New method permits the detection of alpha emitters at a distance

A novel method is described that permits the detection of alpha-emitting materials, such as plutonium, at substantial distance. This method may permit the development of new instruments for monitoring equipment and personnel at entrances to facilities where alpha-emitting contaminants are a potential hazard. The technique uses detection of the secondary effects of alpha particles interacting in air (production of ions) to detect their presence. This technique is simple and requires no expensive equipment or exotic detectors. It is applicable to rapid automatic monitoring of personnel or equipment exiting hazardous areas. Experimental results obtained with this method are discussed