LUX-ZEPLIN

Abstract:

Although it is well known that CaWO4 is a scintillator it is not often used. mainly because it has a slow light response. However, a high Z and a good light output make this crystal a candidate for use in direct dark matter search experiments. The Cryogenic Rare Event Search using Superconducting Thermometers (CRESST II) experiment looks. for hypothetical massive elementary particles called Weakly Interacting Massive Particles (WIMPs). In an elastic collision of WIMPs with ordinary matter a WIMP transfers part of its energy to a nucleus. Such nuclear recoils are the signals dark matter searches look for. CRESST is using CaWO4 crystals with coincident detection of phonons and scintillation light to suppress radioactive background. Light output and energy resolution of different CaWO4 samples were systematically measured. Best samples have an energy resolution at the Cs-137; line (661 keV) < 8%. As CRESST is a rare event search experiment it has to prevent the background caused by natural radioactivity; therefore, a study of the radiopurity of CaWO4 crystals has been performed. X-ray luminescence properties of crystal samples. in the temperature range 77-500 K, will be presented. (C) 2004 Published by Elsevier B.V.

Abstract:

Although it is well known that CaWO4 is a scintillator it is not often used, mainly because it has a slow light response. However, a high Z and a good light output make this crystal a candidate for use in direct dark matter search experiments. The Cryogenic Rare Event Search using Superconducting Thermometers (CRESST II) experiment looks for hypothetical massive elementary particles called Weakly Interacting Massive Particles (WIMPs). In an elastic collision of WIMPs with ordinary matter a WIMP transfers part of its energy to a nucleus. Such nuclear recoils are the signals dark matter searches look for. CRESST is using CaWO4 crystals with coincident detection of phonons and scintillation light to suppress radioactive background. Light output and energy resolution of different CaWO4 samples were systematically measured. Best samples have an energy resolution at the 137Cs line (661 keV)<8%. As CRESST is a rare event search experiment it has to prevent the background caused by natural radioactivity; therefore, a study of the radiopurity of CaWO4 crystals has been performed. X-ray luminescence properties of crystal samples, in the temperature range 77-500 K, will be presented. © 2004 Published by Elsevier B.V.

Abstract:

The CRESST Phase II experiment at Gran Sasso is using 300 g scintillating CaWO4 crystals as absorbers for direct WIMP (weakly interactive massive particles) detection. The phonon signal in the CaWO4 crystal is registered in coincidence with the light signal, which is measured with a separate cryogenic light detector. The absorber crystal and the silicon light detector are read out by tungsten superconducting phase transition thermometers (W-SPTs). As a result an active discrimination of the electron recoils against nuclear recoils is achieved. Results on the properties of the detector modules and on the WIMP sensitivity are presented. © 2005 Published by Elsevier B.V.

Abstract:

The inorganic scintillator is an important element of a new type of cryogenic phonon scintillation detectors (CPSD) developed for single particle detection. These detectors exhibiting superior energy resolution and ability to identify the type of interaction event are considered as a next generation instrumentation in the search for extremely rare events. The paper presents the latest results of our study on cryogenic scintillators thought for CPSD application in the search for dark matter. It gives a description of the concept of direct dark matter detection and the operation principles of GPSD. The paper envisages major materials requirements and summarises the results of the studies of luminescence and scintillation properties of tungstates (CaWO 4 and ZnWO4), molybdates (CaMoO4, MgMoO 4, and CdMoO4) and Ti-doped Al2O3 over a wide temperature range (9-300 K).

Abstract:

The ANITA experiment is a balloon-borne radio-pulse detector system designed to measure Ultra-High Energy (UHE) neutrinos interacting in the Antarctic ice utilizing the distinct broadband radio pulse due to the Askaryan effect. The radio-transparent ice serves as a target volume for the production of these pulses. ANITA will have an effective viewing area of over one million km2 of ice at float altitude (∼37 km). A prototype experiment, ANITA-LITE, was flown during the 2003-2004 Austral Summer from Antarctica to perform an impulsive RF background survey of Antarctica. In the process, it has yielded strong constraints on UHE neutrinos, ruling out some theoretical models. We also discuss the expected instrument performance for the first full ANITA flight, planned for a 2006 Austral Summer launch out of McMurdo, Antarctica.