M. M. Hindi

Response function of a germanium detector to photon energies between 6 and 120 keV

Abstract We have developed a function to describe the response of an 8-cm3 germanium detector to photon energies as low as 6 keV, going up to 120 keV. Detection effects like the Ge X-ray escape and Compton scattered photons in the neighborhood of the detector were treated. This study was based on the fit of analytic functions to the features of the experimental spectra, thus revealing the parameters and their dependence on the photon energy. Our response function has 13 parameters and its validity is shown by the reproduction of the parameter-generating spectra and through the independent fit of an 152Eu spectrum.

Cosmic-ray history derived from the 54Mn, 56Ni and 144Pm chronometers

Sources of 54 Mn, 55 Ni, and 144 Pm were placed at the center of the Gammasphere array and searches were made for the astrophysically interesting β + decay modes of these isotopes. The results of these searches are presented and the implications for cosmic-ray physics are discussed.