Plasma electron temperature of the nanosecond optical discharge at the solid target under the harmonics` radiation of Nd-laser
- General Physics Inst., Moscow (Russian Federation); and others
The experiments on the plasma heating at the plane Al and Cu targets under the nanosecond pulses of the first, second and fourth harmonics of the Nd-glass laser were carried out. As the source of radiation we used a Nd-laser, which includes master oscillator and multistage amplifier. Master oscillator, based on the Ga-Sc-Gd garnet crystal, operated on one transverse and one longitudinal mode. The pulse duration was 10 ns. Laser pulse had an asymmetric time envelope. The sharp front of the pulse (duration {approximately} 1 ns) was formed by an electro-optical shutter. The rear side of the pulse was smoother. Its shape was determined by the master oscillator generation process. After amplification in silicate glass stages and spatial filtering the laser pulse energy reached 20 J, divergence being 8{center_dot}10{sup -5} rad (wavelength 1060 nm). After the frequency conversion of the radiation by means of the KDP crystals the 2d and 4th harmonics radiation appeared with the pulse energy up to 10 J (in 4th harmonic). The irradiance of the target surface was I = (10{sup 9}{divided_by}10{sup 13}) W/cm{sup 2} the focusing spot diameter changing in the range d= 0.08{divided_by}3.1 mm.
- OSTI ID:
- 212935
- Report Number(s):
- CONF-950749--
- Country of Publication:
- United States
- Language:
- English
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