Routine Surveys for Gamma-Ray Background Characterization

In gamma-ray spectroscopy and imaging, the natural gamma-ray background can significantly reduce detection sensitivity, especially when the source is weak and the background varies substantially. This project aims to systematically measure and characterize the spatial and temporal variations of the background in order to assess their impact on detection sensitivity and specificity for homeland security applications. An extensive survey of typical backgrounds found in the San Francisco bay area was performed, and initial measurement results are presented here.