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Khumaeni, A.; Tampo, Motonobu; Akaoka, Katsuaki; Miyabe, Masabumi; Wakaida, Ikuo
no journal, ,
A novel method for the analysis of nuclear elements such as uranium and plutonium in the next generation nuclear fuel cycle system was developed by utilizing microwave enhanced laser induced plasma spectroscopy (MELIPS). In this study, a Nd YAG laser was focused on a material target by using plano convex lens with a 200 mm focal length to induce a micro plasma. The plasma contains ablated material due to the ablation of the sample. The pulsed microwave generated by a magnetron through the antenna in the mesh chamber was then supplied to the micro plasma to enhance the plasma emission. The sample used in the study was gadolinium oxide pellet as a simulated fuel pellet. The result certified that the plasma lifetime was extent several hundreds of microsecond when the pulsed microwave was applied. The emission spectrum of Gd using standard LIPS (without microwave) was compared with MELIPS method. The spectrum of Gd was drastically enhanced by using MELIPS.
Oba, Hironori; Saeki, Morihisa; Wakaida, Ikuo; Tanabe, Rie*; Ito, Yoshiro*
no journal, ,
We applied single-pulse laser induced breakdown spectroscopy (LIBS) to liquid samples and evaluated detection sensitivity in both the liquid columnar flow and ultrathin sheet flow. The columnar flow of 0.52-mm diameter was prepared by a pipette-tip nozzle, whereas the ultrathin sheet flow with the thickness of 5
20
m was produced by a trapezoidal-shaped groove nozzle. The detection limits were estimated for alkali metal elements (Na, Rb, and Cs) under the optimum experimental condition. The detection limit of Na in an aqueous NaCl solution for the sheet flow is found to be 1.1 ppb, which is ten times lower compared to that for the columnar flow. The detection limits for Rb and Cs with the sheet flow were 7.1 ppb and 33 ppb, respectively. In this presentation, the feasibility of the LIBS measurement with the sheet flow for the simultaneous determination of elements in the mixed aqueous solution is also discussed.
Saeki, Morihisa; Iwanade, Akio; Ito, Chikara; Wakaida, Ikuo; Thornton, B.*; Sakka, Tetsuo*; Oba, Hironori
no journal, ,
To perform elemental analysis of solid samples under water and radiation field, we designed and constructed the instrument for fiber-coupled laser induced breakdown spectroscopy (LIBS). The LIBS analysis of the underwater sample is difficult, because the water quickly quenches the plasma plume that is generated by the ablation. To solve this problem, we prepared quasi-atmospheric condition around the plasma plume by using gas flow or double pulse irradiation system, and succeeded to observe similar spectrum between atmospheric and underwater condition. Moreover, the optical property of the fiber was investigated by exposing 
Co 
-ray with total dose over 1 MGy to the optic fiber. As a result, we found that radiation exposure to the fiber leads to slight damage in near infrared one. Thus, we designed the fiber-coupled LIBS system to perform laser ablation by near-infrared laser beam (1064 nm) and to efficiently detect plasma emission in near infrared region.