Experimental investigation of neutrons penetrating through two-dimensional heterogeneous structure consisting of graphite and aluminum

An experimental study has been performed on neutron penetration in a two-dimensional heterogeneous structure consisting of graphite and aluminum. The results provide a basis for verification of the accuracy of two-dimensional shielding calculation codes. The experiments were performed at JRR-4 of JAERI and included measurements of the thermal neutron flux for five different arrangements of graphite and aluminum. Calculations were performed with a conventional procedure using the two-dimensional removal diffusion code, TRD-1. The calculated thermal neutron flux of TRD-1 agrees with the measured value within about 25%. (auth.)