Book Description

We have performed a number of experiments at LLNL recently to investigate the leakage of gamma rays from spheres of selected materials pulsed centrally with 14-MeV neutrons. Such spectral information may be carefully compared to calculational results to validate the transport models, particularly the nuclear cross section data base. In the present case, the TART code and SANDYL codes are used to explicitly calculate the observable, the recoil electron spectrum. The materials studied were H2O, 6LiD, Be, C, 14N, CF2, Al, Si, Ti, Fe, Cu, Ta, W, Au, Pb, Th, and 238U. Generally, agreement was good between experiment and calculation. However, for some, the calculations significantly underestimated or overestimated experiment. For oxygen (i.e., H2O), the ENDL cross section set led to a sizeable calculational overestimate. Re-examination led to a large improvement. For tungsten, the calculated output was approx. 30% below experiment. A re-evaluation led to closer agreement. 16 refs., 10 figs., 1 tab.