Fiducial Volume of the Edelweiss Germanium Bolometers for Dark Matter Search Using Cosmogenic Activation

Abstract

In this work, we use 10.36 and 8.98 keV X-rays originating from the decay of Ge-68 and Zn-65 which are homogeneously produced in a Ge crystal in order to evaluate the fiducial volume of a 400 g coplanar grid HP-Ge bolometers in operation in the Edelweiss-II experiment. Different energy estimators are tested on the experimental data and a fiducial fraction of (39.9 +/- 5)% is found. The results are compared to simulations taking into account the anisotropy of the electron transport in Ge