Time-Resolved Femtosecond Laser Desorption from Alkali Halide Crystals.

Conference · Fri Oct 15 04:00:00 EDT 2004

OSTI ID:15011340

Joly, Alan G; Hess, Wayne P; Beck, Kenneth M; Phipps, Claude R

The positive ion yield as a function of delay between ultraviolet femtosecond pulse pairs for four alkali halide single crystals has been measured. Two-pulse correlation allows direct observation of solid state and surface dynamics on an ultrafast timescale. The ion yield from 265nm irradiated NaBr, KC1, KBr, and K1 depends critically on the time delay between the two sub-threshold pulses. Following irradiation of single crystal NaBr and KC1, the positive ion desorption yield displays three distinct features; a coherence peak, followed by rise, and decay features. In contrast, the yield of K+ from KBr displays only the coherence peak and picosecond decay features while the yield from K1 shows only the coherence feature. The data suggest that although the nanosecond ion desorption mechanism may be dominated by defect photoabsorption, significant electron-hole pair production may contribute to the desorption mechanism following femtosecond excitation.

• Research Organization: Pacific Northwest National Lab., Richland, WA (US), Environmental Molecular Sciences Laboratory (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 15011340
• Report Number(s): PNNL-SA-41296; 2214a; KC0301020
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ABLATION
CATIONS
DECAY
DEFECTS
DESORPTION
ENVIRONMENTAL MOLECULAR SCIENCES LABORATORY
EXCITATION
HALIDES
HYDROXIDES
IRRADIATION
LASERS
MONOCRYSTALS
PAIR PRODUCTION
TIME DELAY