Formation of a Noncrystalline Phase in Aluminum Irradiated with a Pulsed Ruby Laser

Abstract
Polycrystalline aluminum samples have been irradiated with very short (15-ns time duration) pulses from a ruby laser. After irradiation, we have detected the formation at the Al surface of a noncrystalline layer, about 1500 Å thick. This layer has been characterized by transmission electron microscopy, x-ray diffraction, and nuclear reactions. Perliminary results are also presented on the behavior of heavily Cu- and Pb-doped Al polycrystalline samples after being irradiated under the same conditions as the pure Al samples.