A Monte Carlo simulation of ion transport at finite temperatures

Abstract

We have developed a Monte Carlo simulation for ion transport in hot background gases, which is an alternative way of solving the corresponding Boltzmann equation that determines the distribution function of ions. We consider the limit of low ion densities when the distribution function of the background gas remains unchanged due to collision with ions. A special attention has been paid to properly treat the thermal motion of the host gas particles and their influence on ions, which is very important at low electric fields, when the mean ion energy is comparable to the thermal energy of the host gas. We found the conditional probability distribution of gas velocities that correspond to an ion of specific velocity which collides with a gas particle. Also, we have derived exact analytical formulas for piecewise calculation of the collision frequency integrals. We address the cases when the background gas is monocomponent and when it is a mixture of different gases. The developed techniques described here are required for Monte Carlo simulations of ion transport and for hybrid models of non-equilibrium plasmas. The range of energies where it is necessary to apply the technique has been defined. The results we obtained are in excellent agreement with the existing ones obtained by complementary methods. Having verified our algorithm, we were able to produce calculations for Ar + ions in Ar and propose them as a new benchmark for thermal effects. The developed method is widely applicable for solving the Boltzmann equation that appears in many different contexts in physics.

Role of pressure in transport of F- ions in BF3 gas for technological applications

“…In this work the Monte Carlo simulation technique for ion transport that accounts for finite gas temperature of the background gas particles [23] is used to calculate swarm parameters of F -ions in gas at temperature T=295 K and pressure p=133. …”

Unified solution of the Boltzmann equation for electron and ion velocity distribution functions and transport coefficients in weakly ionized plasmas

“…For all regimes, we focus on convergence of the solution, quantified by the transport quantities and the distribution function F 1 (v). These are compared with identical quantities sampled from Monte-Carlo (MC) simulations, which have been extensively benchmarked [27] and include temperature effects of the neutral background [28].…”

Cross-Section and Transport Parameters of Ne+ in CF4

“…We have used a Monte Carlo code that properly takes into account thermal collisions [10]. The code has passed all the relevant benchmarks [11] and has been tested in our work on several types of charged particles [11,12].…”