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

Abstract

Laser-induced breakdown spectroscopy (LIBS) holds potential advantages in special nuclear material (SNM) sensing and nuclear forensics, which require rapid analysis, minimal sample preparation, and stand-off distance capability. SNM, such as U, however, result in crowded emission spectra with LIBS, and characteristic emission lines are challenging to discern. It is well-known that double-pulse LIBS (DPLIBS) improves the signal intensity for analytes over conventional single-pulse LIBS (SPLIBS). This study investigates the U signal in a glass matrix using DPLIBS and compares it to signal obtained using SPLIBS. Double-pulse LIBS involves sequential firing of a 1.06 µm Nd:YAG pre-pulse and 10.6 µm TEA CO2 heating pulse in a near collinear geometry. Optimization of experimental parameters including inter-pulse delay and energy follows identification of characteristic lines for the bulk analyte Ca and the minor constituent analyte U for both DPLIBS and SPLIBS. Spatial and temporal coupling of the two pulses in the proposed DPLIBS technique yields improvements in analytical merits with a negligible increase in damage to the sample compared to SPLIBS. Subsequently, the study discusses optimum plasma emission conditions of U lines and relative figures of merit in both SPLIBS and DPLIBS. Investigation into plasma characteristics also addresses plausible mechanisms related to the observed U analyte signal variation between SPLIBS and DPLIBS.

Significance of ambient conditions in uranium absorption and emission features of laser ablation plasmas

“…Optical emission spectra act as fingerprints for specific plasma constituents. However, inherent disadvantages exist with LA-OES such as higher limits of detection in comparison to the other spectrometric techniques [16,17] and potentially detrimental matrix effects in multi-constituent targets [18]. Nevertheless, LA-OES is practical for numerous applications including nuclear forensics.…”

“…The electronic complexity of high-Z elements, or elements with high partition functions, such as U, generates congested spectra in which specific emission features are challenging to discern without high-resolution spectroscopic equipment [2,3,5,15,19,20]. Furthermore, samples may only contain trace amounts of U in a multiconstituent matrix, allowing emission features of more abundant target constituents to obfuscate those of U [13,18]. Consequently, further investigation into the practicality of LA-OES for usage in the nuclear forensics field is paramount.…”

Application of double-pulse laser-induced breakdown spectroscopy (DP-LIBS), Fourier transform infrared micro-spectroscopy and Raman microscopy for the characterization of copper-sulfides

“…These results are useful in the context of studies investigating how the m-LIBS will assist in the development of portable LIBS systems and improve the utility of this spectroscopy technique for eld applications. [63][64][65][66][67][68]…”

Study on spark discharge enhanced laser-induced breakdown spectroscopy of Fe particles in transformer oil

“…Approaches such as double pulse LIBS (DP-LIBS), 17,18 LIBS combined with laser-induced fluorescence (LIBS-LIF), 19,20 resonance enhanced LIBS (RELIBS), 21 and microwave assisted LIBS (MA-LIBS) 22 have been proven to be effective in sensitivity enhancement. However, their complicated optical systems or supporting transmission and coupling devices make the device larger and the operation process complicated.…”