2N2222A t r a n s i s t o r s were exposed i n various neutron f i e l d s ranging i n energy from thermal t o 14 MeV. Neu spectrun characterization data are reported f o r three f a s t reactors used i n hardness testing.The neutron energy dependence of t r a n s i s t o r damage response uas measured and compered u i t h predictions based on ASTM Standards and recent compilations of the s i l i c o n kerma factors calculated using NJOY.

Radiation transport calculations provide the backbone for the spectrum characterization used to support experimenters at research reactors. The radiation transport calculations provide a priori neutron spectra used in least squares spectrum adjustment. In addition, calculations are often the sole source of baseline neutron spectra data when an experimental test object substantially perturbs the free-field spectrum. It is crucial that analysts provide high fidelity uncertainty quantification for the spectrum calculations. This is an investigation of systematic trends as the distance to the source is varied in calculated spectra at a fast burst facility. A comparison of ratios is designed to highlight trends in the C/E ratios that may shed light on deficiencies in the transport cross sections or sensitivities to the details of the facility modeling. Initial comparisons of the latest IRDF-2002 [1] dosimetry cross section library to the SNL RML [2] cross section library have been made and are discussed.

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The feasibility and utility of calculating efficiency curves for HPGe detectors using the MCNP 4B transport code are explored. The calculated curves are compared to experimental data obtained from a 137Cs source counted on a HPGe detector. Efficiency data for the four centimeter reference location are reported in this work. The detector, shield, and counting fixtures are included in the model. This work also involved extensive sensitivity analyses. Sensitivity studies focused on seven parameters involving the active area of the germanium crystal. Three of the seven variables were found to be significant.

Experiments and calculations simulating the neutron shadow shield for a reactor-powered space vehicle are described, including calculations for a variety of shield configurations and materials, and an experimental benchmark test using a bare fast reactor.