Enhancement of intensity in microwave-assisted laser-induced breakdown spectroscopy for remote analysis of nuclear fuel recycling

An enhancement of emission intensity from a laser ablation plume, obtained by coupling a pulsed microwave using a simple wire antenna, is demonstrated to compensate the sensitivity reduction of a high resolution spectrometer that is required for nuclear fuel analysis. A gadolinium oxide sample was irradiated with 2.45 GHz, 250 W microwave pulse, and passed through a loop antenna. As a result, up to 50-fold enhancement of the emission signal was achieved for gadolinium ions. The enhancement enabled us to measure the mass concentration of europium per gadolinium, ranging from 5% to 100 ppm, and based on the extrapolation of the calibration curve the detection limit for microwave-assisted laser induced breakdown spectroscopy (MA-LIBS) was estimated to be 40 ppm. This offers a flexible and compact system of MA-LIBS for nuclear fuel analysis.