The proliferation of weapons of mass destruction and special nuclear materials is a serious threat in the world today. Preventing the spread of these materials and weapons is critical to our national security. The military, the Department of Homeland Security, and disaster site first responders require systems capable of detecting radioactive and other hazardous substances at very low concentrations and often at a significant distance. The ideal detector for security applications should have good energy resolution, high detection efficiency, compact size, light weight, easy portability, low power requirements and low cost. RMD is currently developing materials for Gamma-ray and neutron detection that will be important tools for maintaining control and checking for unauthorized movements of nuclear materials.