Excited level populations of argon atoms in a non-isothermal plasma

Abstract

The numerical method presented makes it possible to solve numerous rate equations for excited level populations together with the Boltzmann equation for the electron energy distribution function and thus to extend the applicability of the existing extensive collisional-radiative models for rare gas plasmas to the region in which the assumption of the Maxwellian distribution function is not justified. Computations performed on the basis of the argon atom model consisting of 65 discrete effective levels provide information about mechanisms populating the excited levels under various conditions in non-isothermal argon plasmas and about the effects caused by the departures of the actual electron distribution function from the corresponding Maxwellian function on excited level populations and on volume collisional-radiative recombination and ionisation coefficients in these situations.

A spatially resolved relaxation method for pLTE plasma diagnostics in free-burning arcs

“…On the other hand, b shows strong dependences on both z and r, so that it still abides a monotone curve progression. In spite of these problems, the values we obtained for b seem to be reasonable when comparing them with experimental data in [22] or calculated data in [60].…”

Spectroscopic Measurement of Electron Temperature and Density in an Argon Plasma Jet Based on Collisional-Radiative Model

“…In this study, radiative transitions are assumed to be perfectly optically thin except for the transitions to the ground level in the CR model. Vlček and Pelikán [16] performed the CR calculation of atmospheric and sub-atmospheric pressure arc plasmas under this assumption, and they reported that both population densities by CR calculation and those obtained by experiment agreed well. Although the pressure of our Ar plasma was 22.6 Pa, the measured line intensities between excited states might be affected by the reabsorption in our plasma since the radius of the plasma was 3 cm.…”

Optical Measurements of High-Density Helicon Plasma by Using a High-Speed Camera and Monochromators

“…S Ii (T e , n e ) and S IIi (T e , n e ) are calculated from the CR model, and are generally dependent on T e and n e . In the present study, T e extends above 2 eV and 10 17 ≤ n e [m −3 ] ≤ 10 19 , corresponding to the condition for the non-saturated phase of the ionizing plasma, where the population kinetics of the excited states are not saturated in terms of electron collision processes for the Ar plasma [5]. Under this condition, S Ii (T e , n e ) and S IIi (T e , n e ) are approximately proportional to n e , and consequently Eq.…”