[3H01-03] Experiment Technique

[3H02] Spectrum measurement of gamma ray from KUCA-C critical core

*Yasushi Nauchi¹, Tadafumi Sano², Hironobu Unesaki³, Yoshiyuki Takahashi³, kouji Kusumi¹, Junichi Hori³ (1. CRIEPI, 2. Kindai univ., 3. KURNS)

Keywords:critical core, gamma ray spectroscopy, HP-Ge, KUCA-C

Some of neuron induced reacions radiate gamma rays of their intrinsic spcra. Accordingly, we may know what kind of and how amount of nuclear reactoins occur in a system by way of gamma ray spectroscopy. However, such measurement have scarcely been perfrmed against critical core since the spectrum measuremen is unavilable under high count rate conditions. In KUCA-C core, we attained criticality with low power and confirmed it by a source region monitr located nearer to the core than usual position. Also, we put a HP-Ge detector which is shielded by neutron from the core by water layer of 60 cm in thickness. Thanks to those, the gamma-ray specrum of pulse -height region from 1 to 10 MeV was measured with god accuracy. We will report the spectrum and measured neutron flux and deduced neutron emission rate.