Chromosome aberrations in human lymphocytes after irradiation with 15.0-MeV neutrons in vitro. II. Analysis of the number of absorption events and the interaction distance in the formation of dicentric chromosomes.

The rejoining distance for the formation of dicentric chromosomes in human lymphocytes after irradiation with 15.0-MeV neutrons has been derived on the basis of microdosimetric concepts. For the formation of a dicentric chromosome, primary lesions produced by absorption events can interact within the nucleus over a distance of at least I.8 mum. The mean number of absorption events within this range is lower than for sparsely ionizing radiation. The intercellular distribution of dicentric chromosomes is consistent with a negative binomial distribution.