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Several applications of PIC simulations for understanding basic physics phenomena in low-temperature plasmas are presented: capacitive radiofrequency discharges in Oxygen, dusty plasmas and negative ion sources for heating of fusion plasmas. The analysis of these systems based on their microscopic properties as accessible with PIC gives improved insight into their complex behavior. These studies are results of joint efforts over about one decade

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In this paper we present a parametric study of the effect of discharge voltage on capacitively coupled, parallel plate (CCPP) radio frequency discharges in pure hydrogen at low pressure, performed using a 1D(r)2D(v) particle in cell/Monte Carlo collision model with self-consistent neutral kinetics and also compare our results with experimental and theoretical ones reported in the literature. In the first part of the paper, we review the essential features of the numerical code, together with the database of plasma particles and neutral kinetics data. Results are discussed, in particular, for charged particle density and energy, the appearance of the double layer phenomenon, the plasma potential and the atom density. A possible role of photoelectric emission in the charged particle balance is also discussed.

Old and new problems in the physics of multicusp magnetic sources for the production of negative H -/Dions are presented and discussed. We emphasize particularly, in this kind of plasmas, both the vibrational and electron non equilibrium energy distributions, the role of Rydberg states in enhancing the negative ion production, the production of vibrationally excited states by the Eley-Rideal mechanism, and the enhancement of negative ion concentrations in pulsed discharges. In appendix I recent cross sections calculations for elementary processes and the theoretical determination of hydrogen recombination probability on graphite surface are illustrated. In appendix II two types of sources are modeled: the first one is a classical negative ion source in which the plasma is generated by thermoemitted electrons; in the second one, electrons already present in the mixture are accelerated by an RF field to sufficiently high energy to ionize the gas molecules.