Experimental scaling laws for ablation parameters in plane target--laser interaction with 1. 06. mu. m and 0. 35. mu. m laser wavelengths
Ablation parameters such as velocity, mass, momentum, pressure, and hydrodynamic efficiency have been investigated with plane targets irradiated in the range 3 x 10/sup 11/-10/sup 15/ W cm/sup -2/ with 1 nsec pulses and laser wavelengths of 1.06 ..mu..m and 0.35 ..mu..m. We show that ablation velocity, ablated mass, and momentum are in good agreement with ablation scaling laws deduced from analytical models taking into account inverse bremsstrahlung absorption below the critical density. Nevertheless, processes such as lateral conduction, hot spot, and preheat effects make inaccurate the comparison between ablation pressures, mass ablation rates, or hydrodynamic efficiencies measured for different laser wavelengths. Laser illumination nonuniformities are transmitted to the target in terms of pressure variations. The harmful consequence of a reduced lateral energy flow in 0.35 ..mu..m experiments can eclipse the increasing of ablation pressure and hydrodynamic efficiency.
- Research Organization:
- Commissariat a l'Energie Atomique, Centre d'Etudes de Limeil, 94190 Villeneuve-Saint-Georges, France
- OSTI ID:
- 5508383
- Journal Information:
- Phys. Fluids; (United States), Vol. 27:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
LASER-PRODUCED PLASMA
EFFICIENCY
MASS
PLASMA PRESSURE
SCALING LAWS
VELOCITY
ABLATION
ACCURACY
CORRELATIONS
INFRARED RADIATION
PLASMA DIAGNOSTICS
PULSES
VISIBLE RADIATION
ELECTROMAGNETIC RADIATION
PLASMA
RADIATIONS
700102* - Fusion Energy- Plasma Research- Diagnostics