217 research outputs found
The MAJORANA 76Ge neutrino less double-beta decay project: A brief update
At present, MAJORANA is a research and development (R&D) project to
investigate the feasibility and cost of constructing and operating a one ton
decay experiment with ~1000 kg of Ge detectors fabricated from germanium
enriched to 86% in . The study will include three separate cryostats with
various types of detectors: un-segmented, un-segmented point-contact, minimally
segmented, and highly segmented. One cryostat will contain at least 30 kg of
enriched (preferably point-contact) detectors. The performance of the cryostats
and detectors as well as background levels will be investigated. The goal of
the demonstrator project is to reach a discovery sensitivity of ~ 1026 y.Comment: 3 pages, no figure
Calorimeter R&D for the SuperNEMO Double Beta Decay Experiment
SuperNEMO is a next-generation double beta decay experiment based on the
successful tracking plus calorimetry design approach of the NEMO3 experiment
currently running in the Laboratoire Souterrain de Modane (LSM). SuperNEMO can
study a range of isotopes, the baseline isotopes are 82Se and possibly 150Nd.
The total isotope mass will be 100-200 kg. A sensitivity to neutrinoless double
beta decay half-life greater than 10e26 years can be reached which gives access
to Majorana neutrino masses of 50-100 meV. One of the main challenges of the
SuperNEMO R&D is the development of the calorimeter with an unprecedented
energy resolution of 4% FWHM at 3 MeV (Qbb value of 82Se).Comment: Presented at 13th International Conference on Calorimetry in High
Energy Physics (CALOR08), Pavia, Italy, 26-30 May 200
Axion Detection via Atomic Excitations
The possibility of axion detection by observing axion induced atomic
excitations as recently suggested by Sikivie is discussed. The atom is cooled
at low temperature and it is chosen to posses three levels. The first is the
ground state, the second is completely empty chosen so that the energy
difference between the two is close to the axion mass. Under the spin induced
axion-electron interaction an electron is excited from the first to the second
level. The presence of such an electron there can be confirmed by exciting it
further via a proper tunable laser beam to a suitably chosen third level, which
is also empty, and lies at a higher excitation energy. From the observation of
its subsequent de-excitation one infers the presence of the axion. In addition
the presence of the axion can be inferred from the de-excitation of the second
level to the ground state. The system is in a magnetic field so that the
energies involved can be suitably adjusted. Reasonable axion absorption rates
have been obtained.Comment: 11 pages, six figures, 3 tables, more references adde
Results from the CUORE experiment
Neutrinoless double beta decay (0νββ) is a rare, second-order nuclear transition that occurs only if neutrinos are massive Majorana particles or through new physics beyond Standard Model. This process explicitly violates the lepton
number (L) by two units and, therefore, the observation of 0νββ would demonstrate that L is not a symmetry of nature. Combined with flavour mixing and cosmological measurements, it can provide unique contraints on neutrino mass scale and establish whether neutrinos are Dirac or Majorana particles. The Cryogenic Underground Observatory for Rare Events (CUORE) is an experiment located at the LNGS searching for 0νββ decay of 130Te. CUORE exploits the bolometric technique to reach high resolution around the Q-value (2527.5 keV). It consists of an array of 988 natural TeO2 cubic crystals grouped into 19 towers. With a total active mass of 742 kg (∼206 kg of 130Te), CUORE is operated at very low temperature with a new 3He/4He refrigerator. Data taking started at the beginning of 2017. After a
brief introduction on the detector and the way data analysis is performed, I describe CUORE first results for the search of the 0νββ decay that were published in March
2018
CUORE and CUORE-0 experiments
Neutrino oscillation experiments proved that neutrinos have mass and this enhanced the interest in neutrinoless double-beta decay (0νββ). The observation of this very rare hypothetical decay would prove the leptonic number violation and would give us indications about neutrinos mass hierarchy and absolute mass scale. CUORE (Cryogenic Underground Observatory for Rare Events) is an array of 988 crystals of TeO2, for a total sensitive mass of 741kg. Its goal is the observation of 0νββ of 130Te. The crystals, placed into the a dilution cryostat, are operated as bolometers at a temperature close to 10mK. CUORE commissioning phase has been concluded recently in Gran Sasso National Laboratory, Italy, and data taking is expected to start in spring 2017. If target background rate is reached (0.01counts/day/keV/kg), the sensibility of CUORE will be, in five years of data taking, T1/2 - 1026years (1σ CL). In order to test the quality of materials and optimize the construction procedures, the collaboration realized CUORE-0, that took data from spring of 2013 to summer 2015. Here, after a brief description of CUORE, I report its commissioning status and CUORE-0 results
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