Uranium isotope measurement by microwave-enhanced LIBS

Karino, Takahiro ; Akaoka, Katsuaki ; Oba, Hironori  ; Wakaida, Ikuo  ; Soriano, J. K.*; Ikeda, Yuji*

Measuring the composition of uranium isotopes in debris is important for the decommissioning of the Fukushima Daiichi Nuclear Power Station. Analysis of isotopes by laser induced breakdown spectroscopy (LIBS) requires a high-resolution spectrometer. However, the emission intensity becomes weaker when a high-resolution spectrometer is used. Therefore, we used microwave-enhanced LIBS for isotope measurements. Microwaves can improve spectral intensity. A microchip laser (Nd:YAG/Cr:YAG composite ceramics, wavelength: 1064 nm, laser energy: 1.0 mJ) was used in this experiment. The number of laser shots was 200 and the number of measurements was 5 for each sample. The microwave output at 2.45 GHz was 1000 W and the pulse length was 1.0 ms. We found out that the evaluation of uranium enrichment using microwave is better than without microwave.