This title appears in the Scientific Report :
2016
Please use the identifier:
http://dx.doi.org/10.1088/07413335/58/2/025015 in citations.
Approaches to modeling of plasmas containing impurity at arbitrary concentration
Approaches to modeling of plasmas containing impurity at arbitrary concentration
A new approximate method to modeling of twoionspecies plasmas with arbitrary concentration of impurity is developed. It based on the usage of equations for the electron density and the ratio of the ion species densities as new dependent variables. In contrast to motion equations for the ion mass v...
Personal Name(s):  Tokar, Mikhail (Corresponding author) 

Contributing Institute: 
Plasmaphysik; IEK4 
Published in:  Plasma physics and controlled fusion, 58 (2016) 2, S. 025015  
Imprint: 
Bristol
IOP Publ.
2016

DOI: 
10.1088/07413335/58/2/025015 
Document Type: 
Journal Article 
Research Program: 
PlasmaWallInteraction 
Publikationsportal JuSER 
A new approximate method to modeling of twoionspecies plasmas with arbitrary concentration of impurity is developed. It based on the usage of equations for the electron density and the ratio of the ion species densities as new dependent variables. In contrast to motion equations for the ion mass velocities used normally, those for the new variables have a singularity at the Debye sheath only, as in the case of a one species plasma. Computations for the most critical situations of weak and intermediate friction between species due to Coulomb collisions reproduce nearly perfectly the results got by solving the original equations, however within a calculation time reduced by a factor of 102–103. In the case of strong friction, where ions' velocities are very close each other, the normal procedure does not converge at all, but the new one, being precise in this limit, operates very reliably. Calculations are done for conditions typical in the linear device PSI2, with deuterium plasmas seeded by neon impurity. For fixed electron and ion temperatures a critical density of impurity atoms is found, at which the electron density grows without limits. Such a catastrophic behavior does not occur if the electron and ion heat balances are taken into account to calculate the temperature profiles selfconsistently. 