The effect of neutron dose rate on jejunal crypt survival

The effect of dose rate of fast neutrons over a range from 0.02 Gy/min to 22.5 Gy/min on the survival of mouse jejunal crypts was investigated. A small but significant decrease in sensitivity with decrease in dose rate was observed. A 10-fold decrease in dose rate gave a decrease in effectiveness equivalent to 0.39 Gy. The sensitivity to changes in neutron dose rate is much smaller than the sensitivity to changes in dose rate of photons.