An instrument for personal dosimetry of radon daughters

The instrument described is intended for continuous measurement of the concentration of α-emitters in the uranium-238 decay chain (radon daughters and long-lived dusts) in suspension in air. It can be used to measure the concentration of aerosols of polonium-218 (radium A) and of polonium-214 (radium C'), and hence both the potential energy per unit volume, and the activity per unit volume of the long-lived α-emitters in suspended ore dust. A light-weight version, which can operate independently for 15 hours, is designed for measuring personal doses inhaled by workers in uranium mines and ore processing plants. There are two other versions with the same sampling head, one intended for monitoring the atmospheric concentration of α-emitters in work places, dwellings or the open air, and the other for uranium ore prospecting. (author)