THE MEASUREMENT OF LEAKAGE NEUTRON SPECTRA FROM VARIOUS SPHERE PILES WITH 14 MeV NEUTRONS
Research Reactor Institute, Kyoto University
Kumatori-cho, Sennan-gun, Osaka 590-04, Japan
Junji Yamamoto, Mikio Izumi and Akito Takahashi
Dept. Nuclear Engineering., Fac. Engineering., Osaka University
Yamada-oka, Suita, Osaka 565, Japan
In order to check the existing nuclear data files such as ENDF/B-IV, JENDL-3 etc., neutron leakage spectra from various kinds of sphere piles have been measured using the intense pulsed neutron source at OKTAVIAN and time-of-flight techniques. Measured samples include LiF, TEFLON: (CF2)n, Si, Cr, Mn, Co, Cu, Nb, Mo and W. The thicknesses of the piles were 0.4 to 4.7 mean free paths for 14MeV neutrons. The obtained data were compared with the theoretical calculations using three kinds of transport codes, ANISN, NITRAN or MCNP and the evaluated nuclear data files, ENDF/B-IV, JENDL-3T and ENDL-73. ENDF/B-IV and ENDL-73 data contain several problems resulting considerably large disagreement in the spectra for LiF, TEFLON, Cr, Mn, Co, Cu, Nb, Mo and W, while JENDL-3T data gave preferable calculated spectra to the other data. Judging from the intercomparison between the measured and the predicted with JENDL-3T, it can be seen (1) satisfactory for Cu in whole energy range, (2) good for Si and Cr above 1 MeV and (3) good for Mn below 5 MeV but considerably large underprediction above this energy.
KEYWORDS: integral experiment, leakage spectrum, time-of-flight measurement, 14 MeV neutrons, liquid scintillator, transport calculation, ANISN, MCNP, NITRAN, evaluated nuclear date File, ENDF/B-IV, JENDL-3T, ENDL