Study of the Electron Velocity Distribution Function in Weakly Ionized Radiofrequency Plasma

One of the most important characteristics of low-temperature plasma is the electron energy distribution function (EEDF) or the velocity distribution function. This work examines the influence of the electromagnetic field on the values of the electron velocity distribution function (EVDF) at pressures from 13.3 to 133 Pa for electric field strengths from −3000 to 3000 V/m in a radiofrequency (RF) discharge with a degree of ionization of 10⁻⁶–10⁻⁴. It has been shown that at low frequencies of the RF electromagnetic field (0.44–1.76 MHz) and a decrease in the collision frequency to 5 × 10⁷ Hz, the deviation of the EVDF from the Maxwellian EVDF comes to 35% with an increase in the absolute value of field strength to 3000 V/m. This has a significant impact on the diffusion and mobility coefficients, the difference in which can be up to 25% in the considered range of parameters.