Two-dimensional structure of PDP micro-discharge plasmas obtained using laser Thomson scattering

Laser Thomson scattering (LTS) has been applied for measurements of the electron density and electron temperature in micro-discharge plasmas for plasma-display panel research. A brief description of the method for overcoming the sparsity of scattered photons by the data accumulation technique is presented. Then, the technique of applying LTS to micro-discharge plasmas is described where the use of a specially designed triple-grating spectrometer has turned out to be essential. Improvements in the experimental setup to allow, for the first time, to collect laser LTS spectra at heights as close as to 60 μm from the electrode surface are discussed. Spatial distributions of the electron density and electron temperature in the vertical direction above the electrode surface are presented. Finally, an extension of the measurements into two-dimensions, namely along the electrode surface and at different heights above the electrodes enabling to cover the discharge front to be made, are presented and compared with the results of optical emission measurements.