Long-range alpha detector (LRAD) for contamination monitoring

The authors describe a novel long-range alpha detector (LRAD) in which alpha particles interact with the ambient air, producing ionization in the air at the rate of about 30000 ion pairs per megaelectronvolt of alpha energy. These charges can be transported over significant distances (several meters) in a moving current of air generated by a small fan. An ion chamber located in front of the fan measures the current carried by the moving ions. The LRAD-based monitor is more sensitive and more thorough than conventional monitors. The authors present current LRAD sensitivity limits and results, practical monitor designs, and proposed uses for LRAD monitors.<
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