Shuichi Tsuda

Development of three kinds of tissue substitutes for a physical phantom in neutron dosimetry

Three kinds of tissue substitutes were synthesized in order to develop a physical phantom for neutron dosimetry. The optimal elemental compositions and densities were determined using a Monte Carlo simulation method, based on absorbed dose distributions of neutrons of a few MeV in various materials. The characteristics of the synthesized tissue substitutes were verified by absorbed dose measurements using monoenergetic neutron sources and a 252Cf neutron source. It was found that the developed tissue substitutes, NAN-, HAI- and HONE-JAERI, have tissue equivalence to actual tissues within an accuracy of 10% for neutrons in most of the common fast neutron fields.

Energy Dependence of Absorbed Dose Distributions In a Soft Tissue Substitute for Neutron Dosimetry

In order to develop a physical phantom for neutron dosimetry, a soft-tissue substitute improved in hydrogen and oxygen contents was synthesized. Absorbed dose distributions in the synthesized tissue substitute were measured using monoenergetic neutrons (0.556 and 5 MeV) and quasi-monoenergetic neutrons (40 and 65 MeV). It was found that the tissue substitute has soft-tissue characteristics in terms of the absorbed dose distribution, in the energy range from several MeV up to 100 MeV.