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.

A method which allows broadband optical detection of ultrasound with large étendue from a scattering surface is presented. The wave scattered by the surface interferes with a reference wave which is derived from the scattered wave after stripping it from its optical sidebands by a confocal resonator. Simple implementation by a confocal Fabry–Perot used in reflection is explained and demonstrated experimentally.

Silicon carbide is produced by a chemical reaction at high temperature between free crystalline silica and petroleum coke. The process generates airborne fibers and fibrogenic dusts such as alpha-quartz and cristobalite, which are also potentially carcinogenic. The authors report that this is the first cohort study in this industry. The study was carried out among 585 Québec silicon carbide production workers who had worked at any time from 1950 to 1980. Follow-up was to December 31, 1989, and 167 deaths were observed. The standardized mortality ratio (SMR) for all causes of death was 1.05 (95% confidence interval (CI) 0.90-1.23); for nonmalignant respiratory diseases it was 2.03 (95% CI 1.21-3.22); and for lung cancer it was 1.69 (95% CI 1.09-2.52). Controlling for smoking status using a Cox regression analysis, the risk for nonmalignant respiratory diseases and for lung cancer increased with exposure to total dust; in the highest exposure category, rate ratios (RR) were 4.08 (95% CI 1.11-14.96) for nonmalignant respiratory diseases and 1.67 (95% CI 0.57-4.83) for lung cancer. Results were in the expected direction, but the power of the study was low, because of small sample size and use of cumulative total dust as the exposure variable, which may be a poor indicator of lung irritants and other potential carcinogens in this industry, notably silicon carbide ceramic fibers.

The aim of the present work is to evaluate the potential of a fast growing laser technology, the fiber laser, in the field of laser-induced breakdown spectroscopy (LIBS). Many compact fiber lasers are now available, which produce a high quality beam and deliver sufficient energy to generate optically interesting plasmas for analytical purposes at very high repetition rates. This technology has not been yet seriously investigated for LIBS applications. We summarize here the main specifications and analytical performances of this laser source coupled to three different spectrometers for the analysis of aluminium samples. Limits of detection in the low mg g À1 range are calculated for magnesium, copper, manganese, silicon, iron and chromium. Using a compact spectrometer, a low limit of detection of 1.1 mg g À1 is obtained for magnesium in aluminium. Ablation craters produced on aluminium are also characterized. Finally, we briefly illustrate the possibilities of the fiber laser for the LIBS analysis of another matrix, calculating limits of detection that are below 20 mg g À1 for silver, iron and nickel in copper. Fig. 1 Conceptual representation of a master oscillator power amplifier.

This paper discusses the use of conventional LIBS and LIBS-LIF techniques for measuring trace amounts of palladium in solid ore samples. Combination of excitation/fluorescence of Pd lines as well as...