Accession Number : AD0727143

Title :   Plasma Formation upon Laser Irradiation of Transparent Dielectric Materials below the Damage Threshold.

Descriptive Note : Technical rept.,

Corporate Author : MICHIGAN STATE UNIV EAST LANSING DEPT OF CHEMISTRY

Personal Author(s) : Henderson,B. E. ; Getty,R. R. ; Leroi,G. E. ; Rousseau,D. L.

Report Date : JUL 1971

Pagination or Media Count : 13

Abstract : The interaction of high power laser (ruby or neodymium-glass) radiation with ostensibly transparent materials has been the object of increasing research in recent years. Even at power levels below the threshold for either surface or internal damage, the emission of both positive and negative ions and of high energy radiation has been detected. Both linear and nonlinear absorption mechanisms have been proposed, and plasma initiation has been attributed to such factors as surface contaminants, surface defects, internal impurities, and free carrier absorption. In this paper, the experimental procedures, results, and interpretations of several of these investigations will be reviewed. Although the residual ion emission can be greatly reduced by careful pre-cleaning and handling procedures, it can not be eliminated entirely; the ramifications of this conclusion must be considered in the analysis of experiments in which damage is observed. (Author)

Descriptors :   (*COHERENT RADIATION, INTERACTIONS), (*DIELECTRICS, RADIATION DAMAGE), (*LASERS, PLASMA GENERATORS), EXPERIMENTAL DESIGN, OPTICAL MATERIALS, LIGHT PULSES

Subject Categories : Lasers and Masers
      Radioactiv, Radioactive Wastes & Fission Prod
      Plasma Physics and Magnetohydrodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE