Nonlocal Ionization Theory and Secondary Electron Emission Coefficient: Application in Helium and Neon DC Microdischarge at High Pressure

In this article, we are interested in giving a detailed study of the nonlocal ionization theory (NIT) and their secondary electron emission coefficient (SEEC). As for expelling, we present the spatial distributions of both Coulomb logarithm of electron-electron and electron-ion collisions, ionization and excitation frequency ratios, and source term of particle charged, as well as ion temperature in helium and neon dc microdischarge at high pressure. The pressure range is from 40 to 70 torr, and the applied potential is from 200 to 230 V. In the framework, we have developed an empirical expression of the secondary electron emission corresponding to the helium and neon discharge. The current-voltage results are in good agreement with the experimental data. We have computed the real ion temperature using the generalized Einstein's relation, and in my knowledge, this is for the first time in the literature. As a result, the helium ion temperature reached 34 times the gas temperature at the cathode and reached 56 times the gas temperature in neon.