Particle Physics Seminar

Bolometric detectors were introduced in rare events physics in the 1980s. During the last 20 years these detectors became crucial for a large number of Neutrino Physics and Dark Matter search applications. A bolometer,
composed of an absorber crystal and a temperature sensor, measures the energy of an impinging particle converted into phonons. This provides us with an energy collection mechanism that is more efficient than those used in other standard detectors, which is translated into a much better energy resolution. Typical energy resolutions for kg scale bolometers are better than 2ä at 5.3 MeV and 1% at 10 keV, however the price to pay is a very slow time evolution of the signal. This good energy resolution together with the possibility of choosing a wide range of materials for the
absorber crystal, make bolometers the ideal candidates for a large number of rare events applications in which the slowness of the response is not important for the measurement. The CUORE experiment represents the present
challenge for the bolometric technique by pushing it from the present detector array size (tens of crystals with an effective mass of tens of kg) to the much larger detector number (~1000) and effective mass (~ton). Further improvements in sensitivity can be reached only reducing the background due to radioactive contaminations. The rejection of contaminations on the surface of faced materials is one of the crucial tasks. A scintillation-based approach for rejecting surface background is
presented and the innovative application of this technique in non-scintillating bolometric detectors is discussed.