Fast Neutron Dosimetry by Means of Fission Foils

Two techniques are highlighted: (1) Neutron flux determination by distinct fission fragment absolute radiometric measurements on fission foils. The measuring technique and calibration procedure are discussed. Measuring results for the fission fragment escape from the fission foils (pure and alloys) are compared with calculations. Calibration results for 235U(nf) obtained at the French Masurca fast critical facility are presented in terms of fission chain yield measurements. The results are compared with ILRR (Interlaboratory LMFBR Reaction Rate program) and other fission yield complications. (2) Neutron flux determination by detection of the delayed neutrons emitted by a fissile sample. The measuring technique and calibration procedure are discussed. Results are given for 232Th(nf) and 238U(nf). A consistency check between calibration results for both reactions is presented in terms of total absolute delayed neutron yield and fission cross-section data.