We describe a new instrument based on a delay-line detector for imaging the complete three-dimensional velocity distribution of photoionized products from photoinitiated reactions. Doppler-free resonantly enhanced multiphoton ionization (REMPI) of H and D atoms formed upon photolysis of HBr and DBr in the range yields radial speeds measured to be accurate within 1% of those calculated. The relative speed resolution is about 5% and limited by photoionization recoil broadening. A relative speed resolution of 3.4% is obtained for REMPI, which minimizes the ionization recoil. We also determine the branching ratio between ground-state and spin-orbit-excited product channels and their associated anisotropies. We find that DBr photolysis dynamics differs slightly from its HBr counterpart.
Construction and calibration of an instrument for three-dimensional ion imaging
Konrad Koszinowski, Noah T. Goldberg, Andrew E. Pomerantz, Richard N. Zare; Construction and calibration of an instrument for three-dimensional ion imaging. J. Chem. Phys. 7 October 2006; 125 (13): 133503. https://doi.org/10.1063/1.2217742
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