By using a Langmuir probe, the electron energy distribution function (EEDF) is measured in inductively coupled plasma discharges in N2/Ar mixtures at 200W rf powers. In pure N2 discharges a Maxwellian EEDF is observed. When the mixing ratio of Ar increases, the distribution of high-energy electrons evolves with a dierent trend from that of low-energy electrons, resulting in an apparent "two temperature structure" of the EEDF We discuss this non-Maxwellian EEDF and its effect on the measurement and the interpretation of "electron temperature" by both the probe and line ratio technique.

Experiments on the deposition of GaN thin films were carried out in an ECR plasma reactor using nitrogen gas and Trimethylgallium MG.as precursors. Electron temperature and nitrogen species adjacent to the substrate surface during deposition were measured by a CCD spectrometer. We observed an optimum electron temperature for the growth rate. The result suggests that tuning of electron energyor temperature. can be used to optimize the deposition and electron temperature near the substrate surface may be a candidate for one of the control parameters in plasma-assisted CVD.

Experiments were performed on an atmospheric pressure glow discharge (APGD) in an air gap between two dielectric barrier electrodes. While it is possible to get an APGD in a 2mm air gap, it is possible to get only a filament discharge in a 5mm air gap. The development of an electron avalanche in such a gap was numerically simulated. It was found that the critical applied field for a 5mm electron avalanche to transit to a streamer is equal to 35.07kVcm-1. This calculated critical applied field is in good agreement with the experimental one. The experimental and theoretical results confirm that only a filament discharge, rather than a glow discharge, can be produced in an atmospheric pressure air gap that is not less than 5mm if it is not possible to lower the breakdown field of air. A resistive barrier discharge (RBD) was theoretically analysed and the development of RBD was numerically simulated. If a kilohertz discharge is required, the parameters of the resistive layer should be in the rangeρεr=(109-1011)Ωcm. APGD in a helium gap was realized using 50Hz line power with a suitably fabricated resistive layer.

Polymer coating on the surface of inorganic ceramic nanoparticles is beneficial to decrease agglomeration and improve dispersion in organic solvent in ceramic injection moulding technology. A layer of thin polymer film on zirconia nanoparticles is deposited by inductively coupled ethylene/nitrogen plasma. Transmission electron microscopy photographs indicate the presence of uniform polymer coatings and the thickness of the polymer layer is estimated as several nanometers. The chemical structure of the film is revealed as quasi-polyethylene long hydrocarbon chain by x-ray photoelectron spectroscopy examination.

Using a technique applied previously to vibrationally excited molecular nitrogen (N*2) in the region of daytime and nighttime aurora, the emission intensity of the N2 second positive band system in an inductively coupled plasma (ICP) has been analysed and the vibrational temperature of nitrogen molecules in the ICP is thus determined. The result shows that the vibrational temperature increases with the increase of the neutral gas pressure from 0.04Pa to 10Pa, then decreases with the further increase of the pressure from 10Pa to 100Pa. Also, this is explained by using the Boltzmann relation between the vibrational temperature and the concentration of the vibrationally excited N*2 (X1+g) molecules.

A new technique, adding argon or helium into nitrogen plasma, has been used to regulate the electron temperature in an inductively coupled plasma. The electron temperature is determined by analysing the intensity ratio of two nitrogen spectrum lines. The results show that, when the total pressure is 0.7Pa, the electron temperature increases with the increase of the He partial pressure in He/N2 plasma, but the electron temperature decreases with the increase of the Ar partial pressure in Ar/N2 plasma. The regulation e ect of electron temperature is weaker in higher pressure N2/He plasma of 2.6Pa.

Experiments have been conducted on Constance B to study transport properties in electron cyclotron resonance (ECR) heated plasmas of high-charge-state neon ions. Measurements were made of confinement parallel and perpendicular to the magnetic field at heating frequencies of 10.5 and 14 GHz, and corresponding ECR magnetic field strengths. Although radial ion losses scaled approximately as B-2, the total particle confinement time was independent of magnetic field. Thus, higher current densities of mulficharged neon ions were extracted at higher ECR heating frequency and magnetic field.

Emission spectroscopy is used to investigate the effect of inert gas mixing in nitrogen plasmas generated in inductively coupled plasma (ICP) and electron cyclotron resonance (ECR) plasma sources. Vacuum ultraviolet (VUV) emission of resonance lines is used to determine concentration of atomic nitrogen while electron temperature is obtained from optical emission spectra. It is found that electron temperature can be either raised or reduced effectively by mixing helium or argon in a nitrogen discharge. Electron-electron collisions and superelastic collisions involving metastable species are key factors in electron temperature tuning.