| Summary: | 博士 === 國立中山大學 === 化學學系 === 82 === Combining laser sheet illumination and two-dimensional image
techniques, photofragmentation of ICN at 248 nm was studied in
great details. The three-dimensional distribution of number
density, angle and velocity of state-selected CN photofragments
was successfully determined by slicing an expanding, spherical
shell from the photodissociation center sequentially. A
physical model was developed to correlate the photodissociation
dynamics and image patterns from this direct method. Slicing
an expanding Newton sphere of state- selected photofragments by
the pulsed laser sheet at various delay times relative to the
photolysis event, we simulated numerically the resultant image
frames in velocity space. To accommodate realistic experimental
conditions, intensity patterns which take into account
contributions from internal energy and velocity distributions
of precursors and an assembly of photolysis centers on an arc
were presented. In the framework of the imaging model, time-
resolved image patterns from photofragmentation of ICN were
employed to illustrate the influence of internal energy and
velocity distributions of precursors.
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