[Assesment of RBE of fast neutrons in Ehrlich ascites tumor cells by analysis of mitotic depression (author's transl)].

The depression of mitosis 1 hr following various doses of fast neutrons (6.2 Mev) and gamma rays was studied in an Ehrlich ascites carcinoma of mouse. Doses of 50, 100, 200 and 300 rad of either radiation yielded in the semilogarithmic plot a linear dose dependence of mitosis inhibition. From the regression straight line obtained the Relative Biological Effectiveness was determined, which declined from 2.8 at 50 rad to 1.8 at 300 rad neutron dose. The RBE is given analytically for the dose range investigated in dependence on neutron dose.