Laser induced fluorescence measurement of ion velocities in the plume of a hall effect thruster
Laser induced fluorescence (LIF) was used to measure the mean and variance of the velocity distribution of xenon ions in the plume of the P5 Hall thruster. The data indicate an acceleration region extending several centimeters downstream of the exit plane. Significant plume divergence and spreads in velocities equivalent to about 1 eV were observed. Speeds measured correspond to ion energies smaller than those measured with molecular beam spectroscopy at similar points of interrogation in the plume. LIF measurements taken 10 to 50 cm downstream indicate that the “spike” observed in the plume is a region of interaction caused by inward divergence from the discharge annulus. © 1999 by the American Institute of Aeronautics and Astronautics, Inc.
