Borexino : geo-neutrino measurement at Gran Sasso, Italy

Geo-neutrinos, electron anti-neutrinos produced in beta-decays of naturally occurring radioactive isotopes in the Earth, are a unique direct probe of our planet's interior. After a brief introduction of the geo-neutrinos' properties and of the main aims of their study, we discuss the features of a detector which has recently provided breakthrough achievements in the field, Borexino, a massive, calorimetric liquid scintillator detector installed at the underground Gran Sasso Laboratory. With its unprecedented radiopurity levels achieved in the core of the detection medium, it is the only experiment in operation able to study in real time solar neutrino interactions in the challenging sub-MeV energy region. Its superior technical properties allowed Borexino also to provide a clean detection of terrestrial neutrinos. Therefore, the description of the characteristics of the detected geo-neutrino signal and of the corresponding geological implications are the main core of the discussion contained in this work

Light Yield in DarkSide-10: a Prototype Two-phase Liquid Argon TPC for Dark Matter Searches

As part of the DarkSide program of direct dark matter searches using liquid argon TPCs, a prototype detector with an active volume containing 10 kg of liquid argon, DarkSide-10, was built and operated underground in the Gran Sasso National Laboratory in Italy. A critically important parameter for such devices is the scintillation light yield, as photon statistics limits the rejection of electron-recoil backgrounds by pulse shape discrimination. We have measured the light yield of DarkSide-10 using the readily-identifiable full-absorption peaks from gamma ray sources combined with single-photoelectron calibrations using low-occupancy laser pulses. For gamma lines of energies in the range 122-1275 keV, we get consistent light yields averaging 8.887+-0.003(stat)+-0.444(sys) p.e./keVee. With additional purification, the light yield measured at 511 keV increased to 9.142+-0.006(stat) p.e./keVee.Comment: 10 pages, 7 figures, Accepted for publication in Astroparticle Physic

Precision measurement of the reaction section of the inverse beta-decay of a neutron

The precision measurement of the reaction section of the inverse beta-decay of a neutron on the reactor of Rovno atomic power plant is the aim of the paper as well as the check of the standard model of the electroweak interaction. As a result the methodology of the precision measurement of the reaction section of the inverse beta-decay of a neutron has been developed. The new neutrino detector has been created. The reaction section has been measured with the least error in the world (1993)Available from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

DarkSide search for dark matter

The DarkSide staged program utilizes a two-phase time projection chamber (TPC) with liquid argon as the target material for the scattering of dark matter particles. Efficient background reduction is achieved using low radioactivity underground argon as well as several experimental handles such as pulse shape, ratio of ionization over scintillation signal, 3D event reconstruction, and active neutron and muon vetos. The DarkSide-10 prototype detector has proven high scintillation light yield, which is a particularly important parameter as it sets the energy threshold for the pulse shape discrimination technique. The DarkSide-50 detector system, currently in commissioning phase at the Gran Sasso Underground Laboratory, will reach a sensitivity to dark matter spin-independent scattering cross section of 10 cm within 3 years of operation

Borexino: Geo-neutrino measurement at Gran Sasso, Italy

Geo-neutrinos, electron anti-neutrinos produced in b-decays of naturally occurring radioactive isotopes in the Earth, are a unique direct probe of our planet\u2019s interior. After a brief introduction of the geo-neutrinos\u2019 properties and of the main aims of their study, we discuss the features of a detector which has recently provided breakthrough achievements in the field, Borexino, a massive, calorimetric liquid scintillator detector installed at the underground Gran Sasso Laboratory. With its unprecedented ra-diopurity levels achieved in the core of the detection medium, it is the only experiment in operation able to study in real time solar neutrino interactions in the challenging sub-MeV energy region. Its superior technical properties allowed Borexino also to provide a clean detection of terrestrial neutrinos. Therefore, the description of the characteristics of the detected geo-neutrino signal and of the corresponding geological implications are the main core of the discussion contained in this work

RESULTS FROM BOREXINO AT LNGS

The Borexino experiment is an ultra-pure liquid scintillator detector, running at Laboratori Nazionali del Gran Sasso (Italy). Borexino has completed the real time spectroscopy of the solar neutrinos generated in the proton-proton chain in the core of the Sun. This proceedings reviews the Borexino experiment and the first direct measurement of pp solar neutrinos

Study of the Rare Processes with the BOREXINO Detector

The status of the search for rare processes with the Borexino detector is reviewed. The discussed experimental results include searches for violation of the Pauli exclusion principle in nuclei, 5.5 MeV axions from p+d → ^3He+A reaction on the Sun and magnetic moments of solar neutrinos. New limits on the probability of non-Paulian transitions in ^12C nuclei [3], on the axion-electron, axion-photon and axion-nucleon coupling constants [4] and on the neutrino magnetic moments [2] are presented

DarkSide search for dark matter

"The DarkSide staged program utilizes a two-phase time projection chamber (TPC) with liquid argon as the target material for the scattering of dark matter particles. Efficient background reduction is achieved using low radioactivity underground argon as well as several experimental handles such as pulse shape, ratio of ionization over scintillation signal, 3D event reconstruction, and active neutron and muon vetos. The DarkSide-10 prototype detector has proven high scintillation light yield, which is a particularly important parameter as it sets the energy threshold for the pulse shape discrimination technique. The DarkSide-50 detector system, currently in commissioning phase at the Gran Sasso Underground Laboratory, will reach a sensitivity to dark matter spin-independent scattering cross section of 10(-45) cm(2) within 3 years of operation.