Evaluation framework for search instruments

A framework for quantitatively evaluating current and proposed gamma-ray instruments intended for search applications has been developed. The framework is designed to generate a large library of "virtual neighborhoods" that can be used to assess the performance of nearly any gamma-ray sensor type (e.g. handhelds or Compton imagers). Calculating nuisance-source emissions and combining various sources to create a large number of random virtual scenes places a significant computational burden on the development of the framework. To reduce this burden, a number of radiation transport simplifications have been made which maintain the essential physics ingredients for the quantitative assessment of search instruments while significantly reducing computational times. The general approach to creating the evaluation framework and the simplifying transport assumptions employed to make it computationally tractable are discussed, and examples of how such a framework might be utilized by the national and homeland security communities are provided