Controlling the Orientation of Hexapole-Selected Hydroxyl (OH) Radicals

摘要

Recently, Hain, Toby D.; Weibel, Michael A.; Backstrand, Kyle M.; and Curtiss, Thomas J. J. Phys. Chem. A 1997, 101, 7674 reported the production of intense, rotationally state-selected, supersonic beams of hydroxyl radicals via electric hexapole focusing. Here, a detailed description of the lab frame orientation of selected radicals is provided. The distribution of orientations can be systematically varied with the electric field strength in a post-hexapole scattering region. This control of orientation results from the field-dependent mixing of the different parity states comprising the OH Λ-doublets. Calculated fluorescence yields show polarization-dependent LIF measurements probe the alignment terms of the orientation distribution, and field-dependent measurements probe the parity state composition.