title: The r.b.e. of different energy neutrons as measured by the heamatopoietic spleen-colony technique.
abstract: The spleen-colony technique has been used for determining the relative biological effectiveness (r.b.e.) for several energies of neutron radiation. Donor mice were exposed for fission and accelerator-generated neutrons at a variety of doses and energies. Immediately after exposure, donor bone-marrow was removed from the hind legs, and standard amounts were injected intravenously into lethally X-irradiated recipients. After 7 days the recipients spleens were evaluated for surface colonies. Dose-response curves were obtained for each type of radiation and the Do was determined. The neutron r.b.e. values from the Do compared with 250kVp X-rays were: reactor 1.58, 252Cf 1:59, and accelerator varied from 2.85 at 1.0 Mev to 0.85 at 13.4 MeV.
mesh_terms: D000818:Animals; D002142:Californium; D004307:Dose-Response Relationship, Radiation; D005214:Fast Neutrons; D005720:Gamma Rays; D006412:Hematopoietic Stem Cells / Q000528:radiation effects; D008297:Male; D051379:Mice; D009502:Neutrons; D009680:Nuclear Fission; D011830:Radiation Effects; D011868:Radioisotopes; D013635:Tantalum; D014965:X-Rays
chemical_list: D011868:Radioisotopes; D013635:Tantalum; D002142:Californium