Laser-induced breakdown spectroscopy has been applied to perform elemental analysis of aluminum alloy targets. The plasma is generated by focusing a pulsed Nd:YAG laser on the target in air at atmospheric pressure. Such a plasma was characterized in terms of its appearance, emission spectrum, space-integrated excitation temperature, and electron density. The electron density is inferred from the Stark broadening of the profiles of ionized aluminum lines. The temperature is obtained by using Boltzmann plots of the neutral iron lines. Calibration curves for magnesium, manganese, copper, and silicon were produced. The detection limits are element-dependent but are on the order of 10 ppm.

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Laser-Induced Breakdown Spectroscopy (LIBS) is currently a subject of great interest in spectroscopy and is being considered for the design of a field portable unit for nuclear safeguard inspection, because it allows a high level of portability and versatility while identifying the elements and materials of interest. Field portable technologies and methods are sought to provide simple, inexpensive, and fast analysis of materials in the mining, construction, and other industries. However, the level of portability needed for this particular application imposes some restrictions on the choice of many of the core components used in a low cost LIBS handheld sensor. This means that relatively low-performance components, such as a low-energy laser source and a low cost, low resolution spectrometer, must be considered to fulfil these conditions. In addition, the market price of such a portable device should be as low as possible to increase the breadth of potential end users and allow the deployment of multiple units for security enhancement. The present paper describes the determination of isotope ratios using Laser-Induced Breakdown Spectroscopy in air at atmospheric pressure for partially resolved uranium-235/ uranium-238 and hydrogen/deuterium isotope shift lines in such conditions. Using a Partial Least Square (PLS1) regression, it is possible to build a model that enables the accurate determination of the isotopic ratio under conditions where the application of traditional univariate approaches for hydrogen and uranium would not be achievable without the use of ultra high resolution spectrometer. In addition, the application of PLS1 regression to determine the uranium-235/uranium-238 and deuterium/hydrogen isotopic ratios between 0 and 1 mass fraction was also successfully demonstrated. The performance obtained with such a LIBS sensor configuration demonstrates the possibility of integrating all of the required components in a small portable handheld system.

The combination of laser-induced breakdown spectroscopy (LIBS) and laser-induced fluorescence (LIF) was investigated to improve the limit of detection (LoD) of trace elements in liquid water, while preserving the distinctive on-line monitoring capabilities of LIBS analysis. The influence of the main experimental parameters, namely the ablation fluence, the excitation fluence, and the inter-pulse delay was studied to maximize the fluorescence signal. The plasma was produced by a 266 nm frequencyquadrupled Q-switched Nd:YAG laser and the trace elements under investigation were then re-excited by a nanosecond optical parametric oscillator (OPO) laser, delivering pulses in the sub-mJ energy range, and tuned to strong absorption lines of the trace elements. The reproducibility of the measurements was improved using a home-made flow-cell, and relative standard deviations as low as 6.7% for a series of 100 shots were attained with a repetition rate of 0.7 Hz. Using the LIBS-LIF technique, we demonstrated LoDs of 39 ppb and 65 ppb for Pb and Fe, respectively, accumulating over 100 laser shots only, which correspond to an improvement of about 500 times with respect to LIBS.