  An improved system for creating a pulsed, low-temperature molecular beam of
OH radicals has been developed. We use a pulsed discharge to create OH from
H$_2$O seeded in Xe during a supersonic expansion, where the high-voltage pulse
duration is significantly shorter than the width of the gas pulse. The pulsed
discharge allows for control of the mean speed of the molecular packet as well
as maintains a low temperature supersonic expansion. A hot filament is placed
in the source chamber to initiate the discharge for shorter durations and at
lower voltages, resulting in a translationally and rotationally colder packet
of OH molecules.
