Precision Measurement of Relative γ-ray Energies with a Curved Crystal Diffractometer

Abstract

Very accurate energies of γ- and X-rays are needed as calibration lines for Ge(Li) work (1,2), for μ-onic and mesonic X- and γ-ray studies (3) and for theoretical work on heavy and super-heavy atoms (4). With the increasing performance of Ge(Li) spec­trometers the errors of several calibration lines became about as large as those of the measurement. However one would wish that in practically all cases the uncertainties of the standards were much smaller. A sufficiently precise set of γ-ray standards must therefore be measured with the use of another method. We have chosen a curved crystal spectrometer for the measurement of a set of relative γ-ray standards with 30 keV < E_r < 1.5 MeV and dE_r/E_r > 5.10⁻⁷ in relative energies based on the 411.794 ± 0 keV gold standard.