ON A HIGH-PURITY GE EDS DETECTOR .1. DETERMINATION OF DETECTOR EFFICIENCY

The absolute efficiency curve for an ultra-thin window (UTW) high-puri ty (intrinsic) germanium (HPGe) EDS detector was determined by compari ng EDS spectra from a set of standard specimens with spectra from the same compounds taken with a UTW Si(Li) detector, and with systematic c omputer simulations. The efficiencies of the two detectors are compara ble, except at energies between the Ge-L3 and Si-K absorption edges, w here the efficiency of the HPGe detector is approximately 20% lower. T he methodology employed allows important features of both detectors, p articularly their dead layer thicknesses, to be determined.