Dosimetry Around Hot Particles with Microdosimetric Techniques

Abstract

Abstract After the Chernobyl accident small particles with high activities were detected on the ground. These 'hot particles' contained ß and ? emitters and sometimes a emitters. Two microdosimetric techniques have been tested, to determine experimentally the absorbed dose to tissue at distances between 2 µm and 40 µm from a 'hot particle'. With electric current measurements the dose as well as the dose mean lineal energy were determined. Traditional microdosimetric techniques also gave the single event distribution. The measurements were performed with a wall-less spherical proportional counter. The hot particle used contained only ß and ? emitters, therefore an a emitter was simulated with an a source. The dose distribution easily shows if a emitters are present. The results from the dose measurements and calculation agree within 50%. The measurements demonstrate that microdosimetric techniques are suitable for absorbed dose measurements around 'hot particles'.