Accurate Neutron Nucleus Reaction Measurement Instrument (ANNRI) for Capture Cross Section Measurements at J-PARC

作者：Kiyanagi Y^*

来源：Journal of the Korean Physical Society, 2011, 59(2): 779-784.

DOI：10.3938/jkps.59.779

• MLF
• ANNRI
• Minor actinides
• Long lived fission products
• Neutron capture cross section

A project promoting the nuclear data reserch has been executed. The major part of this project was to install a new beam line to measure the neutron capture cross sections of minor actinides (MAs) and longlived fission products (LLFPs) at the Materials and Life Science Experimental Facility (MLF) at J-PAR,C (japan Proton Accelerator Research Complex). The instrument completed is called as Accurate Neutron Nucleus Reaction measurement Instrument (ANNRI). The neutron source JSNS (japan Spallation Neutron Source) at MLF has been designed for 1 MW beam power. Such a high power is indispensable, since it enables us to obtain the high statistics data even for a very small amount of sample. For the measurements 4 pi Ge spectrometer with high energy resolution has been developed. We have prepared samples (244)Cm and (246)Cm as MA, and (99)Tc, (197)Pd, (93)Zr as LLFP. After the measurements of the neutron beam characteristics, capture cross section measurements have been performed on the MA and LLFP samples. The data on Cm isotopes are the first; one after the nuclear device experiment. ANNRI at 120 kW accelerator power level is already the highest neutron intensity facility for the capture cross section measurements in the world.

• 出版日期2011-8