applicationContext = Production

The CRESST experiment

The search for dark matter

The CRESST experiment in the Gran Sasso underground laboratory
The CRESST experiment in the Gran Sasso underground laboratory (Photo: A. Eckert/MPP)

According to cosmological observations, ordinary matter, of which atoms, all living beings, stars, planets and galaxies consist, accounts for only 5 percent of the total matter in the universe. A larger portion by far, around 25 percent, is made up of so-called dark matter. It is, however, not yet clear what this consists of.

Our galaxy, the Milky Way, is surrounded by a large accumulation of dark matter. Its enormous mass has had a crucial impact on the evolution of the galaxy.

A number of well-founded theories state

  • that dark matter consists of particles that exert gravity and
  • interacts with visible matter - albeit very weakly.

If these dark matter particles exist, it should be possible to observe them from Earth with suitable measuring devices.

Scientists working on the CRESST experiment are on the lookout for dark matter. CRESST is an acronym for “Cryogenic Rare Event Search with Superconducting Thermometers”. The experiment is being conducted by a European research collaboration headed by the Max Planck Institute for Physics (MPP).

Tracking down dark matter with crystal detectors

Structure of the CRESST experiment, whose aim is to find dark matter particles.
Structure of the CRESST experiment, whose aim is to find dark matter particles. (Photo: A. Eckert)

The CRESST experiment is located in the underground laboratory below the Gran Sasso massif (Laboratori Nazionali del Gran Sasso, LNGS) in Italy. It comprises high-sensitivity detectors that react when a dark matter particle impinges on an atomic nucleus in the detector material.

Since a reaction between these particles and ordinary matter is an extremely rare event, researchers expect only a small number of observable events per year. In order to discover them with a high degree of certainty, the scientists have developed a special method.

The instruments consist of ultrapure, scintillating calcium tungstate crystals (CaWO4) whose operating temperature is at almost -273 degrees Celsius, i.e. close to absolute zero. When a dark matter particle collides with an atomic nucleus, the temperature in the crystal increases by around one millionth of a degree.

High-sensitivity sensors make all the difference

A detector of the CRESST experiment: The calcium tungstate crystal (bright block) is located inside a copper housing. The H-shaped temperature sensor is mounted on its surface. The sapphire-silicon platelet, which measures the light particles, is located on the right-hand side of the crystal.
A detector of the CRESST experiment: The calcium tungstate crystal (bright block) is located inside a copper housing. The H-shaped temperature sensor is mounted on its surface. The sapphire-silicon platelet, which measures the light particles, is located on the right-hand side of the crystal. (Photo: T. Dettlaff/MPP)

Highly sensitive thermometers in the detector measure this absolutely minute difference. In addition, the particle-particle interactions generate flashes of light in the crystal. The light particles – or photons, as they are known – are measured by a sapphire and silicon sensor.

The second signal has the important task of identifying which particle species has triggered the reaction. Signals caused by dark matter can thus be reliably distinguished from the radioactive background.

This technology is the basis for one of the most sensitive particle detectors ever built. In their search for dark matter, physicists can thereby venture into still unexplored mass regions. These properties make CRESST the top experiment in the search for particularly light particles of dark matter.

With its expertise in detector development, low-energy technology and data analysis, the MPP is playing a leading role in the CRESST research collaboration.

Further information on the CRESST group

News releases

03/29/2017

A change is announced in the CRESST scientific research group (Cryogenic Rare Event Search with Superconducting Thermometers) searching for dark matter. Federica Petricca, a scientist at the Max Planck Institute for Physics since 2005, succeeds Franz Pröbst. The longstanding head of the group...

Read more
09/29/2016

The CRESST experiment is continuing its search for dark matter. A few weeks ago, the detector reached its operating temperature of around -273 degrees Celsius, i.e. close to absolute zero. For the new measurement started in September, the experiment has been fundamentally overhauled: among other...

Read more
02/01/2016

Stefan Schönert, Professor for Experimental Astroparticle Physics at the Technical University of Munich (TUM), has been named a Max Planck Fellow at the MPP, where he will do research in the area of dark matter and neutrino physics. The Fellow Program of the Max Planck Society (MPG) has the goal of...

Read more
09/08/2015

Planets, stars, and galaxies form only the visible portion of the matter in the universe. Greater by far is the share accounted for by invisible "dark matter". Scientists have searched for the particles of dark matter in numerous experiments – so far, in vain. With the CRESST experiment, the search...

Read more

Group members

name function extension www

Abdelhameed, Ahmed

PhD Student 270

Angloher, Godehard, Dr.

Scientist 364

Bauer, Philipp

PhD Student 218

Bertoldo, Elia

PhD Student 473

Canonica, Lucia

Scientist 569

Ferreiro Iachellini, Nahuel

PhD Student 473

Hauff, Dieter

Scientist 266

Mancuso, Michele

Scientist 756

Petricca, Federica, Dr.

Scientist 309

Pröbst, Franz, Dr.

Scientist 270

Rothe, Johannes

PhD Student 218

Strauss, Raimund, Dr.

Scientist 237

Events

Currently, there are no events or meetings.

Key publications

Results on light dark matter particles with a low-threshold CRESST-II detector
G. Angloher et al. (CRESST Collaboration)
Eur. Phys. J. C 76, 25 (2016)

Limits on Momentum-Dependent Asymmetric Dark Matter with CRESST-II
G. Angloher et al. (CRESST Collaboration),
Phys. Rev. Lett. 117, 021303

Beta/gamma and alpha backgrounds in CRESST-II Phase 2
R. Strauss et al. (CRESST Collaboration)
J. Cosmol. Astropart. Phys. 06 (2015) 030

A detector module with highly efficient surface-alpha event rejection operated in CRESST-II Phase 2
R. Strauss et al. (CRESST Collaboration)
Eur. Phys. J. C (2015) 75:352

Results on low-mass WIMPs using an upgraded CRESST-II detector
G. Angloher et al. (CRESST Collaboration)
Eur. Phys. J. C 74, 3184 (2014)