Multiple astronomical observations have established that about 85% of the matter in the universe is not made of known particles. Deciphering the nature of this so-called Dark Matter is of fundamental importance to cosmology, astrophysics, and high-energy particle physics. A leading hypothesis is that it is comprised of Weakly Interacting Massive Particles, or WIMPs, that were produced moments after the Big Bang. If WIMPs are the dark matter, then their presence in our galaxy may be detectable via scattering from atomic nuclei in detectors located deep underground to help reject backgrounds due to cosmic rays.
The Cryogenic Dark Matter Search (CDMS) Collaboration has pioneered the use of low temperature phonon-mediated detectors to detect the rare scattering of WIMPs on nuclei and distinguish them from backgrounds. This work will have a broad impact which extends beyond a dark matter search. The technical developments will further advance phonon-mediated detectors, which have already found many applications in science and technology.
This award will provide support for the design and fabrication of a next-generation (G2) experiment, SuperCDMS SNOLAB, which will operate at the deepest large clean underground laboratory in the world. The high background rejection and control of contamination that the SuperCDMS technology offers provide significant advantages compared to other technologies. The baseline design for this new experiment will deploy an initial 50 kg payload of germanium (Ge) and silicon (Si) detectors. Some of these detectors will be operated in a manner that provides very low energy thresholds and thus world-leading sensitivity to the lowest dark matter particle masses (< 0.5 GeV) and multiple-target complementarity in a single experiment. It will provide a strong possibility of the discovery of particle dark matter and detailed information on its properties.
This award will also contribute to the training of undergraduate and graduate students and postdoctoral researchers, using techniques at the leading edge of measurement technologies. SuperCDMS scientists will continue their involvement in public outreach, collaboration with K-12 teachers, and support for Berkeley physics majors who are training to teach science and for promising high school students from underserved backgrounds.
