In the Canadian underground physics laboratory SNOLAB, construction of the SuperCDMS installation has begun, designed to search for massive particles of dark matter. The new detector will be able to search for particles in the previously inaccessible range from one to ten proton masses, and the accuracy of SuperCDMS is 50 times higher than the accuracy of the previous version, making it one of the most sensitive detectors for the search for dark matter. The start of the construction of the detector is announced by the press release of the National Accelerator Laboratory SLAC, one of the project partners.
Dark matter makes up about 20 percent of the mass of the universe, but all the evidence for its existence, such as rotation curves of galaxies, gravitational lensing and measuring the rate of expansion of the universe, are gravitational in nature. At the same time, scientists have not yet been able to directly confirm the existence of dark matter particles. True, in 2010, the CDMS group reported the registration of one dark matter particle, but the statistical significance of this measurement was low, and later it was not confirmed.
Scientists do not lose hope and continue to improve experimental installations designed to register dark matter particles. In particular, the CDMS group reports on the construction of a new detector. A previous version of the setup they developed consisted of 30 semiconductor silicon-germanium detectors the size of a hockey puck, cooled to a temperature of about 0.6 kelvin, and was located at a depth of just under four hundred meters in an underground mine Sudan in Minnesota National Park to reduce the background signal from neutrinos and cosmic particles. When hypothetical massive dark matter particles (wimps) fly through such a washer, they can collide with the atoms of the crystal lattice and cause them to vibrate (such vibrations are conveniently described using quasiparticles - phonons); in addition, they can ionize matter,that is, knock electrons out of it. Both of these effects are easy to trace - the ionization signal can be read using amplifiers based on field effect transistors, and phonons can be conveniently captured using superconducting edge transition sensors based on superconducting quantum interferometers (SQUIDs). You can read more about such devices in our interview with Dmitry Akimov, dedicated to coherent elastic neutrino scattering, a process similar in nature and complexity.dedicated to coherent elastic neutrino scattering - a process similar in nature and complexity of registration.dedicated to coherent elastic neutrino scattering - a process similar in nature and complexity of registration.
Central part of the SuperCDMS detector. Greg Stewart / SLAC National Accelerator Laboratory.
