GAMMA RAY SPECTROMETER FOR DETECTION AND AUTOMATIC IDENTIFICATION OF NUCLEAR MATERIALS

The design and development of a miniaturized gamma-ray spectrometer based on cell phone technology, is described. The system is intended for gamma-ray detection and automatic identification of nuclear materials and radioactive isotopes. The spectrometer uses cell phone technology to analyze the data and to distribute the results to security personnel. The spectrometer consists of two modules, detector module and wireless phone module. The pocket-size detector module houses a lanthanum halide detector along with a small data acquisition system and battery. Using a Bluetooth channel, this module communicates to the Motorola MPx220 phone with the custom data acquisition and analysis software (specially developed for this platform) which serves as data acquisition computer. It analyzes the accumulated spectrum on real-time basis and returns results to the screen of cell phone reporting the isotopic composition of detected radiation source and also evaluations of the source strength. The system has been programmed to mitigate or eliminate false alarms from medical isotopes and naturally occurring radioactive materials. The decision-making software can be “trained” to indicate specific signatures of radiation sources like SNM. Results are stored in time-stamped files in the memory of cell phone and can be transmitted to a remote computer database along with the image of the object under scrutiny to be analyzed by a remote subject matter expert. The cell phone can be also supplied with GPS tracker coupling radiological information with geographical coordinates. The sensor is designed for easy use and rapid deployment.