UBC Theses and Dissertations
An attampt to measure the electron temperature of a Xenon Chloride excimer laser discharge plasma by Thomson scattering Hughes, Michael K. Y.
An electronic timing system was developed so that a commercial Nd:YAG regenerative amplifier could be triggered remotely with a BNC cable and pushbutton switch. This system was used to accurately time a Xenon Chloride transverse discharge laser to the short, high power Nd:YAG pulse to within 5 ns. Attempts were made to determine the electron velocity distribution of the discharge plasma of this Xenon Chloride laser using the method of Thomson scattering. The Thomson scattering parameter a was 0.22. A short, 532 nm pulse was injected into the excimer laser and the backscattered light was analysed. The scattered beam was imaged onto the entrance slit of a spectrometer and the spectrally dispersed output was collected by either a streak camera or a photomultiplier array. The injection laser pulses were produced by amplifying the 100 Ps pulses from a modelocked Nd:YAG laser in a regenerative amplifier giving probe pulses of approximately 40 mJ in 100 Ps at the excimer laser. Aside from the signal intensity at shifted wavelengths which was measured to give an estimate of the electron temperature, the relative timing of the probe pulse to the excimer current was measured to give a time profile of the temperature. The injection pulse power and excimer laser current were also needed to ensure that results behaved as predicted in relation to these parameters. The temperature measurements proved to be impossible due to extremely high noise levels, a lack of resolution of the spectrometer and possibly laser heating effects.
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