Small Accelerators for Studies in the Application of Neutrons in Biomedicine

A small accelerator which produces high energy (14.7 MeV) neutrons by the H3 (H2, n) He4 reaction has been utilized for two basic biomedical studies. First, fast neutron radiography has been explored as a technique for imaging biological objects. The primary objective was to test the sensitivity of the technique by measuring the differential attenuation coefficient necessary for object identification as a function of the sample thickness. Second, fast neutron radiotherapy experiments were undertaken. Animals with induced brain tumors were treated to observe the relationship between dose fractionation and cell repair. The results are encouraging and indicate the feasibility of further studies with a small accelerator.