Composite CaWO4 Detectors for the CRESST-II Experiment
  CRESST-II, standing for Cryogenic Rare Events Search with Superconducting
Thermometers phase II, is an experiment searching for Dark Matter. In the LNGS
facility in Gran Sasso, Italy, a cryogenic detector setup is operated in order
to detect WIMPs by elastic scattering off nuclei, generating phononic lattice
excitations and scintillation light. The thermometers used in the experiment
consist of a tungsten thin-film structure evaporated onto the CaWO4 absorber
crystal. The process of evaporation causes a decrease in the scintillation
light output. This, together with the need of a big-scale detector production
for the upcoming EURECA experiment lead to investigations for producing
thermometers on smaller crystals which are glued onto the absorber crystal. In
our Run 31 we tested composite detectors for the first time in the Gran Sasso
setup. They seem to produce higher light yields as hoped and could provide an
additional time based discrimination mechanism for low light yield clamp
events.
