Total and Double Differential Scattering Cross-Section Measurements of Isotropic Graphite

The total and double differential scattering cross sections (DDSCS) of isotropic graphite have been measured in the J-PARC Materials and Life Science Experimental Facility using five samples with different porosities and grain sizes. The DDSCS measurements were performed in Beam Line No.14 (AMATERAS) with nine incident neutron energies ranging from 1.2 to 94 meV. In the derived cross sections, there are no clear sample dependence. The neutron total cross sections in the energy region from 1 to 100 meV were measured using Beam Line No. 04 (ANNRI). All samples in the epithermal range (over 40 meV) tended to have values close to the free atom cross-section of graphite. However, at the first Bragg edge, the deduced total cross sections by these measurements started to vary. The difference became more significant with decreasing the neutron energy.