Applicability of convex hull in multiple detector response space for neutron dose measurements

Hashimoto, Makoto  ; Iimoto, Takeshi*; Kosako, Toshiso*

A novel neutron dose measurement method which flexibly responds to variations of neutron field is being developed in JAEA. This is an implementation of the multi-detector method (first introduced in early 1970s) for neutron dose evaluation using convex hull in the response space defined for multiple detectors. The convex hull provides range of possible neutron dose corresponding to the incident neutron spectrum. Feasibility of the method was studied using simulated response of mixed-gas proportional counter. Monochromatic neutrons are shown to be fundamentally suitable for mapping the convex hull. The convex hull can be further reduced taking into consideration information about physically possible incident neutron spectra, for example, theoretically derived moderated neutron spectra originated from a fission neutron source.