Cross Section Data and Kerma Coefficients at 95 MeV Neutrons for Medical Applications

摘要

Motivated by the need of data on neutron-induced reactions with biologically relevant materials, e.g., carbon and oxygen, we have constructed and installed the MEDLEY detector array at the neutron beam facility of the The Svedberg Laboratory in Uppsala. The central detection electrons of MEDLEY are three-detector telescopes, consisting of two silicon detectors and a CsI crystal. To cover wide energy and angle ranges, we have mounted eight such telescopes at 20° intervals. We have used ΔE - ΔE -E techniques to obtain good particle identification for protons, deuterons, tritons, ~3He and α particles over an energy range from a few MeV up to 100 MeV. To define the detector solid angle, plastic scintillators ere employed to serve as active collimators. We have up to now measured double-differential cross sections of inclusive light-ion production induced by 95 MeV neutrons on carbon and oxygen. From these data production cross sections, as well as partial kerma coefficients, are being determined. We have found that especially the proton kerma coefficient for carbon is substantially larger than that of a recent evaluation, leading to a large total kerma coefficient. The obtained data supports a trend observed for similar data at lower energies.