Cresst

cresst web

 

Description

The CRESST (Cryogenic Rare Event Search using Superconducting Thermometers)  experiment is a search for WIMP dark matter particles via their elastic scattering off nuclei. The nuclei are in the absorber of a cryogenic detector, capable of detecting the small energy of the recoiling nucleus which has been hit by an incoming WIMP. Searching for very rare interactions with a low energy deposit involves two major aspects: a sensitive detector and a highly efficient suppression of backgrounds.
The cryogenic detectors developed by the CRESST collaboration are extremely sensitive and can measure the total energy deposited by an interacting particle. The detectors are run near 15 mK, in the middle of the W-film transition between its superconducting and normal states. Here a small change in the temperature of the superconducting film leads to a relatively large change in its resistance that we measure with a SQUID. To a good approximation, the high frequency phonons, created by a particle interaction or the absorption of light do not thermalize in the crystal until they are absorbed in the TES.  The high sensitivity of TES allows the CRESST detector to measure energy releases as low as 0.4 keV.
To achieve an efficient background discrimination, the detector modules developed for CRESST are based on scintillating CaWO4 crystals as absorbers. In these crystals a particle interaction produces mainly heat in the form of phonons, but in addition a small amount of the deposited energy is emitted as scintillation light. The amount of scintillation light depends on the type of the interacting particle. Therefore, when a second smaller calorimeter is added to detect this light, most common backgrounds can be eliminated through their light signal. CRESST detectors are thus extremely suitable for WIMP search, given their sensitivity and background rejection features. Moreover the different response to WIMP scattering of the different nuclei of which the absorber is composed (the light oxygen, the medium weight calcium and the heavy tungsten) makes CRESST a unique tool to prove a possible WIMP signal and, if confirmed, even to investigate WIMP properties in detail.
Here you can find an animation of the experiment in English, German or Italian.
 

 

Spokesperson
JLIB_HTML_CLOAKING (MPI München)
 
 

Collaboration

The CRESST collaboration combines about 40 physicists from six institutes. Information about these institutes and the individual CRESST groups is available through the following links:

Max-Planck-Institut für Physik - http://www.cresst.de/members.php

University of Oxford - http://www.physics.ox.ac.uk/users/kraus/research/

Technische Universität München - http://www.e15.ph.tum.de/

Universität Tübingen - http://www.pit.physik.uni-tuebingen.de/jochum/arbeitsgruppe.html

INFN Laboratori Nazionali del Gran Sasso - http://cresst.lngs.infn.it

Institut für Hochenergiephysik der Österreichischen Akademie der Wissenschaften Wien - http://www.hephy.at/en/research/projects/cressteureca/staff/

The experiment is located at the Gran Sasso underground facilities, hosted by the Laboratori Nazionali del Gran Sasso.

 

Recent publications

A complete list of our publications can be found on our official web page:
http://www.cresst.de/pubs.php

Recommended readings

Results about the surface-alpha event rejection of one detector module operated in CRESST-II phase 2 are available, see:
     R. Strauss et al.: A detector module with highly efficient surface-alpha event rejection operated in CRESST-II Phase 2 (2014)
     arXiv:1410.1753 [physics.ins-det]  http://arxiv.org/abs/1410.1753
 
First results on low mass WIMPs from one detector module of CRESST-II phase 2 (started in summer 2013) are available, see:
    G. Angloher et al.: Results on low mass WIMPs using an upgraded CRESST-II detector (2014)  
    EUR PHYS J C Volume 74, Number 12 (2014) http://link.springer.com/article/10.1140%2Fepjc%2Fs10052-014-3184-9
    arXiv:1407.3146 [astro-ph.CO] http://arxiv.org/abs/1407.3146 
 
Results from the investigation of the radiopurity of CaWO4 crystals using α events are available, see:
    A. Münster et al.: Radiopurity of CaWO4 Crystals for Direct Dark Matter Search with CRESST and EURECA, JCAP 2014, 018 (2014)
    http://iopscience.iop.org/1475-7516/2014/05/018/
    arXiv:1403.5114 [astro-ph.IM] http://arxiv.org/abs/1403.5114

Official website
http://www.cresst.de