LAUSR

Impulse and mass removal rate of a spherical target irradiated by a nanosecond 1-μm-wavelength pulse laser are measured experimentally in air at ambient pressures from 10 Pa to 100 kPa. Shock waves resulting from expansion of the laser ablation plume are visualized by a Schlieren system. At the pressures between 100 Pa and 10 kPa, the shock wave is found to expand anisotropically affecting the impulse that is generated from both of ablation jet and blast wave energy. The mass removal rate is found constant up to 4 kPa and then peaking at 20 kPa because of the confinement effect.Impulse and mass removal rate of a spherical target irradiated by a nanosecond 1-μm-wavelength pulse laser are measured experimentally in air at ambient pressures from 10 Pa to 100 kPa. Shock waves resulting from expansion of the laser ablation plume are visualized by a Schlieren system. At the pressures between 100 Pa and 10 kPa, the shock wave is found to expand anisotropically affecting the impulse that is generated from both of ablation jet and blast wave energy. The mass removal rate is found constant up to 4 kPa and then peaking at 20 kPa because of the confinement effect.