Abstract
The autoradiography using ZnS (Ag) powder screen was studied for estimating the particle size of alphaemitting dust collected on an air sampling filter paper.
The sensitivities of three commercial emulsion films for the detection of plutonium particles were compared by using a ZnS (Ag) powder screen. The effect of particle size of ZnS (Ag) powder on the sensitivity was examined and also the change of apparent particle size distribution with exposure time was examined.
As the result the following were obtained;
1) The sensitivity of a polaroid film is about 10 times higher than that of the X ray films.
2) The minimum detectable activity for the polaroid film is 0.01 dpm for the exposure of 168 hours, which is equivalent to the diameter of 0.25μ for a 239PuO2 particle.
