Experimental validation of thermal scattering evaluations

In order to test the performance of new neutron thermal scattering law (TSL) evaluations it is desirable have experimental data that highly sensitive TSL and provides high fidelity information on energy dependent evaluations. Three relevant experiments are discussed including: accurate total cross section measurements, die-away experiments, leakage experiments. The setups results reviewed examples provided for some moderators including polyethylene, Plexiglas, YHx. For preformed thus far, there generally good agreement between measured simulations using current evaluations, however in certain ranges differences were observed. Similarly measurements samples at room temperature with computed from TSLs, polyethylene 29K show discrepancies