Corrections to the conventional approach to Si(Li) detector efficiency

摘要

The contribution to full-energy peak intensity from coherent or Compton scatter interactions followed by photoelectric absorption was calculated by the Monte Carlo method and found to be significant for photon energies above 30 keV. A multiple-event term was therefore incorporated in the conventional physical model of detector efficiency. Also, a widely used approximation in the model was made rigorous, thereby removing a source of error. Efficiency measurements with and without an external collimator suggested the need for a further additional term, this one describing incomplete collimation by the internal aperture structure. Measured efficiency curves were least-squares fitted using the conventional model with and without these corrections and new terms. The deduced detector thickness agreed with the manufacturer's value only when the new terms were used. Copyright (C) 2004 John Wiley Sons, Ltd.