10 research outputs found
Twelve-crystal prototype of LiMoO scintillating bolometers for CUPID and CROSS experiments
An array of twelve 0.28 kg lithium molybdate (LMO) low-temperature bolometers
equipped with 16 bolometric Ge light detectors, aiming at optimization of
detector structure for CROSS and CUPID double-beta decay experiments, was
constructed and tested in a low-background pulse-tube-based cryostat at the
Canfranc underground laboratory in Spain. Performance of the scintillating
bolometers was studied depending on the size of phonon NTD-Ge sensors glued to
both LMO and Ge absorbers, shape of the Ge light detectors (circular vs.
square, from two suppliers), in different light collection conditions (with and
without reflector, with aluminum coated LMO crystal surface). The scintillating
bolometer array was operated over 8 months in the low-background conditions
that allowed to probe a very low, Bq/kg, level of the LMO crystals
radioactive contamination by Th and Ra.Comment: Prepared for submission to JINST; 23 pages, 9 figures, and 4 table
A first test of CUPID prototypal light detectors with NTD-Ge sensors in a pulse-tube cryostat
CUPID is a next-generation bolometric experiment aiming at searching for
neutrinoless double-beta decay with ~250 kg of isotopic mass of Mo. It
will operate at 10 mK in a cryostat currently hosting a similar-scale
bolometric array for the CUORE experiment at the Gran Sasso National Laboratory
(Italy). CUPID will be based on large-volume scintillating bolometers
consisting of Mo-enriched LiMoO crystals, facing thin
Ge-wafer-based bolometric light detectors. In the CUPID design, the detector
structure is novel and needs to be validated. In particular, the CUORE cryostat
presents a high level of mechanical vibrations due to the use of pulse tubes
and the effect of vibrations on the detector performance must be investigated.
In this paper we report the first test of the CUPID-design bolometric light
detectors with NTD-Ge sensors in a dilution refrigerator equipped with a pulse
tube in an above-ground lab. Light detectors are characterized in terms of
sensitivity, energy resolution, pulse time constants, and noise power spectrum.
Despite the challenging noisy environment due to pulse-tube-induced vibrations,
we demonstrate that all the four tested light detectors comply with the CUPID
goal in terms of intrinsic energy resolution of 100 eV RMS baseline noise.
Indeed, we have measured 70--90 eV RMS for the four devices, which show an
excellent reproducibility. We have also obtained outstanding energy resolutions
at the 356 keV line from a Ba source with one light detector achieving
0.71(5) keV FWHM, which is -- to our knowledge -- the best ever obtained when
compared to detectors of any technology in this energy range.Comment: Prepared for submission to JINST; 16 pages, 7 figures, and 1 tabl
The Use of Artificial Benthic Collectors for Assessment of Spatial Patterns of Settlement of Megalopae of Carcinus maenas (L.) (Brachyura: Portunidae) in the Lower Mira Estuary, Portugal
Twelve-crystal prototype of Li2MoO4 scintillating bolometers for CUPID and CROSS experiments
An array of twelve 0.28 kg lithium molybdate (LMO) low-temperature bolometers equipped with 16 bolometric Ge light detectors, aiming at optimization of detector structure for CROSS and CUPID double-beta decay experiments, was constructed and tested in a low-background pulse-tube-based cryostat at the Canfranc underground laboratory in Spain. Performance of the scintillating bolometers was studied depending on the size of phonon NTD-Ge sensors glued to both LMO and Ge absorbers, shape of the Ge light detectors (circular vs. square, from two suppliers), in different light collection conditions (with and without reflector, with aluminum coated LMO crystal surface). The scintillating bolometer array was operated over 8 months in the low-background conditions that allowed to probe a very low, μBq/kg, level of the LMO crystals radioactive contamination by 228Th and 226Ra
Cross-validation of the behavioral and emotional rating scale-2 youth version: an exploration of strength-based latent traits
High-quality measurement is a necessary requirement to develop and evaluate the effectiveness of programs that use strength-based principles and strategies. Using independent cross-validation samples, we report two studies that explored the construct validity of the BERS-2 Youth Report, a popular measure designed to assess youth strengths, whose conceptual structure has not yet been examined. In Study 1, an exploratory factor analysis found a four-factor solution with conceptual support, which included both internal assets associated with (a) the management of emotions and positive social interaction skills and (b) engagement in the important social contexts of family and school. In Study 2, confirmatory factor analyses found reasonable model fit for the BERS-2 five-factor structure and superior model fit for the more parsimonious four-factor solution found in Study 1. In future studies, parallel reporting of the four-factor model may provide additional insight to the nature and structure of the BERS-2 Youth Version’s clinical validity and utility when compared with the five-factor model, thus potentially contributing to a broader objective to develop a better understanding of important strength-based latent traits
Search for Neutrinoless Decay of Te with CUORE
CUORE is a large scale cryogenic experiment searching for neutrinoless double beta decay () in Te. The CUORE detector is made of natural tellurium, providing the possibility of rare event searches on isotopes other than Te. In this work we describe a search for neutrinoless positron emitting electron capture () decay in Te with a total TeO exposure of 355.7 kg yr, corresponding to 0.2405 kg yr of Te. Albeit with two final state electrons represents the most promising channel, the emission of a positron and two 511-keV s make decay signature extremely clear. To fully exploit the potential offered by the detector modularity we include events with different topology and perform a simultaneous fit of five selected signal signatures. Using blinded data we extract a median exclusion sensitivity of yr at 90% Credibility Interval (C.I.). After unblinding we find no evidence of signal and set a 90% C.I. Bayesian lower limit of yr on Te half-life. This result improves by an order of magnitude the existing limit from the combined analysis of CUORE-0 and Cuoricino
Toward CUPID-1T
Current experiments to search for broken lepton-number symmetry through the observation of neutrinoless double-beta decay () provide the most stringent limits on the Majorana nature of neutrinos and the effective Majorana neutrino mass (). The next-generation experiments will focus on the sensitivity to the half-life of --~years and ~meV, which would provide complete coverage of the so-called Inverted Ordering region of the neutrino mass parameter space. By taking advantage of recent technological breakthroughs, new, future calorimetric experiments at the 1-ton scale can increase the sensitivity by at least another order of magnitude, exploring the large fraction of the parameter space that corresponds to the Normal neutrino mass ordering. In case of a discovery, such experiments could provide important insights toward a new understanding of the mechanism of . We present here a series of projects underway that will provide advancements in background reduction, cryogenic readout, and physics searches beyond , all moving toward the next-to-next generation CUPID-1T detector
Optimization of the first CUPID detector module
CUPID will be a next generation experiment searching for the neutrinoless double decay, whose discovery would establish the Majorana nature of the neutrino. Based on the experience achieved with the CUORE experiment, presently taking data at LNGS, CUPID aims to reach a background free environment by means of scintillating Li MoO crystals coupled to light detectors. Indeed, the simultaneous heat and light detection allows us to reject the dominant background of particles, as proven by the CUPID-0 and CUPID-Mo demonstrators. In this work we present the results of the first test of the CUPID baseline module. In particular, we propose a new optimized detector structure and light sensors design to enhance the engineering and the light collection, respectively. We characterized the heat detectors, achieving an energy resolution of (5.9 0.2) keV FWHM at the -value of Mo (about 3034 keV). We studied the light collection of the baseline CUPID design with respect to an alternative configuration which features gravity-assisted light detectors' mounting. In both cases we obtained an improvement in the light collection with respect to past measures and we validated the particle identification capability of the detector, which ensures an particle rejection higher than 99.9%, fully satisfying the requirements for CUPID
Status and prospects of discovery of 0νββ decay with the CUORE detector
International audienceIn this contribution we present the achievements of the CUOREexperiment so far. It is the first tonne-scale bolometric detector and it is in stabledata taking since 2018. We reached to collect about 1800 kg×yr of exposure ofwhich more than 1ton×year have been analysed. The CUORE detector is meantto search for the neutrinoless double ß decay (0.ßß) of the 130Te isotope. This isa beyond Standard Model process which could establish the nature of the neutrinoto be Dirac or a Majorana particle. It is an alternative mode of the two-neutrinosdouble ß decay, a rare decay which have been precisely measured by CUORE inthe 130Te. We found no evidence of the 0.ßß and we set a Bayesian lower limitof 2.2×1025yr on its half-life. The expertise achieved by CUORE set a milestonefor any future bolometric detector, including CUPID, which is the planned nextgeneration experiment searching for 0.ßß with scintillating bolometers