Development of delayed gamma-ray spectroscopy for nuclear safeguards, 2; Forward to a practical DGS instrument

Rossi, F. ; 小泉 光生 ; Rodriguez, D. ; 高橋 時音

Rossi, F.; Koizumi, Mitsuo; Rodriguez, D.; Takahashi, Tone

With the initial goal of fissile-nuclide content quantification in small samples containing uranium and plutonium, the Integrated Support Center for Nuclear Nonproliferation and Nuclear Security of the Japan Atomic Energy Agency is developing the Delayed Gamma-ray Spectroscopy non-destructive assay technique. For this, while in the past years several experiments were conducted to prove the feasibility of the technique, a new instrument was designed considering the previous lessons learned. It includes a modular insertion for different neutron sources, like radioisotopes or neutron generators; a gamma-ray detector with improved data acquisition system allowing for real-time dead-time correction; and a full new mechanism for the sample transfer between irradiation and measurement. Together with this, neutron detectors are integrated to supplement the DGS mass analysis and monitor the source intensity. In this work, we will describe the new instrument and the preliminary results obtained from instrument characterization compared to previous experiments. This work is supported by the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT) under the subsidy for the "promotion for strengthening nuclear security and the like". This work was done under the agreement between JAEA and EURATOM in the field of nuclear material safeguards research and development.