Using A High Repetition Rate Nd: YAG Laser For Pulsed Laser Ablation Propulsion

Abstract

Laser propulsion is a relatively new technology being researched for its vast potential. A test apparatus was developed to measure small forces using piezoelectric films and a developed amplifier tuned to the specific frequencies expected from the system. The system provided consistent results comparable to published values. The tests conducted in this thesis evaluated the effects of using a high repetition rate laser for laser propulsion. The results are on the micropropulsion scale, however, the findings are expected to perform similarly on a larger scale. The thrust, moment coupling coefficient, and specific impulse values were evaluated for aluminum, brass, and PVC of differing thicknesses. The results concluded that the repetition rate in fact did not have much effect on the thrust; thrust was primarily dependent on the pulse energy and the material thickness. The repetition rate was found to affect the specific impulse values; a result of the heat affected zone created by the laser ablation, thereby reducing the effective propellant used for propulsion.