Spatio-temporal evolution of uranium emission in laser-produced plasmas

S. S. Harilal, P. K. Diwakar, N. L. Lahaye, M. C. Phillips

Research output: Contribution to journalArticlepeer-review

30 Scopus citations


Abstract Laser-induced plasma spectroscopy provides much impetus as a nuclear forensics tool because of its capability of standoff detection and real-time analysis. However, special nuclear materials like U, Pu, etc. provide very crowded spectra and, when combined with shifts and broadening of spectral lines caused by ambient atmospheric operation, generate a complex plasma spectroscopy system. We explored the spatio-temporal evolution of excited U species in a laser ablation plume under various ambient pressure conditions. Plasmas were generated using 1064 nm, 6 ns pulses from a Nd:YAG laser on a U containing glass matrix target. The role of air ambient pressure on U line intensities, signal-to-background ratios, and linewidths were investigated. Spatially and temporally resolved optical time-of-flight emission spectroscopy of excited uranium atoms were used for studying the expansion hydrodynamics and the persistence of U species in the plume. Our results showed that U emission linewidths increased with pressure due to increased Stark broadening; however, the broadening was less than that for Ca. A comparison with U emission features in the presence of an inert gas showed the persistence of U species in plasmas in ambient air is significantly reduced; this could be due to oxide and other reactive species formation.

Original languageEnglish (US)
Article number4926
Pages (from-to)1-7
Number of pages7
JournalSpectrochimica Acta - Part B Atomic Spectroscopy
StatePublished - Jul 13 2015
Externally publishedYes


  • Ambient gas effects
  • LIBS
  • Line broadening
  • Nuclear forensics
  • U emission

ASJC Scopus subject areas

  • Analytical Chemistry
  • Atomic and Molecular Physics, and Optics
  • Instrumentation
  • Spectroscopy


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