Physical conditions for UO formation in laser-produced uranium plumes
- BATTELLE (PACIFIC NW LAB)
- UNIVERSITY PROGRAMS
- UNIVERSITY OF MICHIGAN
- University of Michigan
Laser-induced plasma spectroscopy is a powerful method for elemental detection and analysis, however the broadening and merging of densely packed spectral lines can make it especially challenging for studying high-Z elements such as uranium and other actinides. In order to understand the processes occurring in laser-induced plasma, it is necessary to evaluate the variation of its thermodynamic parameters. We performed spatiotemporal diagnostics of uranium species in plasma plumes produced by nanosecond near-infrared laser pulses in low- pressure environment. Spatially- and temporally-resolved emission spectroscopy experiments are supported by modeling of uranium emission and its persistence in the plume. Saha-Eggert equation as well as Boltzmann diagrams generated from numerous U I transitions are used to infer temperature. We report the rst measurements of uranium Stark broadening parameters for U I 499.01 nm and U II 500.82 nm transitions. The Stark widths of selected U transitions were measured by comparing their linewidths with the broadening of O I 777.19 nm line. Electron density was found to be on the order of 1016 cm??3, while the temperature was found to be in the range of 3000{8000 K. In addition to enhancing the fundamental understanding of high-Z plasmas under reduced-pressure environments, the knowledge of Stark broadening parameters could improve modeling capabilities and analytical performance of techniques that rely on emission plasma spectroscopy.
- Research Organization:
- Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1601803
- Report Number(s):
- PNNL-SA-142809
- Journal Information:
- Physical Chemistry Chemical Physics. PCCP, Vol. 21, Issue 29
- Country of Publication:
- United States
- Language:
- English
Plume dynamics and gas-phase molecular formation in transient laser-produced uranium plasmas
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journal | August 2019 |
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