Abstract. 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. CRESST and the Dark Matter ProblemAfter a long period of development, cryogenic detectors are now coming on line and deliver significant results in particle-astrophysics and weak interactions. The goal of the CRESST project is the direct detection of elementary particle dark matter and the elucidation of its nature. Particle physics provides a well motivated dark matter candidate through the lightest supersymmetric (SUSY) particle, the 'neutralino' and one can find candidates in a wide mass range [1]. Generically, such particles are called WIMPS (Weakly Interacting Massive Particles). WIMPS are expected to interact with ordinary matter by elastic scattering on nuclei. Conventional methods for direct detection rely on the ionization or scintillation caused by the recoiling nucleus. This leads to limitations connected with the relatively high energy involved in producing electron-hole pairs. Cryogenic detectors use the much lower energy excitations, such as phonons. Since the principal physical effect of a WIMP nuclear recoil is the generation of phonons, cryogenic calorimeters are well suited for WIMP detection. Further, when this technology is combined with charge or light detection the resulting background suppression leads to a powerful technique to search for the rare nuclear recoils.The detectors developed by the CRESST collaboration consist of a dielectric target-crystal with a small superconducting film evaporated onto the surface. When this film is held at a temperature in the middle of its superconducting to normal conducting phase transition, it functions as a highly sensitive thermometer. The detectors presently employed in Gran Sasso use tungsten (W) films and sapphire (Al 2 O 3 ) absorbers, running near 15 mK. The technique can 2 J. Jochum CRESST collabroation also be applied to a variety of other materials. The small change in temperature of the superconducting film resulting from an energy deposit in the target leads to a relatively large change in the film's resistance. This change in resistance is measured with a SQUID. A small separate detector of the same type is used to see the light emitted when the target is a scintillating crystal. Present Status of CRESSTThe task set for the first stage of CRESST was to show the operation of four 262 g sapphire detectors, with a threshold of 500 eV under low background conditions. Meeting this goal involved the setting up of a low background, large volume, cryogenic installation and the development of massive, low background detectors with low ...

The World Stress Map (WSM) project has compiled a global database of quality-ranked data records on the contemporary tectonic stresses in the Earth's crust. The WSM 2005 database release contains approximately 16 000 data records from different types of stress indicators such as earthquake focal mechanisms solutions, well bore breakouts, hydraulic fracturing and overcoring measurements, as well as quaternary fault-slip data and volcanic alignments. To provide a software tool for database visualization, analysis and interpretation of stress data as well its integration with other data records, we developed the program CASMI. This public domain software tool for Unix-like operating systems enables the selection of stress data records from the WSM database according to location, data quality, type of stress indicator, and depth. Each selected data record is visualized by a symbol that represents the type of stress indicator and the orientation of the maximum horizontal compressive stress. Symbol size is proportional to the quality of the data record, and the colour indicates different tectonic regimes. Stress maps can be produced in different geographical projections and high-quality output formats. CASMI also allows the integration of user-defined stress data sets and a wide range of other data such as topography, Harvard centroid moment tensors, polygons, text data, and plate motion trajectories. CASMI, including the WSM 2005 database release, can be requested free of charge from the project's website at http://www.world-stress-map.org/casmi. We present two stress map examples generated with CASMI ranging from plate-wide to regional scale: (1) A stress map of central Europe, that reveals the correlation of stress field orientation and relative plate motion. (2) The fan-shape stress pattern in North Germany.

No abstract

No abstract

No abstract