745 research outputs found

    Status of the CUORE and CUORE-0 experiments at Gran Sasso

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    CUORE is a 741 kg array of TeO2 bolometers for the search of neutrinoless double beta decay in 130Te. The detector is being constructed at the Laboratori Nazionali del Gran Sasso, Italy, where it will start taking data in 2015. If the target background of 0.01 counts/(keV·kg·y) will be reached, in five years of data taking CUORE will have a half life sensitivity of ∼ 1026 y. CUORE-0 is a smaller experiment constructed to test and demonstrate the performances expected for CUORE. The detector is a single tower of 52 CUORE-like bolometers that started taking data in spring 2013. The status and perspectives of the CUORE and CUORE-0 experiments will be presented

    Focal Cerebral Infarction in Newborn: Description of Three Cases:

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    We observed 3 full-term newborns with focal ischemic injury of the middle cerebral artery (MCA), in which diagnosis of MCA stroke was suspected by US and confirmed by CT scan and MRI. A four-year follow-up was carried out to study the effect of neonatal stroke on neurodevelopmental outcome. All children had a history of pre-perinatal risk factors: neonatal cerebral infarction in term infants, in fact, has many possible causes, including bacterial meningitis, inherited or acquired coagulopathies, trauma and hypoxia-ischemia. The prognosis of neonatal MCA infarction depends on early diagnosis, on the CNS plasticity mechanism and, finally, on medical therapy and neuropsychological rehabilitation

    Weight management, psychological distress and binge eating in obesity. A reappraisal of the problem

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    The psychological effects of dieting and weight loss have been an area of controversy in obesity. As part of a large multicenter study involving 1944 obese subjects seeking treatment at Italian medical centers, we investigated the effects of weight loss on psychological distress and binge eating in 500 subjects remaining in continuous treatment at different centers with slightly different strategies (78.8% females; age: M = 46.2 years, SD = 10.8; BMI: M = 37.3 kg/m2, SD = 5.6). At baseline and after 12 months all subjects were evaluated by the SymptomCheckList-90 Global Severity Index (SCL-GSI) and by the Binge Eating Scale (BES). In both males and females, weight loss was associated with improved psychometric testing. Changes in SCL-GSI were associated with changes in BMI (b = 0.13; t = 2.85; p < 0.005), after adjustment for age, gender, initial BMI and center variability. Similarly, BES changes were associated with BMI change (b = 0.15; t = 3.21; p < 0.001). We conclude that in subjects compliant to follow-up a successful management of obesity, not directly addressing psychological distress, is associated with a significant improvement of both psychological distress and binge eating, linearly related to the amount of weight loss, independently of treatment procedures

    Characterization of the KID-Based Light Detectors of CALDER

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    The aim of the Cryogenic wide-Area Light Detectors with Excellent Resolution (CALDER) project is the development of light detectors with active area of 5×55\times5 cm2^2 and noise energy resolution smaller than 20 eV RMS, implementing phonon-mediated kinetic inductance detectors. The detectors are developed to improve the background suppression in large-mass bolometric experiments such as CUORE, via the double read-out of the light and the heat released by particles interacting in the bolometers. In this work, we present the characterization of the first light detectors developed by CALDER. We describe the analysis tools to evaluate the resonator parameters (resonant frequency and quality factors) taking into account simultaneously all the resonance distortions introduced by the read-out chain (as the feed-line impedance and its mismatch) and by the power stored in the resonator itself. We detail the method for the selection of the optimal point for the detector operation (maximizing the signal-to-noise ratio). Finally, we present the response of the detector to optical pulses in the energy range of 0-30 keV

    New application of superconductors: high sensitivity cryogenic light detectors

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    In this paper we describe the current status of the CALDER project, which is developing ultra-sensitive light detectors based on superconductors for cryogenic applications. When we apply an AC current to a superconductor, the Cooper pairs oscillate and acquire kinetic inductance, that can be measured by inserting the superconductor in a LC circuit with high merit factor. Interactions in the superconductor can break the Cooper pairs, causing sizable variations in the kinetic inductance and, thus, in the response of the LC circuit. The continuous monitoring of the amplitude and frequency modulation allows to reconstruct the incident energy with excellent sensitivity. This concept is at the basis of Kinetic Inductance Detectors (KIDs), that are characterized by natural aptitude to multiplexed read-out (several sensors can be tuned to different resonant frequencies and coupled to the same line), resolution of few eV, stable behavior over a wide temperature range, and ease in fabrication. We present the results obtained by the CALDER collaboration with 2x2 cm2 substrates sampled by 1 or 4 Aluminum KIDs. We show that the performances of the first prototypes are already competitive with those of other commonly used light detectors, and we discuss the strategies for a further improvement

    Energy resolution and efficiency of phonon-mediated Kinetic Inductance Detectors for light detection

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    The development of sensitive cryogenic light detectors is of primary interest for bolometric experiments searching for rare events like dark matter interactions or neutrino-less double beta decay. Thanks to their good energy resolution and the natural multiplexed read-out, Kinetic Inductance Detectors (KIDs) are particularly suitable for this purpose. To efficiently couple KIDs-based light detectors to the large crystals used by the most advanced bolometric detectors, active surfaces of several cm2^2 are needed. For this reason, we are developing phonon-mediated detectors. In this paper we present the results obtained with a prototype consisting of four 40 nm thick aluminum resonators patterned on a 2×\times2 cm2^2 silicon chip, and calibrated with optical pulses and X-rays. The detector features a noise resolution σE=154±7\sigma_E=154\pm7 eV and an (18±\pm2)%\% efficiency.Comment: 5 pages, 5 figure

    Discovery of the 151^{151}Eu α\alpha decay

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    We report on the first compelling observation of α\alpha decay of 151^{151}Eu to the ground state of 147^{147}Pm. The measurement was performed using a 6.15 g Li6_6Eu(BO3_3)3_3 crystal operated as a scintillating bolometer. The Q-value and half-life measured are: Q = 1948.9±6.9(stat.)±5.1(syst.)\pm 6.9(stat.) \pm 5.1(syst.) keV, and T1/2=(4.62±0.95(stat.)±0.68(syst.))×1018_{1/2}=\left( 4.62\pm0.95(stat.)\pm0.68(syst.)\right) \times 10^{18} y . The half-life prediction of nuclear theory using the Coulomb and proximity potential model are in good agreement with this experimental result

    New experimental limits on the alpha decays of lead isotopes

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    For the first time a PbWO4 crystal was grown using ancient Roman lead and it was run as a cryogenic detector. Thanks to the simultaneous and independent read-out of heat and scintillation light, the detector was able to discriminate beta/gamma interactions with respect to alpha particles down to low energies. New more stringent limits on the alpha decays of the lead isotopes are presented. In particular a limit of T_{1/2} > 1.4*10^20 y at a 90% C.L. was evaluated for the alpha decay of 204Pb to 200Hg

    Phonon and light read out of a Li 2MoO 4 crystal with multiplexed kinetic inductance detectors

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    Molybdenum based crystals such as Li 2MoO 4 and CaMoO4 are emerging as leading candidates for next generation experiments searching for neutrino-less double beta decay with cryogenic calorimeters (CUPID, AMoRE). The exquisite energy resolution and high radio-purity of these crystals come at the cost of a potentially detrimental background source: the two neutrinos double beta decay of 100Mo. Indeed, the fast half-life of this decay mode, combined with the slow response of cryogenic calorimeters, would result in pile-up events in the energy region of interest for neutrino-less double beta decay, reducing the experimental sensitivity. This background can be suppressed using fast and high sensitivity cryogenic light detectors, provided that the scintillation time constant itself does not limit the time resolution. We developed a new detection technique exploiting the high sensitivity, the fast time response and the multiplexing capability of Kinetic Inductance Detectors. We applied the proposed technique to a 2 × 2 × 2 cm3Li 2MoO 4 crystal, which was chosen as baseline option for CUPID. We measured simultaneously both the phonon and scintillation signals with KIDs. We derived the scintillation time constant of this compound at millikelvin temperatures obtaining tscint= 84.5 ± 4.5 (syst) ± 1.0 (stat) µs, constant between 10 and 190 mK
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