MEASUREMENT OF TOTAL NEUTRON CROSS SECTION FOR SOME ORGANIC MATERIALS IN THERMAL ENERGY REGIONCentury Research Center Corporation 3-6-2 Nihombashi, Hon-cho, Chuo-ku, Tokyo, Japan Nobuo Fukumura and Naruhito Aihara Power Reactor and Nuclear Fuel Development Corporation Narita-cho, Oarai-machi, Ibaraki-ken, Japan Otohiko Aizawa and Koichiro Hirano Atomic Energy Research Laboratory Musashi Institute of Technology Ozenji 971, Aso-ku, Kawasaki-shi, Japan The total cross sections of some organic moderators were measured for the thermal neutron energy range. The samples measured were normal dodecane, tri-butyl phosphate (TBP), and the mixture of 70 v/o of normal dodecane and 30 v/o of TBP which is typically used in a reprocessing plant. The cross section was measured as the transmission of thermal neutrons through samples using the chopper and T-O-F facility installed at the Musashi reactor TRIGA-II, (100 kW). It was found that although the measured cross section is almost the same for dodecane and TBP, they both show different behavior compared with that of water. We propose to use the new spectral densities to calculate the cross sections for the above moderators within the framework of Nelkin's formalism for water. KEYWORDS: total cross section, thermal neutron, dodecane, TBP, time-of-flight, chopper, TRIGA-II |