Since neutron induced signals are very similar to dark matter induced signals, this new discovery, published today, Thursday, 16 October, in the New Journal of Physics, could lead to improved background suppression in dark matter searches with this type of detector.
So far, alpha particles have been an obstacle to the detection of dark matter’s weakly interacting massive particles (WIMPs) in PICASSO. This detector, which is based on the operation principle of the classic bubble chamber, is sensitive to alpha particles over exactly the same temperature and energy range, therefore making it very difficult to discriminate between the two types of particles.
Alpha particles are relatively common on Earth, emitted by radioactive nuclei such as uranium, and thorium, and are therefore also present in traces in the detector material itself. WIMPs are thought to fill the large spaces between galaxies, concentrating around them in gigantic clouds. As the Earth moves together with the sun through the Milky Way’s dark matter cloud, researchers hope to detect occasional collisions of a WIMP particle with an atom in their detectors.
Teams of researchers around the globe work deep underground to create the best conditions to isolate WIMPs from their travelling companions, namely neutrons, which are created by cosmic rays. Underground, teams in the US, Canada, England, Italy, Japan, Korea and Russia have long been sparring over the best detection methods for WIMPs.
The Canadian-American-Czech team based at SNOLAB, using their PICASSO detector, experimented with very sensitive Fluorine-based superheated liquids and analysed acoustic signals following phase transitions induced by alpha particles and WIMP like, neutron induced recoil nuclei. To their surprise they found a significant difference in amplitudes of the acoustic signals, which has never been observed before.
As experiment spokesperson Viktor Zacek (Université de Montréal) said, “When we looked at our calibration data taken with neutrons and compared them with our alpha background data we saw a peculiar difference which we attributed first to some detector instabilities or gain drifts in our electronics. However when we checked the data and refined the analysis the discrimination effect became even more pronounced.”
Detection of WIMPs is the first challenge in the struggle to understand dark matter. Much of our understanding until now has been hypothetical. There is convincing astronomical evidence to suggest that 23 per cent of the Universe is made up of dark matter – different from the matter with protons, neutrons and electrons that we are accustomed to.
This dark matter is between a hundred to a thousand times heavier than a proton and interacts extremely weakly with itself and ‘ordinary’ matter. It is believed it was created during the Big bang and that it now surrounds most galaxies, and also our Milky Way in gigantic clouds.
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Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.
The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
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In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
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