Radio detection of UHE neutrinos with the antarctic impulsive transient antenna (ANITA) experiment: Instrumentation

29th International Cosmic Ray Conference, ICRC 2005 5 (2005) 415-418

Authors:

JT Link, SW Barwick, JJ Beatty, DW Besson, WR Binns, B Cai, JM Clem, A Connolly, PF Dowkontt, MA Duvernois, PA Evenson, D Goldstein, PW Gorham, CL Herbert, MH Israel, JG Learned, KM Liewer, ER Lusczek, S Matsuno, P Miocinovic, J Nam, CJ Naudet, RJ Nichol, KJ Palladino, M Rosen, D Saltzberg, D Seckel, A Silvestri, BT Stokes, GS Varner, D Williams, F Wu

Abstract:

ANITA is a balloon borne radio telescope designed to detect the interactions of ultra-high energy (UHE) neutrinos (> 3x1018 eV) in the Antarctic ice cap. These interactions produce Cherenkov radiation in the form of a distinct broadband radio pulse known as the Askaryan effect. The pure, radio transparent Antarctic ice cap serves as an almost ideal medium for the generation of these pulses and ANITA will have an effective viewing area of one million km2 at float altitude. A prototype experiment, ANITA-LITE was flown during the 2003/2004 Austral summer from Antarctica to do an impulsive RF background survey. We present a discussion of the instrumentation and technique we will use to utilize the ice cap as a detector to measure the UHE neutrino flux.

CRESST-II: dark matter search with scintillating absorbers

NUCL PHYS B-PROC SUP 138 (2005) 153-155

Authors:

G Angloher, C Bucci, C Cozzini, F von Feilitzsch, T Frank, D Hauff, S Henry, T Jagemann, J Jochum, H Kraus, B Majorovits, J Ninkovic, F Petricca, F Probst, Y Ramachers, W Rau, W Seidel, M Stark, S Uchaikin, L Stodolsky, H Wulandari

Abstract:

In the CRESST-II experiment, scintillating CaWO4 crystals are used as absorbers for direct WIMP (weakly interacting massive particles) detection. Nuclear recoils can be discriminated against electron recoils by measuring phonons and scintillation light simultaneously. The absorber crystal and the silicon light detector are read out by tungsten superconducting phase transition thermometers (W-SPTs). Results on the sensitivity of the phonon and the light channel, radiopurity, the scintillation properties of CaWO4 and on the WIMP sensitivity are presented.

CRESST II background discrimination: Detection of W-180 natural decay in a pure alpha-spectrum

(2005) 517-522

Authors:

C Cozzini, S Henry, H Kraus, B Majorovits, V Mikhailik, Y Ramachers, AJB Tohlrust, G Angloher, D Hauff, J Ninkovic, F Petricca, F Probst, W Seidel, L Stodolsky, C Bucci, F Von Feilitsch, T Jagemann, W Potzel, W Rau, M Razeti, M Stark, W Westphal, H Wulandari, J Jochum

Abstract:

For the first time the natural alpha decay of W-180 has been unambiguously detected in a (gamma, beta and neutron)-free background spectrum. This has been obtained by simultaneously measuring phonon and light signals with CRESST 11 cryogenic detectors. Results on the radio purity of the detectors and on the measured half-life of W-180 are presented.

Exploiting the materials signature in cryogenic WIMP detectors

(2005) 333-338

Authors:

H Kraus, VB Mikhailik, D Day, KB Hutton, J Telfer, Y Ramachers

Abstract:

The mass number dependence of the WIMP-nucleus scattering offers a method for identifying a true WIMP signal over a neutron background. In this paper we present a study on using a combination of ZnWO4 and CaWO4 absorbers to exploit this materials signature for WIMP detection. We show that already modest exposure in the region of 5 kg years should allow the detection of WIMP interaction for cross sections smaller than current experimental sensitivities. The combination of these two tungstates could form the basis of the first multi-target detector capable of WIMP identification through materials signature.

The CRESST dark matter search

(2005) 212-217

Authors:

B Majorovits, C Cozzini, S Henry, H Kraus, V Mikhailik, AJB Tolhurst, D Wahl, Y Ramachers, G Angloher, P Christ, D Hauff, J Ninkovic, F Petricca, F Probst, W Seidel, L Stodolsky, FV Feilitzsch, T Jagemann, W Potzel, M Razeti, W Rau, M Stark, W Westphal, H Wulandari, J Jochum, C Bucci

Abstract:

We present first competitive results on WIMP dark matter using the phonon-light-detection technique. A particularly strong limit for WIMPs with coherent scattering results from selecting a region of the phonon-light plane corresponding to tungsten recoils. The observed count rate in the neutron band is compatible with the rate expected from neutron background. CRESST is presently being upgraded with a 66 channel SQUID readout system, a neutron shield and a muon veto system. This results in a significant improvement in sensitivity.