Experimental investigation of the interaction between laser radiation and a target in air

Journal Article · Mon Sep 01 04:00:00 EDT 1975 · Sov. J. Quant. Electron. (Engl. Transl.), v. 5, no. 9, pp. 1048-1054

DOI:https://doi.org/10.1070/QE1975v005n09ABEH011891· OSTI ID:4075416

Kozlova, N N; Markovich, I E; Nemchinov, I V; Petrukhin, A I; Pleshanov, Y E; Rybakov, V A; Sulyaev, V A

An investigation was made of the interaction of laser pulses of 1 $mu$sec duration and up to 30 J energy with a target in air on which the laser radiation focused in a spot of 5--8 mm diameter. The shape of a plasma jet formed on the target, velocity of the plasma front and shock wave, brightness temperature, and pressure were determined at different moments. The experiments were carried out in the power density range from 10 to 300 MW/cm$sup 2$ and the illumination in the focal spot was almost uniform. The results obtained indicated that up to about 100 MW/cm$sup 2$ an absorption wave formed in the leading edge of an opaque (for the incident radiation) jet and this wave was preceded by a transparent shock wave. The expanding plasma jet acted as a piston on the surrounding cold layers (''expulsion regime''). At higher power densities a detonation regime was observed and it was complicated by radiative energy transfer at wavelengths corresponding to the continuous spectrum of the hot plasma. During the initial part of a radiation pulse the flow conditions were nearly planar but as the jet rose above the target to distances of the order of illuminated spot size, the motion became two-dimensional. (AIP)

• Research Organization: O. Yu. Shmidt Institute of Terrestrial Physics, Academy of Sciences of the USSR
• Sponsoring Organization: USDOE
• NSA Number: NSA-33-016800
• OSTI ID: 4075416
• Journal Information: Sov. J. Quant. Electron. (Engl. Transl.), v. 5, no. 9, pp. 1048-1054, Journal Name: Sov. J. Quant. Electron. (Engl. Transl.), v. 5, no. 9, pp. 1048-1054; ISSN SJQEA
• Country of Publication: United States
• Language: English

Related Subjects

*LASER-PRODUCED PLASMA
*PLASMA JETS
700106* --Fusion Energy--Plasma Research--Plasma Production
AIR
N70600* --Physics--Controlled Thermonuclear Research-- Production
PLASMA DENSITY
PLASMA EXPANSION
TARGETS