Spectroscopic analysis of the cathode jet of a model coaxial magneto- plasma dynamic (MPD) thruster is conducted to determine electron density and temperature downstream from the cathode. H(Beta) line profiles were scanned from an argon-hydrogen plasma generated in the cathode test facility of the NASA Jet Propulsion Laboratory in Pasadena, CA. A computer program was written in IDL to determine the profile Doppler and Stark half widths, which were used to determine temperature and electron density, respectively. Three sets of data from the cathode test facility were taken, while varying operating voltage, current, hydrogen/argon ratio, and pressure. Radial profiles for electron density and temperature were determined within the cathode jet. Generated plasmas ranged in electron density and temperature from approximately Ne = 2 x 10(14) cm( -3) at 5000 K (0.43 eV) to 4 x 10(14) cm( -3) at 15600 K (1.3 eV). It was determined that radial density and temperature distribution within the cathode jet are essentially uniform.