Accession Number : ADA302772
Title : The Role of Valence-Band Excitation in Laser Ablation of KCl.
Descriptive Note : Rept. for 1 Feb 87-31 Jan 91,
Corporate Author : VANDERBILT UNIV NASHVILLE TN
Personal Author(s) : Haglund, Richard F., Jr. ; Tang, Kai ; Bunton, Patrick H. ; Wang, Ling-Jun
PDF Url : ADA302772
Report Date : OCT 1990
Pagination or Media Count : 14
Abstract : We present recent measurements of excited-atom and ion emission from KCl surfaces illuminated by vacuum-ultraviolet synchrotron radiation (hv = 8-28 eV) and ultraviolet laser light (hv = 4 eV). At low intensities characteristic of the synchrotron experiments, excited atoms are desorbed by simple valence-band excitation process involving the metallization of the KCl surface. At the higher intensities typical of laser desorption and ablation, we observe a strong decrease in K emission as a function of the number of laser shots, but an essentially constant yield of Cl*. K+ and Cl- emission at high intensities show similar behavior. The energetics of these desorption phenomena can be treated in a bond-orbital model which shows that creation of a single valence hole is sufficient to excite an ion to an anti-bonding state. jg p3
Descriptors : *ABLATION, *EXCITATION, *LASERS, *VALENCE BANDS, *POTASSIUM CHLORIDE, EMISSION, IONS, REPRINTS, HIGH RATE, ULTRAVIOLET RADIATION, DAMAGE, RESISTANCE, INTENSITY, VACUUM, OPTICAL MATERIALS, ATOMS, ATOMIC ORBITALS, CHEMICAL BONDS, ENERGETIC PROPERTIES, DESORPTION, ULTRAVIOLET LASERS, LOW INTENSITY, SYNCHROTRONS, METALLIZING.
Subject Categories : Inorganic Chemistry
Lasers and Masers
Atomic and Molecular Physics and Spectroscopy
Distribution Statement : APPROVED FOR PUBLIC RELEASE