Application of Different Orthonormal Expansion Methods to Neutron Measurements. I. Analysis of Spectra

Abstract

This is the first of three papers. The following ones are entitled “II. Estimation of dose equivalent rates,” and “III. Actual measurements of spectra and dose equivalent rates,” respectively. Approximate neutron spectra can be obtained from the counting rates of BF3 proportional counters. The BF3 counters are covered with paraffin of different thicknesses. In the present work, the use of the meaningful orthonormal expansion methods is possible even when sensitivities of only modearte precision are used. The orthonormal sets of functions are constructed from the expected spectra as well as from the sensitivities of the detectors. The calculations using a digital computer show that the method employing the expected spectra is useful particularly when the number of employed detectors is small.