Search

The CRESST experiment in its first phase is using sapphire detectors with tungsten phase transition thermometers to search for dark matter WIMPs. At present Four 262 g detectors are performing first measurements under low background conditions. Detector performance as well as preliminary results from the background runs are presented. A second phase of CRESST using CaWO4 and simultaneous measurement of phonons and scintillation light is in preparation. (C) 2000 Elsevier Science B.V. All rights reserved.

Results of the CRESST experiment at Gran Sasso using 262-g sapphire calorimeters with tungsten phase transition thermometers are presented. Calibration and analysis methods are described. Data taken in 2000 have been used to place limits on WIMP dark matter particles in the Galactic halo. The sapphire defectors are especially sensitive to low-mass WIMPs with spin-dependent interaction and improve on existing limits in this region. (C) 2003 MAIK "Nauka/Interperiodica".

Results of the CRESST experiment at Gran Sasso using 262 g sapphire calorimeters with tungsten phase transition thermometers are presented. Calibration and analysis methods are described. Data taken in 2000 have been used to place limits on WIMP dark matter particles in the galactic halo. The sapphire detectors are especially sensitive for low-mass WIMPS with spin-dependent interaction and improve on existing limits in this region.

Data taken by CRESST with a cryogenic detector system based on 262 g sapphire crystals has been used to place limits on WIMP dark matter in the Galactic Halo. The experiment was especially sensitive for low-mass WIMPs with spin-dependent cross sections and improves on existing limits in this region. © 2002 Elsevier Science B.V. All rights reserved.

The CRESST experiment seeks hypothetical WIMP particles that could account for the bulk of dark matter in the Universe. The detectors are cryogenic calorimeters in which WIMPs would scatter elastically on nuclei, releasing phonons. The first phase of the experiment has successfully deployed several 262 g sapphire devices in the Gran Sasso underground laboratories. A main source of background has been identified as microscopic mechanical fracturing of the crystals, and has been eliminated, improving the background rate by up to three orders of magnitude at low energies, leaving a rate close to one count per day per kg and per keV above 10 keV recoil energy. This background now appears to be dominated by radioactivity, and future CRESST scintillating calorimeters which simultaneously measure light and phonons will allow rejection of a great part of it., To appear in the proceedings of the CAPP2000 Conference, Verbier, Switzerland, July, 2000 (eds J. Garcia-Bellido, R. Durrer, and M. Shaposhnikov)

We present the current status of CRESST (Cryogenic Rare Event Search using Superconducting Thermometers) project and new results concerning detector development. The basic technique involved is to search for WIMPs by the measurement of non-thermal phonons, as created by WIMP-induced nuclear recoils. Combined with our newly developed method for the simultaneous measurement of scintillation light, strong background discrimination is possible, resulting in a substantial increase in WIMP detection sensitivity.

The CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) experiment at the Gran Sasso Laboratory will search for dark matter WIMPs using cryogenic detectors. In the first stage we will use four 262 g sapphire crystals with thresholds of about 0.5 keV. This low threshold gives us sensitivity to WIMP masses below 10 GeV, making CRESST complementary to other dark matter searches. The main installation in Gran Sasso is now complete and we report on the first detector tests.

Cryogenic detectors with excellent energy resolution and low energy threshold far beyond the level of semiconducting detectors open a variety of new. applications in physics including search for Dark Matter in the universe [2], neutrino physics [3], and IR-, UV- and X-ray astrophysics [4, 9]. Interdisciplinary fields where cryogenic detectors have already shown promising results are the detection of biomolecules [5] and X-ray spectroscopy at synchrotron beam lines [6] and in scanning electron microscopes (SEMs) [7]. For both, astrophysical and analytical use, the development of high resolution microcalorimeters based on iridium/gold phase transition thermometers and aluminum tunnel junctions for use in a compact and universal detector system was initiated.Our cryogenic microcalorimeters consist of an absorber, a temperature sensor and a weak coupling to a heat sink. An X-ray photon interacts with the absorber and raises its temperature. The sensor measures the temperature increase and the system then, mediated by the coupling, relaxes back to its operating temperature.