Year
2013
Abstract
Intercepting and identifying potentially dangerous radioactive materials and nuclear weapons is a high priority issue both for homeland security and for protecting our warfighters. In addition to locating radioactive sources, imaging can improve signal-to-noise ratio and provide higher sensitivity than discrete detectors. This can also reduce the frequency of false alarms since some legitimate sources and NORM can be readily identified as not being threats from the image. Thus, better nuclear imaging systems with both gamma-ray and neutron imaging capabilities would be of significant value for improved detection of such materials. To address this critical problem, RMD is investigating the design and construction of a portable gamma-ray/neutron imaging system based on RMD’s successful RadCamTM instrument. The instrument, which is based on the new generation of scintillator materials that have the capability to discriminate gamma rays from neutrons, will simultaneously image gamma rays and neutrons. Detecting and imaging neutrons provides the ability to detect sources that are heavily shielded for gamma rays. Since few materials emit neutrons, the presence of neutrons in the image is a strong indicator of the presence of fissile material. The system would also be useful for active interrogation. This paper will discuss camera design and examine the trade-offs needed to optimize both the gamma ray and neutrons imaging systems and present measured gamma and neutron images.