On the Simultaneous Measurements of the Particle Size Distribution of Radioactive Charged Aerosols and Concentration Ratio of Positive to Negative (First Report)

A parallel plate type of mobility spectrometer provided with nuclear plates which are placed in a row in the middle area of collecting plates prior to sampling is examined for measuring the mobility spectra of radioactive charged aerosols. By this technique, it is able to record α ray tracks of radioactive substances collected on the surface of nuclear plates during and after sampling. In stored radioactive aerosols in a vessel carrying Rn decay products, RaA was often found clearly on the developed nuclear plate its star type α tracks with the mobility ranging from 3 cm2/v ⋅sec to 0.3 cm2/v ⋅sec.