Enhancement of Kr/sub 2/ excimer generation in a pulsed rare-gas jet discharge with H/sub 2/ gas contact cooling

A novel excitation scheme for Kr/sub 2/ rare-gas excimer formation is developed. A pulse discharge excited Kr jet is dynamically mixed with a H/sub 2/ neutral gas flow located downstream in a vacuum chamber. Rapid contact cooling of the high temperature Kr plasma jet by H/sub 2/ gas collisions increases the Kr/sub 2/ excimer emission at 148 nm by a factor of more than three compared with that observed without the cooling downstream. Significant decreases of both electron temperature and density in the Kr plasma when mixed with H/sub 2/ gases downstream are measured with time-resolved spectroscopic methods.<
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