The production of chromosome aberration in Chinese hamster fibroblasts exposed to 24 keV neutrons

A filtered reactor beam, consisting mainly of 24 keV neutrons, was used to study the induction of chromosome aberrations in the V79/4(AH1) Chinese hamster cell line. The yields of both dicentrics and acentrics were linear with dose and the value of relative biological effectiveness (RBE) for dicentrics at low doses was 6.5 + - 1.4. This value was similar to that found previously for a neutron spectrum with mean energy 2.1 MeV, and suggests that the RBE of neutrons does not increase to very high values in the energy region below 100 keV. This result does not support the suggestions of Davy (1969) and Key (1971) that the neutron RBE rises to very high values in the intermediate energy range. (author)