A Simplified Approach to Describing the Kinetic Properties of Impurity Ions in a Weakly Ionized Helium Plasma

Plasma Physics Reports. 2024. Vol. 50. No. 12. P. 1577–1584.

Aleksandrov N., Ponomarev A.

Using an approximate approach that is valid for a large ratio of the ion mass to the mass of the neutral
particle, the mobility of O2+, N2+, O2-, and O4- ions was calculated in helium and good agreement was
obtained with the available results of Monte Carlo calculations and experimental data at high values of the
reduced electric field. This simplified approach was used to determine the average energy of O4- ions and the
rate constants of dissociation of these ions in helium. The obtained ion characteristics were compared with
the results of more accurate calculations using the Monte Carlo method. Good agreement has been obtained
between these two approaches for the average ion energy, but for the dissociation rate constant the difference
is quite significant, reaching an order of magnitude or more. It was shown that this difference is associated
with the peculiarities of the energy distribution of ions for a large ratio of the ion mass to the mass of the neutral
particle.

Keywords: метод Монте-Карло, Monte Carlo method, molecular ion dissociation, ion mobility, weakly ionized helium plasma, ion energy distribution, подвижность ионов, диссоциация молекулярных ионов, слабоионизованная плазма гелия, распределение ионов по энергии