs are closely related to the pressure of LPC. Thus, a conclusion is drawn that a low magnitude of LPC pressure is helpful for reducing the energy loss in the LPC and also useful for greatly increasing the secondary electron density in dense air.

Key words: electron beam, discharge, plasma simulation, Geant4

中图分类号:  (Monte Carlo methods)

  • 52.65.Pp
41.75.Fr (Electron and positron beams) 52.50.Dg (Plasma sources) 52.80.-s (Electric discharges)