Abstract
NASBEE stand for Neutron Exposure Accelerator System for Biological Effect Experiment that had been settled at NIRS in 2004. The system consisted of two parts, inline type tandem accelerator with multi-cusp ion source (HVEE) and irradiation system (NEC Tokin). The system has dedicated to high flux neutron irradiation for biological specimens, especially Specific Pathogen Free (SPF) environment.
The system had a Nuclear and Industrial Safety Agency Nuclear and Industrial Safety Agency license in December 2005. At beginning of beam tuning, we suffered a lot of ion source problem, ex; filament terminal melt down etc. we set ion source current limitation up to 0.4mA at 4MeV beam energy for deuteron. The neutrons are produced from a water cooled 2mm beryllium target. Neutron irradiation experiments on a mouse an embryo and a rat mammary gland are conducting since March 2006. This report is intended to present an accelerator and maintenance troubles. We will also present up to date neutron biological experiments and neutron exposure filed measurements.
