ISSN:
1089-7674
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Electron density measurements from previous ion-beam-induced gas ionization experiments [F. C. Young et al., Phys. Plasmas 1, 1700 (1994)] are re-analyzed and compared with a recent theoretical model [B. V. Oliver et al., Phys. Plasmas 3, 3267 (1996)]. Ionization is produced by a 1 MeV, 3.5 kA, 55 ns pulse-duration, proton beam, injected into He, Ne, or Ar gas in the 1 Torr pressure regime. Theoretical and numerical analysis indicates that, after an initial electron population is produced by ion beam impact, ionization is dominated by the background plasma electrons and is proportional to the beam stopping power. The predicted electron density agrees with the measured electron densities within the factor of 2 uncertainty in the measurement. However, in the case of Ar, the theoretically predicted electron densities are systematically greater than the measured values. The assumptions of a Maxwellian distribution for the background electrons and neglect of beam energy loss to discrete excitation and inner shell ionization in the model equations are considered as explanations for the discrepancy. © 1999 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.873203
Permalink