Nitrogen influences on a laser produced TMAE plasma

Summary form only given. TMAE is a readily ionized organic gas, tetrakis(dimethylamino)ethylene, which can be single photon ionized by a 193 nm laser, so that a large volume (hundreds of cm/sup 3/), high initial plasma density (>10/sup 13/ cm/sup -3/) plasma can be created. Additional high pressure nitrogen admixture effects in this plasma are studied by measuring planar Langmuir probe electron saturation currents: which provide more reliable electron density measurements than those from ion saturation current, because the former is not dependent on ion species but the latter is. The former is much more difficult in the experiment due to the difficulty of accurately identifying the electron saturation current: but we have got very flat curves of the electron saturation current vs. the bias voltage so that the electron saturation currents can be accurately identified. The technique of these fast probe measurements which include a detailed considerations of probe structure, probe surface cleaning, shielding, probe perturbation, frequency response. Temporal and spatial resolutions, dummy probe corrections as well as noise analysis will be shown. The electron densities and temperatures vs. time at different TMAE pressures, nitrogen pressures and laser powers will be present.