An approach based on the SIR measurement model for determining the ionization chamber efficiency curves, and a study of [formula omitted] and [formula omitted] photon emission intensities

Abstract

The measurement model used to determine ionization chamber efficiency curves accounts from the outset for impurity corrections and beta spectrum shapes. The curves are represented by exponentials of polynomials whose coefficients are adjusted using non-linear least-squares minimization. The curves are validated by comparing with SIR key comparison reference values (KCRVs) and other published curves. The associated covariance matrix is also evaluated. Deviations from model predictions for 65 Zn and 201 Tl using recommended nuclear data are studied.