Brown University | 2017 Nov 01
The proposed detector would use superfluid helium to explore mass ranges of dark matter particles thousands of times smaller than current large-scale experiments can detect.
[img3="A proposed dark matter detector using superfluid helium mightPhysicists from Brown University have devised a new strategy for directly detecting dark matter, the elusive material thought to account for the majority of matter in the universe.
detect particles with much lower mass than most current detectors.
Credit: Maris/Seidel/Stein/Brown University"]https://news.brown.edu/files/styles/hor ... k=nwkvlQCg[/img3][hr][/hr]
The new strategy, which is designed to detect interactions between dark matter particles and a tub of superfluid helium, would be sensitive to particles in a much lower mass range than is possible with any of the large-scale experiments run so far, the researchers say.
“Most of the large-scale dark matter searches so far have been looking for particles with a mass somewhere between 10 and 10,000 times the mass of a proton,” said Derek Stein, a physicist who co-authored the work with two of his Brown University colleagues, Humphrey Maris and George Seidel. “Below 10 proton masses, these experiments start to lose their sensitivity. What we want to do is extend sensitivity down in mass by three or four orders of magnitude and explore the possibility of dark matter particles that are much lighter.” ...
The detection strategy that the Brown researchers have come up with involves a tub of superfluid helium. The idea is that dark matter particles passing through the tub should, on very rare occasions, smack into the nucleus of a helium atom. That collision would produce phonons and rotons — tiny excitations roughly similar to sound waves — which propagate with no loss of kinetic energy inside the superfluid. When those excitations reach the surface of the fluid, they’ll cause helium atoms to be released into a vacuum space above the surface. The detection of those released atoms would be the signal that a dark matter interaction has taken place in the tub. ...
Dark Matter Detection Using Helium Evaporation and Field Ionization - Humphrey J. Maris, George M. Seidel, Derek Stein
- Physical Review Letters 119(18):1303 (01 Nov 2017) DOI: 10.1103/PhysRevLett.119.181303