The dosimetry of bone irradiated by fast neutrons

Abstract

The previous work on the dosimetry of bone is briefly reviewed. A dosimetric theory for the response of detectors irradiated by fast neutrons is applied to the problem of bone dosimetry. In the theory the detector of cavity shape is characterized by distributions of chord lengths along which the neutron-produced charged particles travel and deposit energy. Cavities of different convex geometries can be treated. A simplified version of the theory uses a single mean chord length to characterise the cavity. The absorbed dose to individual marrow cavities in trabecular bone is calculated over a large range of marrow cavity size for monoenergetic neutrons ranging from 0.5 to 7.0 MeV and for 252Cf neutrons. The influence of cavity shape is explored by considering spheres and cylinders of different elongation. The difference in adsorbed dose is not great. Also the simplified model using a single mean chord length gives results in close agreement with the results obtained with chord length distributions.