Plasma sphere control for Accuracy improvement of Laser Induced Breakdown Spectroscopy

LIBS (Laser induced breakdown spectroscopy) has been introduced in an attempt to quantity the constituents of nuclear material in the homogeneously mixed solid sample which might be arisen from spent fuel processing facility. This type of analysis method has an advantage of real-time accountability of process material compared to time consuming chemical analysis for safeguards purpose and yet the measurement accuracy needed to be achieved seemed unsatisfactory due to the fluctuation of laser induced plasma sphere. This study is improves measurement accuracy by the carefully controlled plasma sphere. For the evaluation of measurement reproducibility the system was adjusted laser power and sample irradiation frequency against fixed position sample and rotating sample under the Air, Ar and He environment. Under the optimized measurement condition the preliminary experiment is being out quantitatively with simulated samples made of Nd, Gd of Lanthanum series element. Nd is a replacement element of U. In conclusion this experiment lead to potential of quantitative analysis of nuclear material contents in spent fuel handling process only if specific standards are on hand. The experiment will move forward to improve accuracy of quantitative measurement of sample of Nd, Sm, Gd with diversified mixture.