Multiple -ray detection method and its application to nuclear chemistry

Oshima, Masumi; Toh, Yosuke   ; Hatsukawa, Yuichi; Koizumi, Mitsuo ; Kimura, Atsushi   ; Haraga, Tomoko   ; Ebihara, Mitsuru*; Sushida, Kazuyoshi*

It is well known that most radioactive nuclides emit coincident multiple -rays. The multiple -ray detection method takes advantage of this feature and the -rays are detected in coincidence with a -ray detector array. From the correlated data we can create a - two-dimensional matrix or -- three-dimensional cube. On this matrix or cube an energy resolution much better than the ordinary one-dimensional spectrum can be achieved. Furthermore signal-to-noise ratio is considerably improved. Hence this method can be applied widely to radioactive nuclide analysis. In the talk I will present its typical application to the analysis of nuclear waste, neutron activation analysis (NAAMG), and prompt -ray analysis (MPGA).