Measurement of temperature-dependent thermal neutron spectrum in CaH2 moderator material for space reactor

Abstract

In order to accurately design a CaH2 moderated small high-temperature reactor, it is necessary to experimentally confirm the temperature-dependent thermal neutron spectrum in the CaH2 moderator material. To obtain the temperature-dependent thermal neutron spectrum in the CaH2, we have carried out the neutron scattering experiment using the TOF method at the Kyoto University Institute for Integrated Radiation and Nuclear Science - Linear Accelerator (KURNS-LINAC). In present experiment, we raised the temperature of the CaH2 from a room temperature 294 k to 392 K and 565 K, and obtained the change of the thermal neutron TOF spectrum for the increase of temperature. The obtained thermal neutron TOF spectra in the CaH2 are compared with the calculated results using the Monte-Carlo simulation code MCNP-6.2.