KYLE N. CRABTREE, CARRIE A. KAUFFMAN, Department of Chemistry, University of Illinois, Urbana, IL, 61801; BENJAMIN J. MCCALL, Departments of Chemistry and Astronomy, University of Illinois, Urbana, IL, 61801.
We have recently constructed a prototype continuous supersonic expansion discharge nozzle for the production of rotationally cold molecular ions. To assess the performance of this source, we have employed laser-induced fluorescence spectroscopy to measure the rotational temperature distributions of I2 and N2+ as a function of position within the expansion. These measurements are performed on the B3 _0u+ - X1 g+ (6-0), (8-1), (10-2), and (12-3) bands of I2 at 608 nm and the A2 u - X2 g+ (4-0) band of N2+ at 614 nm using a tunable cw dye laser. The temperature distributions obtained act as a feedback mechanism that aids in refinement of the source design with the aim of optimizing the densities and temperatures of the species within the expansion.