Scientists heard their first pops this week in an experiment that searches for signs of dark matter in the form of tiny bubbles.
Stereoscopic view of the first COUPP-60 bubble at SNOLAB. Visible on the sides are the strings of piezoelectric sensors used to discriminate between alpha radioactivity and nuclear recoils like those expected from dark matter interactions.
COUPP-60 is a dark-matter experiment funded by DOE’s Office of Science. Fermilab managed the assembly and installation of the experiment’s detector. Leading the experiment is Juan Collar, associate professor in physics at the University of Chicago.
“Operation of COUPP-60 at SNOLAB is the culmination of a decade of work at the University of Chicago and Fermilab,” Collar said. “This device has the potential to become the most sensitive dark matter detector in the world, for both modes of interaction expected from Weakly Interacting Massive Particles.”
The COUPP-60 detector is a jar filled with 60 kilograms of purified water and CF3I—an ingredient found in fire extinguishers. The liquid in the detector is kept at a temperature and pressure slightly above the boiling point, but it requires an extra bit of energy to actually form a bubble. When a passing particle enters the detector and disturbs an atom in the clear liquid, it provides that energy.
Dark-matter particles, which scientists think rarely interact with other matter, should form individual bubbles in the COUPP-60 tank.
“The events are so rare, we’re looking for a couple of events per year,” Lippincott said.
Other, more common and interactive particles such as neutrons are more likely to leave a trail of multiple bubbles as they pass through.
Over the next few months, scientists will analyze the bubbles that form in their detector to test how well COUPP-60 is working and to determine whether they see signs of dark matter. One of the advantages of the detector is that it can be filled with a different liquid, if scientists decide they would like to alter their techniques.
“We are already working on a 500-kilogram chamber, to be installed in the same site starting in 2015,” Collar said.
The COUPP-60 detector is the latest addition to a suite of dark-matter experiments running at SNOLAB. Scientists run dark-matter experiments underground to shield them from a distracting background of other particles that constantly shower Earth from space. Dark-matter particles can move through the mile and a half of rock under which the laboratory is buried, whereas most other particles cannot.
Scientists further shield the COUPP-60 detector from neutrons and other particles by submersing it in 7,000 gallons of water.
Scientists first proposed the existence of dark matter in the 1930s, when they discovered that visible matter could not account for the rotational velocities of galaxies. Other evidence, such as gravitational lensing that distorts our view of faraway stars and our inability to explain how other galaxies hold together if not for the mass of dark matter, have improved scientists’ case. Astrophysicists think dark matter accounts for about a quarter of the matter and energy in the universe. But no one has conclusively observed dark-matter particles.
The COUPP (Chicagoland Observatory for Underground Particle Physics) experiment includes scientists, technicians and students from UChicago, Indiana University South Bend, Northwestern University, University of Valencia, Virginia Tech, Fermilab, Pacific Northwest National Laboratory and SNOLAB.
Steve Koppes | Newswise
Breakthrough with a chain of gold atoms
17.02.2017 | Universität Konstanz
New functional principle to generate the „third harmonic“
16.02.2017 | Laser Zentrum Hannover e.V.
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
20.02.2017 | Materials Sciences
20.02.2017 | Health and Medicine
20.02.2017 | Health and Medicine