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Title: Analytical characterization of laser induced plasmas towards uranium isotopic analysis in gaseous uranium hexafluoride

Journal Article · · Spectrochimica Acta. Part B, Atomic Spectroscopy
 [1]; ORCiD logo [2]; ORCiD logo [2];  [3];  [1];  [4]
  1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); China University of Geosciences, Wuhan (China)
  4. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Applied Spectra, West Sacramento, CA (United States)

To perform direct enrichment assay on gaseous uranium hexafluoride (UF6) with laser induced breakdown spectroscopy (LIBS), the dominant spectral-line features, evolution of the signal and background of the U II 424.437 nm line, and its Stark width and shift, were studied as a function of UF6 gas pressure and pulse energy of a nanosecond Nd:YAG laser. In this work, vapor pressure of UF6 was found to be the most important parameter for LIBS analysis of gaseous UF6. Spectral congestion with numerous U lines of high excitation potential was observed and signal-to-background ratio (SBR) was low for measurements with 80 Torr UF6. Only when both UF6 vapor pressure and laser pulse energy were low, for example, less than 20 Torr pressure and 30 mJ pulse energy, the resultant LIBS spectra from gaseous UF6 resembled those obtained from solid U samples. The experimental data also suggest that U and F atoms recombine back to UF6 after the laser pulse. The U emission was found to decay fast with a persistent background signal, degrading SBR with delay time. Systematic positive biases were found for UF6 enrichment assays performed with the 235U–238U line pair at 424.412–424.437 nm, which was confirmed to be caused by self-absorption. Even with optimization of experimental parameters and incorporation of a self-absorption term into the spectral-fitting algorithm, to reduce and compensate for self-absorption, self-absorption is still a main factor limiting accurate UF6 enrichment assay. The use of another spectral window which contains no resonance lines is a prospective solution for the self-absorption issue.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation; China Scholarship Council (CSC)
Grant/Contract Number:
AC05-00OR22725; AC02-05CH11231
OSTI ID:
1775215
Alternate ID(s):
OSTI ID: 1841165; OSTI ID: 2325385
Journal Information:
Spectrochimica Acta. Part B, Atomic Spectroscopy, Vol. 176; ISSN 0584-8547
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

References (42)

The Absorption Spectrum of UF 6 , from 2000 to 4200 Å journal January 1975
Detection of BO2 isotopes using laser-induced breakdown spectroscopy journal December 2018
Spectroscopy and Structure of the Simplest Actinide Bonds journal October 2014
Study of UF 6 photodissociation through light scattering of UF 5 particles journal July 1980
Detection of Uranium Using Laser-Induced Breakdown Spectroscopy journal November 2009
Portable Spectroscopy journal September 2018
On the usefulness of a duplicating mirror to evaluate self-absorption effects in laser induced breakdown spectroscopy journal July 2009
Laser-induced breakdown self-reversal isotopic spectrometry for isotopic analysis of lithium journal June 2020
Study of low-temperature uranium plasmas not within local thermodynamical equilibrium journal December 1987
Isotopic analysis of uranium by laser induced breakdown spectroscopy journal May 2020
Mass-independent analysis of the stable isotopologues of gas-phase titanium monoxide – TiO journal January 2019
Mechanisms and efficient elimination approaches of self-absorption in LIBS journal January 2019
Laser photolysis of UF 6 molecules journal August 1999
Mapping of Uranium in Surrogate Nuclear Debris Using Laser-Induced Breakdown Spectroscopy (LIBS) journal March 2019
Moving your laboratories to the field – Advantages and limitations of the use of field portable instruments in environmental sample analysis journal July 2015
Matrix IR spectra of the products from fluorine molecule, chlorine molecule, and chlorine fluoride (ClF) reactions with pulsed-laser evaporated uranium atoms journal January 1994
A procedure for correcting self-absorption in calibration free-laser induced breakdown spectroscopy journal February 2002
Einstein coefficients, cross sections, f values, dipole moments, and all that journal November 1982
Polyhalide photofragment spectra. II. Ultraviolet photodissociation dynamics of UF 6 journal May 1978
Photolysis of uranium hexafluoride and some reaction variables affecting the apparent quantum yield journal January 1979
Measurement and analysis of the pure rotational spectra of tin monochloride, SnCl, using laser ablation equipped chirped pulse and cavity Fourier transform microwave spectroscopy journal October 2012
Role of elemental fluorine in nuclear field journal April 2007
Theoretical spectroscopy study of the low-lying electronic states of UX and UX+, X = F and Cl journal November 2015
A review of the current analytical approaches for evaluating, compensating and exploiting self-absorption in Laser Induced Breakdown Spectroscopy journal July 2020
Spectroscopic diagnostics of laser-induced plasmas journal August 2010
Multivariate determination of 10B isotopic ratio by laser-induced breakdown spectroscopy using multiple BO molecular emissions journal December 2019
Multivariate nonlinear spectral fitting for uranium isotopic analysis with laser-induced breakdown spectroscopy journal December 2018
Hydrogen isotopic analysis using molecular emission from laser-induced plasma on liquid and frozen water journal December 2019
Laser-induced breakdown spectroscopy of uranium in the vacuum ultraviolet range journal April 2020
A high-resolution laser ablation study of the transition of SrCCH journal October 2005
Field instrumentation in atomic spectroscopy journal November 2000
Emission spectroscopy of expanding laser-induced gaseous hydrogen–nitrogen plasma journal January 2017
Oscillator strengths for lines of ionized uranium (UII) journal May 1976
Measurements of Gaseous Hydrogen–Nitrogen Laser-Plasma journal June 2019
Fluorination of uranium dioxide particles: a review of physical and chemical properties of the compounds involved journal November 1999
The Spectrographic Determination of Uranium 235. Part IV. Using a Direct Reading, Littrow, Grating Spectrograph and a Hollow Cathode journal July 1961
Spectroscopic and Theoretical Investigations of UF and UF + journal February 2013
Evaluation of self-absorption coefficients of aluminum emission lines in laser-induced breakdown spectroscopy measurements journal December 2005
Reactions of Laser-Ablated U Atoms with HF: Infrared Spectra and Quantum Chemical Calculations of HUF, UH, and UF in Noble Gas Solids journal August 2014
A review of the development of portable laser induced breakdown spectroscopy and its applications journal November 2014
Optical spectroscopy of laser-produced plasmas for standoff isotopic analysis journal June 2018
The development of fieldable laser-induced breakdown spectrometer: No limits on the horizon journal December 2010