Accession Number : AD0655105

Title :   CHARGED PARTICLE EMISSION AFTER RUBY LASER IRRADIATION OF TRANSPARENT DIELECTRIC MATERIALS.

Descriptive Note : Technical rept.,

Corporate Author : PRINCETON UNIV N J FRICK CHEMICAL LAB

Personal Author(s) : Rousseau,D. L. ; Leroi,G. E. ; Falconer,W. E.

Report Date : JUN 1967

Pagination or Media Count : 29

Abstract : Ion currents induced by high power laser irradiation of transparent dielectric materials in vacuo below the threshold for physical damage have been investigated. Soft glass, Pyrex, fused quartz, Supracil quartz, CaF2, LiF, and sapphire all show similar behavior. Currents as large as 10 billion ions/pulse are obtained using ruby radiation with normal mode power levels of about 200 kW. Both positive and negative ion signals were studied, and for the latter case two distinct signals have been time resolved using Q-switched pulses. The emission is qualitatively similar to related investigations of laser irradiated metal surfaces. These effects are ascribed to laser heating of dust and other surface contaminants with subsequent production of high energy photons and thermionic emission of electrons and ions. The emission of photons, electrons and ions can be reduced, but not completely eliminated, by careful precleaning and repeated lasing on the dielectric surface. (Author)

Descriptors :   (*THERMIONIC EMISSION, *LASERS), (*DIELECTRICS, THERMIONIC EMISSION), CHARGED PARTICLES, EMISSIVITY, FIELD EMISSION, GLASS, QUARTZ, CALCIUM FLUORIDES, LITHIUM FLUORIDES, COHERENT RADIATION, PHOTONS, DAMAGE, RADIATION EFFECTS

Subject Categories : Lasers and Masers
      Nuclear Physics & Elementary Particle Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE