A Comparative Study of Single-pulse and Double-pulse Laser-Induced Breakdown Spectroscopy with Uranium-containing...

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Materials Science

Background:

• Laser-induced breakdown spectroscopy (LIBS) is valuable for special nuclear material (SNM) sensing and nuclear forensics due to its speed, minimal sample prep, and stand-off capability.
• Uranium (U) detection using LIBS is challenging due to crowded emission spectra and difficulty discerning characteristic lines.
• Double-pulse LIBS (DPLIBS) is known to enhance analyte signal intensity over single-pulse LIBS (SPLIBS).

Purpose of the Study:

• To investigate and optimize the detection of uranium (U) signal in a glass matrix using double-pulse LIBS (DPLIBS).
• To compare the analytical performance of DPLIBS with conventional single-pulse LIBS (SPLIBS) for U detection.
• To explore plasma characteristics and identify mechanisms for signal enhancement in DPLIBS.

Main Methods:

• Utilized a double-pulse LIBS setup with a 1.06 µm Nd:YAG pre-pulse and a 10.6 µm TEA CO2 heating pulse in a near-collinear geometry.
• Identified characteristic emission lines for Calcium (Ca) and Uranium (U) in a glass matrix.
• Optimized experimental parameters, including inter-pulse delay and energy, for both DPLIBS and SPLIBS.

Main Results:

• DPLIBS demonstrated improved analytical merits for U detection compared to SPLIBS.
• Spatial and temporal coupling of the two pulses in DPLIBS enhanced signal intensity with minimal sample damage.
• Optimized plasma emission conditions and figures of merit for U lines were determined for both techniques.

Conclusions:

• DPLIBS offers significant advantages for detecting uranium in complex matrices like glass.
• The optimized DPLIBS technique provides enhanced sensitivity and analytical performance for SNM analysis.
• Understanding plasma dynamics is crucial for further improving LIBS-based SNM detection methods.