LUX-ZEPLIN

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.

Abstract:

We report on the development of an imaging cryogenic X-ray spectrometer based upon X-ray absorption in sapphire and readout by two tungsten superconducting phase transition thermometers (SPTs). We achieve one-dimensional imaging over an absorber length of 10 mm with a position resolution of approximate to 200 mu m. (C) 2000 Elsevier Science B.V. All rights reserved.

Abstract:

A theoretical model to describe the spectral response of SIS tunnel junctions under irradiation in the presence of diffusion and edge losses of non-equilibrium quasiparticles has been developed. The model takes into account the back-tunnelling effect, in the general case of asymmetrical rates of tunnelling, gamma(12) not equal gamma(21). It provides a quantitative estimate of parameters like the edge reflectivity, the diffusion length and the diffusion coefficient, which are important parameters for a diagnostic of STJ-detectors. The predictions of the theory are compared with an experimental spectrum obtained from a Nb-based STJ. (C) 2000 Elsevier Science B.V. All rights reserved.

Abstract:

We have developed a fast current readout system for STJ detectors with a fast current preamplifier by direct signal observation. The preamplifier has frequency bandwidth of 110 MHz with stable voltage bias operation. By the various experiments using a Ta STJ and Nb STJ, it is confirmed that the readout system is effective for the evaluation of STJs, research of the mechanism for signal production process and the X-ray detection with high counting rate. (C) 2000 Elsevier Science B.V. All rights reserved.

Abstract:

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.