This Small Business Innovation Research (SBIR) Phase I project will develop a small, low-cost, digital, all solid state detector system containing a solid-state gamma-ray detector, a solid-state neutron detector, and a low power Si CMOS signal conditioning chip. These detectors will be combined with existing electronics component technology to create small radiation monitoring systems with visual readout and presettable audio alarm levels suitable for discrete site installation in strategic locations or for personal wear. The commercial application of this project will be to detect clandestine nuclear weapons and radioactive "dirty bombs". There is a need for such systems for use at strategic sites and for use by individuals such as dock workers, postal employees, private package transport personnel, and airport workers