The FNDS project aims at developing fission chambers to measure on-line the fast component of a high neutron flux (≈1014 ncm-2s-1 or more) with a significant thermal component. We identify with simulations the deposits of fission chambers that are best suited to this goal. We address the question of the evolution of the deposit by radiative capture and decay. A deposit of 242Pu appears as the best choice, with a high initial sensitivity to fast neutrons only slowly degrading under irradiation. The effect of unavoidable impurities was assessed: small concentrations of 241Pu and 243Pu can be tolerated.
|Journal||Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment|
|State||Published - 11 Aug 2008|