Kerma associated with high energy neutrons

The kerma for monoenergetic neutrons of nominal energies 27, 42 and 63 MeV was measured with commercial tissue-equivalent and carbon proportional counters. By operating the detectors in helix mode and exposing them to pulsed beams of quasi-monoenergetic neutrons, time-of-flight (TOF) techniques enabled the unambiguous identification of pulse height events associated with the neutron energies of interest. The microdosimetric spectra so obtained were used to derive gas-to-wall dose conversion factors for the TE gas filled carbon proportional counter. Subsequently the kerma ratios for carbon to A-150 plastic at the three nominal neutron energies were determined with the monoenergetic data. The results concur with other published data using different techniques. (Author)