Laser induced breakdown spectroscopy; Lanthanides; Quantitative analysis;RARE-EARTH-ELEMENTS; PLASMA-MASS SPECTROMETRY; NEUTRON-ACTIVATION ANALYSIS; QUANTITATIVE-ANALYSIS; AQUEOUS-SOLUTION; LIBS LIMIT; WASTE SALT; SAMPLES; OXIDE; WATER

Quantitative analysis of Pr, Nd, Ce, La and Sm were carried out simultaneously in LiF-KCl matrix using laser induced breakdown spectroscopic technique. Two non-interfering analytical emission lines have been identified for each lanthanide and using the internal standard method, the calibration curve is constructed from 0.3 to 5% for Pr, Nd, Ce and La and from 0.3 to 3% for Sm. Both the emission lines showed good regression coefficient ) ranging from 0.9953 to 0.9996. The analytical capability of this method is studied through the correlation uncertainty of measured values with its known value in synthetic samples containing all the lanthanides in equal amount . Low value of correlation uncertainty confirms that LIBS has a great potential for quantitative analysis of lanthanides in LiF-KCl matrix.

Optical isotopic analysis; Uranium; Laser ablation molecular isotopic spectrometry; Laser induced breakdown spectroscopy; Isotope shift;INDUCED BREAKDOWN SPECTROSCOPY; LEAST-SQUARES REGRESSION; EMISSION-SPECTROMETRY; QUANTITATIVE-ANALYSIS; ELECTRONIC-STRUCTURE; COMPUTER-SIMULATION; ENERGY-LEVELS; UO; FEMTOSECOND; RATIO

Through computer simulation on experimentally acquired optical spectra, uranium isotopic analysis by laser ablation molecular isotopic spectrometry and laserinduced breakdown spectroscopy were studied. The use of only one spectral feature, either the strong UO band at 593.55 nm or the nearby U I 593.382 nm line, are similar in precisions (similar to 1.5% in absolute U-235 abundances). Precision improves to 0.72% with the use of a group of U atomic lines from 591.6 to 596.5 nm. The use of both molecular bands and atomic lines further advances the precision to 0.42% and compares well with the U II 424.437 nm single-line benchmark (0.48% precision).

Laser-induced breakdown spectroscopy (LIBS); Microwave-assisted laser-induced breakdown spectroscopy (MA-LIBS); Effect of ambient gas; Analysis of Ca impurity in Gd2O3;INDUCED BREAKDOWN SPECTROSCOPY; ATOMIC EMISSION-SPECTROMETRY; URANIUM; ENHANCEMENT; IMPURITIES; EXTRACTION; ABLATION

The effect of ambient gas on measurements with microwave-assisted laser-induced plasma in microwave-assisted laser-induced breakdown spectroscopy(MA-LIBS) was studied with relevance for the analysis of nuclear fuel. A pelletized gadolinium oxide (Gd2O3) sample, which was used as a simulated nuclear fuel, was irradiated by a pulsed Nd:YAG laser (532 nm, 5 mJ) coupled with microwaves (2.45 GHz, 400 W) under various gases of air, Ar, and He. Microwaves can be effectively used to enhance laser-induced plasma emissions. The emission spectrums of Gd obtained by MA-LIBS in Ar and He gases are much better than those of the air case. Namely, the spectral lines can be clearly identified and are far from molecular bands. Furthermore, the emission intensity is highest with low background emissions. Linear calibration curves of Ca in the concentration range between 0 and 500 mg/kg as an impurity in Gd2O3 have been successfully obtained in all gases. The detection limits of Ca impurity in air, Ar and He gases were 2, 0.8 and 0.6 mg/kg, respectively, which are much lower than the required limits of Ca impurity in nuclear fuels.