Title :
Ionization equilibrium in multicharged ion plasma with fast electrons
Author :
Zakharov, Vasily S. ; Novikov, Vladimir G.
Author_Institution :
Keldysh Inst. of Appl. Math., Moscow
Abstract :
Summary form only given. Discharge and laser produced multicharged ion plasmas often have nonequilibrium electron distributions with fast (high energy) electrons that may have a profound effect on ionization balance. In the report the influence of high energy electrons on ionization balance in the collision-radiation equilibrium model for the optically thin plasma is considered. NonMaxwellian electron distribution by the energy, found out by adding of fast electrons with various concentration and energy, used for calculations of impact processes rates on the basis of Hartree-Fock-Slater (HFS) quantum-statistical model in the average ion approximation. The calculation approach for the rates of inelastic electron-ion interaction processes with arbitrary electron distribution function based on the method of distorted waves (DW) with the using of numerical and semiclassic wave functions for discrete and continuous spectra calculated in self-consisted HFS potential. Results of calculations of the ionization equilibrium in argon plasma in the temperature range of 5-1000 eV with fast electrons with energies from 1 to 10 keV and relative concentrations 0.1-10% are analyzed. Basically, the calculations for the density of electrons ~10 18 cm-3 were made. It is shown that fast electrons increase the impact ionization rates in multicharged ion plasma and consequently significantly change its ionization equilibrium state
Keywords :
argon; impact ionisation; plasma collision processes; plasma density; plasma kinetic theory; plasma sources; plasma temperature; 1 to 10 keV; Ar; Hartree-Fock-Slater model; average ion approximation; collision-radiation equilibrium model; continuous spectra; discharge plasmas; discrete spectra; distorted waves; electron density; impact ionization; inelastic electron-ion interaction; ionization equilibrium; laser produced multicharged ion plasmas; nonMaxwellian electron distribution; nonequilibrium electron distributions; optically thin plasma; quantum-statistical model; semiclassic wave functions; Charge carrier processes; Distribution functions; Electron optics; Ionization; Laser modes; Optical distortion; Particle beam optics; Plasma density; Plasma temperature; Wave functions;
Conference_Titel :
Plasma Science, 2006. ICOPS 2006. IEEE Conference Record - Abstracts. The 33rd IEEE International Conference on
Conference_Location :
Traverse City, MI
Print_ISBN :
1-4244-0125-9
DOI :
10.1109/PLASMA.2006.1706975