* Corresponding author. Fax #39-02-70609512. E-mail address: monica.sisti@mppmu.mpg.de (M. Sisti). Nuclear Instruments and Methods in Physics Research A 444 (2000) 312}314 The CRESST dark matter experiment: status and perspectives M. Sisti*, M. Bravin, M. Bruckmayer, C. Bucci, S. Cooper, P. Di Stefano, S. Giordano, F.v. Feilitzsch, T. Frank, J. Jochum, R. Keeling, H. Kraus, M. Loidl, J. Marchese, O. Meier, P. Meunier, U. Nagel, D. Pergolesi, F. Pro K bst, Y. Ramachers, J. Schnagl, W. Seidel, I. Sergeyev, L. Stodolsky, S. Uchaikin, L. Zerle Max-Planck-Institut fu ( r Physik, Fo ( hringer Ring 6, D-80805 Mu ( nchen, Germany University of Oxford, Department of Physics, Oxford OX1 3RH, UK Laboratori Nazionali del Gran Sasso, I-67010 Assergi (AQ), Italy Technische Universita ( t Mu ( nchen, D-85747 Garching, Germany Abstract The CRESST experiment in its "rst phase is using sapphire detectors with tungsten phase transition thermometers to search for dark matter WIMPs. At present four 262 g detectors are performing "rst measurements under low background conditions. Detector performance as well as preliminary results from the background runs are presented. A second phase of CRESST using CaWO  and simultaneous measurement of phonons and scintillation light is in preparation.  2000 Elsevier Science B.V. All rights reserved. 1. Introduction The goal of the CRESST (Cryogenic Rare Event Search using Superconducting Thermometers) ex- periment is the direct detection of dark matter WIMPs using cryogenic detectors. The devices de- veloped for this purpose consist of a dielectric crys- tal with a superconducting "lm evaporated onto its surface which acts as a very sensitive thermometer. In the "rst phase of CRESST we are using 262 g sapphire crystals as absorber material and tung- sten superconducting phase transition (SPT) thermometers (¹  &15 mK). In these detectors the dominant part of the signal arises from non-ther- mal phonons [1] and is independent of the heat capacity of the absorber: scaling up to large target masses is therefore feasible. The CRESST experi- ment is located in the Gran Sasso Underground Laboratory. A description of the apparatus is avail- able in Ref. [2]. After completing the installation of the experi- mental setup, a series of measurements have been carried out to optimize the detector performance. The extremely low energy threshold shown by the detectors and the light target nucleus with high spin (Al) make the present sapphire detectors parti- cularly sensitive to WIMPs with spin-dependent interactions in the mass region down to 1 GeV, beyond the reach of presently running experiments [4]. 0168-9002/00/$ - see front matter  2000 Elsevier Science B.V. All rights reserved. PII: S 0 1 6 8 - 9 0 0 2 ( 9 9 ) 0 1 4 0 5 - 9