Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)



Committee Chair

James A Miller

Committee Member

Massimiliano Bonamente

Committee Member

Seyed Sadeghi

Committee Member

Lingze Duan

Committee Member

Henry Everitt


Laser ablation., Propulsion systems., Plasma engineering.


The efficacy of utilizing material ablation from picosecond laser pulses onto elemental metal targets for propulsion applications is studied by a variety of measurement methods to characterize laser ablation plume dynamics. A 100 ps, 532 nm laser is used for ablating elemental metals, and the resulting ablation plume dynamics are measured by time-of-flight (TOF) energy analyzer probes, a piezoelectric force sensor, and an intensified imager. Results indicate that plume dynamics exhibit a material dependence and behave in a manner indicative of laser-induced plasma formation and expansion, and indicate that ablation-based laser propulsion is characterized by high specific impulses (on the order of 10^3 s) due to the high plume velocities measured. An efficiency analysis is performed comparing input laser energy to plume kinetic energy, showing that aluminum is the best-suited material for laser ablation propulsion. A demonstration is constructed and performed showing proof of this concept. Further experiments are performed to measure the optimal pulse length and to use pump-probe pulse configurations to enhance the ablation plume dynamics. Results indicate that despite some ion population and velocity gains using delayed pump-probe pulse sequencing, measured forces show a corresponding reduction in applied thrust, and hence any enhancements are unlikely. In the course of these measurements, an ablation energy loss mechanism known as time-delayed phase explosions was discovered, and results are shown to challenge existing phase explosion theory.



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