Modern tools for precise γ-ray spectrometry with Ge detectors

Over the past few years, several data evaluations and method developments have improved the capability to do precise γ-ray spectrometry and some of these are described here. For energy calibration, an evaluation of a large set of consistent γ-ray energies, generally with uncertainties of less than 10 ppm, has been published. A program to produce high-quality, well-documented decay data is the Decay Data Evaluation Project (DDEP) which is an informal collaboration of evaluators from six countries with the goal of producing evaluations of the decay data for about 250 nuclides of interest in various applications. As an aid in more precise efficiency calibration, new measurements have improved the relative emission probabilities for the strong γ rays from the decay of 56Co and 66Ga which extend up to 4.8 MeV. Also, new studies have demonstrated the use of Monte Carlo calculations along with measured data in the determination of efficiency curves at a precision approaching 0.1% over an extended energy range. A Catalogue of new γ-ray spectra, the associated decay schemes, and the energies and emission probabilities is being made available on the Internet.