Journal of Physical Chemistry A, Vol.102, No.48, 9696-9701, 1998
Controlling the orientation of hexapole-selected hydroxyl (OH) radicals
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 Lambda-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.
Keywords:LASER-INDUCED FLUORESCENCE, QUANTUM SCATTERING CALCULATIONS;SYMMETRICAL-TOP MOLECULES, STATE CROSS-SECTIONS, REACTIVESCATTERING, LAMBDA-DOUBLET, BRUTE FORCE, ALIGNMENT, BEAMS;DYNAMICS