Indicator to estimate temperature sensitivity of resonance in temperature measurement by neutron resonance spectroscopy

摘要

Through series of simplification and simulation, we find that it is the ratio of z (=Ajr) and aa (cross-section at the exact resonance energy in the absence of temperature broadening) that contains the most information of temperature sensitivity for a resonance. We consequently define a factor h called the effective fitness indicator to represent the lower limit of temperature error for each resonance, h bears succinct forms and is tested against numerical simulations as well as gathered experimental data. Our further analysis and simulation justify the use of h at high temperatures (above several hundreds degrees centigrade). When the transmission of a resonance is free from suffering a flat-bottom (without ntσ_0 》 1), h can be used to estimate the temperature sensitivity of individual resonance with an analytic formula constructed from fitting, telling a relation between the temperature error and h. Moreover, spread of emission time caused by the moderator, phosphorescent decay of the scintillator, and background fraction are all included in numerical simulations to reveal their influences.