Equivalentmass thermal motion model of neutron transport in water at different temperatures

In the Monte Carlo simulation, the S(,) model can only be used in some given temperature. The paper proposes the equivalent mass thermal motion model of neutron transport in water at different temperatures. The free gas thermal motion model is analyzed. Different equivalent masses are used to correct the neutron elastic scattering simulation of hydrogen in water, and the optimal equivalent mass of hydrogen in water at five different temperatures is given by comparing the result of the neutron flow through water layer with the S(,) model. According to the data of the five different temperature points, the formula of the optimal equivalent mass varying with temperature is fitted. The results of the equivalent mass thermal motion model are in accord with those of the S(,) model. The equivalent mass thermal motion model breaks the limitation of the S(,) model, and can deal with the neutron transport problems in water at arbitrary temperature between 300-800 K.