Several Theories In The Low-temperature Plasma Applications Problems

Low-temperature plasma is very important in microelectronics, fabricating materials, protecting environment, aviation and military. However many theoretical problenis have not been solved. The classification and several usual industrial applications of low-temperature plasma are presented in chapter one of the first part of this Ph.D. dissertation. In chapter two, the applications of low-temperature in protecting environment and communication are briefly narrated. Plasma chemistry is outlined in chapter three. Chapter four is devoted to plasma cloaking. The research status of dusty plasma physics is reviewed in chapter five.Dust is quite significant in plasma processing, so two specific subjects, the effects of dust on ion transport (in chapter six) and low-frequency electrostatic waves in a collisional dusty plasma (in chapter seven), are described in detail in part two of the Ph.D. dissertation. As for ion transport, Monte Carlo method has been used to simulate the ion transport in a parallel plate rf glow discharges with dusts. A self-consistent electric field is taken into account. The charge exchange and elastic collision between ion and neutral atoms and the collection and Coulomb scattering of ion on dust grains are considered. Four new results are obtained in this simulation: (1) When the dust density, size, and/or charge increase, the energy distribution of ion arriving at the target transfers to low energy region. (2) As dust concentrationn_d/n_i0 rises, the ion density at the target drops exponently. (3) As dust size goes up,the ion density at the target also go down exponently. (4) As dust density, as well as size, increases, the ion density at the target decreases more quickly than increasing either of them. Therefore, though the dust concentration is very low (a few thousandth), its effects on lots of plasma processes cannot be neglected. For the low-frequency waves, a dispersion relation is derived from the set of continuity, momentum, and energy equation, together with Poisson equation. It is found that there exist three modes in a magnetized, homogeneous, and collisional dusty plasma:...