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Triple Langmuir probes were used to measure electron number density, and electron temperature in the near-exit region of a laboratory model gas-fed pulsed plasma thruster. Triple Langmuir probe data was obtained on a plane parallel to the thruster electrodes at radial distances of 3 and 7 cm downstream of the propellant inlet and angular positions of 0, 10,20, and 30 degrees. The thruster was operated with Xe propellant, 2 J per pulse, and a mass flow rate of 3 mg/s. Analysis shows that average density at the thruster exit plane is in the range of 5x10" to 2.5~10'~ mv3 and temperature is in the range of 0.5 to 4 eV. At a radial distance of 4 cm downstream from the exit, the density is in the range of 2x10" to 1~10'~ mm3 and temperature in the range of 0.2 to 1.4 eV. Temperature averaged over the duration of a pulse is in the range of 0.4 to 1.3 eV and shows angular and radial variation.

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