Discharge singlet oxygen generator for oxygen-iodine laser: II. Two-dimensional modelling of flow oxygen rf plasma at 13.56 and 81 MHz power frequency

摘要

A 2D self-consistent simulation of an rf discharge in a gas flow in pure oxygen over a wide range of discharge parameters was carried out. The simulation was made at the experimental conditions of Part I of this paper for the discharge tube with an HgO coating where the most effective production of O-2(a(1)Delta(g)) was experimentally observed. The simulation goal is to study the features of transversal rf discharge self-organization at different rf frequencies, 13.56 and 81 MHz, to reveal the most optimal conditions for both the O-2(a(1)Delta(g)) yield and its energy efficiency. It was shown that the energy part absorbed by electrons increases with the frequency. The spatial discharge structure was studied at both frequencies. It was revealed that at the higher rf of 81MHz the discharge operates in a mode of the normal current density even at high input powers. The kinetic processes which determined both O-2(a(1)Delta(g)) loss and production at experimental conditions were studied and discussed. The increase in rf frequency from 13.56 to 81MHz reveals an increase in the SO yield and efficiency. It also connects with the decreasing of input energy losses in the sheaths.