Nanodosimetry of 125I – Auger electrons – Experiment and modeling

Abstract

The experiment with 125 I-Auger electrons, interacting with gaseous nitrogen with size equivalent to segment of DNA in mass per unit area scale, are described. The discrete ionization cluster-size distributions have been obtained. The shapes of which are definitely determined by the size of the interaction volumes. The volume sizes studied in the present work are comparable with a segment of DNA and of nucleosome. The experiments have been carried out with the set up, called Jet Counter, and are the first cluster-size distributions as yet measured for an Auger-electron emitter like 125 I. The experimental results have been compared with those obtained by Monte Carlo simulation. The results for 125 I have been compared with calculated cluster size distribution for 131 I. ► The results of nanodosimetric experiments using Auger electrons of 125 I are presented. ► The cluster distribution of radiation is the primary source of radiation damage. ► The new descriptors of electron interaction at the DNA level are defined.