The multiphoton ionization of uranium hexafluoride

Technical Report · Fri May 01 04:00:00 EDT 1992

DOI:https://doi.org/10.2172/5296034· OSTI ID:5296034

Armstrong, D. P. ^[1]

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1. Oak Ridge K-25 Site, TN (United States). UEO Enrichment Technical Operations Div.

Multiphoton ionization (MPI) time-of-flight mass spectroscopy and photoelectron spectroscopy studies of UF{sub 6} have been conducted using focused light from the Nd:YAG laser fundamental ({lambda}=1064 nm) and its harmonics ({lambda}=532, 355, or 266 nm), as well as other wavelengths provided by a tunable dye laser. The MPI mass spectra are dominated by the singly and multiply charged uranium ions rather than by the UF{sub x}{sup +} fragment ions even at the lowest laser power densities at which signal could be detected. The laser power dependence of U{sup n+} ions signals indicates that saturation can occur for many of the steps required for their ionization. In general, the doubly-charged uranium ion (U{sup 2+}) intensity is much greater than that of the singly-charged uranium ion (U{sup +}). For the case of the tunable dye laser experiments, the U{sup n+} (n = 1- 4) wavelength dependence is relatively unstructured and does not show observable resonance enhancement at known atomic uranium excitation wavelengths. The dominance of the U{sup 2+} ion and the absence or very small intensities of UF{sub x}{sup +} fragments, along with the unsaturated wavelength dependence, indicate that mechanisms may exist other than ionization of bare U atoms after the stepwise photodissociation of F atoms from the parent molecule.

• Research Organization: Oak Ridge K-25 Site, TN (United States). UEO Enrichment Technical Operations Div.; Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-84OT21400; AC05-76OR00001
• OSTI ID: 5296034
• Report Number(s): K/ETO-96-Rev.1; ON: DE92013383
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400702 -- Radiochemistry & Nuclear Chemistry-- Properties of Radioactive Materials
664400* -- Experimentally Derived Information on Atomic & Molecular Properties-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ACTINIDE COMPOUNDS
CHARGED PARTICLES
DISSOCIATION
DYE LASERS
ELECTRON SPECTROSCOPY
ENERGY LEVELS
EXCITED STATES
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
IONIZATION
IONS
LASERS
LIQUID LASERS
MASS SPECTROSCOPY
MEASURING INSTRUMENTS
MULTI-PHOTON PROCESSES
MULTICHARGED IONS
NEODYMIUM LASERS
PHOTOELECTRON SPECTROSCOPY
PHOTOIONIZATION
SOLID STATE LASERS
SPECTROMETERS
SPECTROSCOPY
TIME-OF-FLIGHT SPECTROMETERS
URANIUM COMPOUNDS
URANIUM FLUORIDES
URANIUM HEXAFLUORIDE