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astrolunch: Andrzej K. Drukier (OKC, Physics Dept., University of Stockholm) | The Racah Institute of Physics

astrolunch: Andrzej K. Drukier (OKC, Physics Dept., University of Stockholm)

Date: 
Sun, 28/01/201813:00-14:00
Ultimate DM detector
We disclose an implementation of RT-bolometers which comprise high chemical-energy materials, e.g. explosive or catalase, H2O2}-system, that can be operated at temperature between 4 oC and room temperature (RT). Energy deposited by the incident weakly interacting particle to the nuclei can trigger a local release of chemical energy;. The energy release in such a `nano-explosion’ indicates that a coherent scattering event has taken place and allows for the localization of this event;
For DM detection {catalase, H2O2}-system is preferred, and there are many catalases, which have maximum activity at temperatures from about 10 oC to about 90 oC. This permits to optimize enzymatic reactions and influences the read-out design. {catalase, H2O2}-system works because the range of recoiling nuclei is so short that most of the energy is transferred in a single “voxel” called “vertex”, leading to a large local temperature increase.
When neutrino or WIMPs scatter on nuclei, the majority of the recoil nucleus energy is transferred to the lattice, which leads to the creation of ballistic phonons which rapidly thermalize, i.e. increase the temperature in vertex. For 5 Gev/c2 < MDM < 15 GeV/c2 the energy of the recoiling nuclei is 0.5-2.0 keV and all this energy is deposited within a few nano-meters. Thus, the dE/dx = O(0.1 keV/nm) is deposited in the vertex. The energy deposition is much smaller in the case of single charged, relativistic particles and corresponds to dE/dx < 1 eV/nm for single charged particles. These permits backgrounds rejection.
We developed a very efficient read-out for such detectors The expected detector cost is low, ca. $50,000 per ton. The deployment will be deep underwater, say at Marina Trench at depth of 11 km. Optionally, such a detector can be used as a “spaghetti detector” and placed in very deep bore-holes down to 20 km water equivalent. Similar detectors can be used for Emission Geo-Neutrino Tomography aka Neutrino Geology.