Results of the CRESST Commissioning Run 2007

Abstract

CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) is a lowtemperature experiment dedicated to the direct dark matter detection via nuclear recoil. It is located in Hall A of the Laboratori Nazionali del Gran Sasso, Italy. Scintillating CaWO4 crystals operated at a few mK are utilized as target forWIMPs (Weakly Interacting Massive Particles), which are expected to scatter predominantly on the heavy tungsten nuclei. As for background rejection, CRESST uses the phonon-light technique, where two different quantities of an interaction are recorded: the heat production in the CaWO4 crystal and the simultaneous emission of scintillation light, which is monitored by a second low-temperature detector, the light detector. The information provided by both detectors allows a powerful background discrimination on an event by event basis. After a major upgrade phase, CRESST-II has now successfully completed a commissioning run during 2007, the results of which are presented in this article.