Modeling and Diagnostics of Low Pressure Inductively Coupled Plasmas

Striations in rare gas plasmas

“…Since electrons 'remember' their energy, f 0 (v, r, t) is determined not only by plasma properties at a given point but also by the properties in the vicinity of the size λ u . In this collisional non-local regime, hydrodynamic models cannot adequately describe electrons, and a number of interesting kinetic effects take place [30,69]. With the further decrease in p , the electron mean free path becomes comparable to or larger than the characteristic size of the plasma, λ e .…”

Electron Kinetics in Radio-Frequency Atmospheric-Pressure Microplasmas

“…Despite the nonequilibrium character of the low-temperature microplasmas, most studies found in the literature are based on fluid models. Kinetic effects not captured by hydrodynamic models, however, can be important in nonequilibrium discharges [5][6][7][8][9][10][11]. Thus, a kinetic analysis is required to validate existing fluid results [2,12 -15], determine the EEPF in microdischarges, and reveal the mechanisms leading to its formation.…”

“…In microdischarges, however, low-energy electrons may not be in local equilibrium either [18]. In fact, lowenergy electrons in the 100 and 75 m discharges can transit the confining ambipolar potential well without significant energy loss; i.e., they are in the nonlocal regime [5]. In other words, the energy relaxation length of lowenergy electrons is comparable to or larger than the width of the confining potential well [ " " > L well "].…”

“…Besides relaxing their energy in a fraction of a rf cycle ( 1 ns), midenergy electrons are also lost to the electrodes when the sheaths collapse. The separation between the mid-and high-energy electrons at 20 eV corresponds to the helium excitation threshold and as in lowpressure discharges, the ''knee'' in the EEPF is due to the faster energy relaxation of electrons in the inelastic energy range [5].…”