Low temperature setup for quenching factor measurements of CaWO4 with neutrons

In the CRESST experiment, we are able to distinguish electron from nuclear recoils by the measurement of coincident phonon and scintillation light signals produced by an event in the CaWO4 crystals. At the TUM, experiments have been performed to determine the light output (quenching factor) caused by the different recoiling nuclei. Standard neutron sources have been applied as well as a monoenergetic pulsed neutron beam of the tandem accelerator at the Maier-Leibnitz-Laboratory in Garching. Measurements of the quenching factors at low temperature (mK) with a monoenergetic neutron beam are in preparation. The influence of the cryostat on the neutron beam has been investigated with a profile measurement. The results indicate that the cryostat filled with liquid helium does not change the beam profile significantly and causes only moderate background. (orig.)