182 research outputs found
First test of an enriched CdWO scintillating bolometer for neutrinoless double-beta-decay searches
For the first time, a cadmium tungstate crystal scintillator enriched in
Cd has been succesfully tested as a scintillating bolometer. The
measurement was performed above ground at a temperature of 18 mK. The crystal
mass was 34.5 g and the enrichment level ~82 %. Despite a substantial pile-up
effect due to above-ground operation, the detector demonstrated a high energy
resolution (2-7 keV FWHM in 0.2-2.6 MeV energy range), a powerful
particle identification capability and a high level of internal radiopurity.
These results prove that cadmium tungstate is an extremely promising detector
material for a next-generation neutrinoless double-beta decay bolometric
experiment, like that proposed in the CUPID project (CUORE Upgrade with
Particle IDentification)
MANAGEMENT OF PATIENTS WITH ACUTE KIDNEY INJURY
Presented lecture is about management of a serious condition – acute kidney injury (AKI). It is intended for students, general practitioners, family physicians, therapists and those who may face with manifestations of AKI, and on which depends its timely diagnosis and the success of therapy. Definition, epidemiology, risk factors, causes, pathogenesis, classification, symptoms, diagnosis and differential diagnosis, treatment, complications, prognosis and prevention of AKI are described
Exploring CEvNS with NUCLEUS at the Chooz Nuclear Power Plant
Coherent elastic neutrino-nucleus scattering (CENS) offers a unique way
to study neutrino properties and to search for new physics beyond the Standard
Model. Nuclear reactors are promising sources to explore this process at low
energies since they deliver large fluxes of (anti-)neutrinos with typical
energies of a few MeV. In this paper, a new-generation experiment to study
CENS is described. The NUCLEUS experiment will use cryogenic detectors
which feature an unprecedentedly low energy threshold and a time response fast
enough to be operated in above-ground conditions. Both sensitivity to
low-energy nuclear recoils and a high event rate tolerance are stringent
requirements to measure CENS of reactor antineutrinos. A new experimental
site, denoted the Very-Near-Site (VNS) at the Chooz nuclear power plant in
France is described. The VNS is located between the two 4.25 GW
reactor cores and matches the requirements of NUCLEUS. First results of on-site
measurements of neutron and muon backgrounds, the expected dominant background
contributions, are given. In this paper a preliminary experimental setup with
dedicated active and passive background reduction techniques is presented.
Furthermore, the feasibility to operate the NUCLEUS detectors in coincidence
with an active muon-veto at shallow overburden is studied. The paper concludes
with a sensitivity study pointing out the promising physics potential of
NUCLEUS at the Chooz nuclear power plant
First array of enriched ZnSe bolometers to search for double beta decay
The R&D activity performed during the last years proved the potential of ZnSe
scintillating bolometers to the search for neutrino-less double beta decay,
motivating the realization of the first large-mass experiment based on this
technology: CUPID-0. The isotopic enrichment in Se, the ZnSe
crystals growth, as well as the light detectors production have been
accomplished, and the experiment is now in construction at Laboratori Nazionali
del Gran Sasso (Italy). In this paper we present the results obtained testing
the first three ZnSe crystals operated as scintillating bolometers, and
we prove that their performance in terms of energy resolution, background
rejection capability and intrinsic radio-purity complies with the requirements
of CUPID-0
ZnO-based scintillating bolometers: New prospects to study double beta decay of Zn
The first detailed study on the performance of a ZnO-based cryogenic
scintillating bolometer as a detector to search for rare processes in zinc
isotopes was performed. A 7.2 g ZnO low-temperature detector, containing more
than 80\% of zinc in its mass, exhibits good energy resolution of baseline
noise 1.0--2.7 keV FWHM at various working temperatures resulting in a
low-energy threshold for the experiment, 2.0--6.0 keV. The light yield for
/ events was measured as 1.5(3) keV/MeV, while it varies for
particles in the range of 0.2--3.0 keV/MeV. The detector demonstrate
an effective identification of the / events from events
using time-properties of only heat signals. %(namely, Rise time parameter). The
radiopurity of the ZnO crystal was evaluated using the Inductively Coupled
Plasma Mass Spectrometry, an ultra-low-background High Purity Ge
-spectrometer, and bolometric measurements. Only limits were set at the
level of (1--100) mBq/kg on activities of \Nuc{K}{40},
\Nuc{Cs}{137} and daughter nuclides from the U/Th natural decay chains. The
total internal -activity was calculated to be 22(2) mBq/kg, with a
major contribution caused by 6(1) mBq/kg of \Nuc{Th}{232} and 12(2) mBq/kg of
\Nuc{U}{234}. Limits on double beta decay (DBD) processes in \Nuc{Zn}{64} and
\Nuc{Zn}{70} isotopes were set on the level of
-- yr for various decay modes profiting from 271
h of acquired background data in the above-ground lab. This study shows a good
potential for ZnO-based scintillating bolometers to search for DBD processes of
Zn isotopes, especially in \Nuc{Zn}{64}, with the most prominent spectral
features at 10--20 keV, like the two neutrino double electron capture. A
10 kg-scale experiment can reach the experimental sensitivity at the level of
yr.Comment: Prepared for submission to JINST; 27 pages, 9 figures, and 7 table
CUPID-0: the first array of enriched scintillating bolometers for 0decay investigations
The CUPID-0 detector hosted at the Laboratori Nazionali del Gran Sasso, Italy, is the first large array of enriched scintillating cryogenic detectors for the investigation of82Se neutrinoless double-beta decay (0). CUPID-0 aims at measuring a background index in the region of interest (RoI) for 0at the level of 10- 3 counts/(keV kg years), the lowest value ever measured using cryogenic detectors. CUPID-0 operates an array of Zn82Se scintillating bolometers coupled with bolometric light detectors, with a state of the art technology for background suppression and thorough protocols and procedures for the detector preparation and construction. In this paper, the different phases of the detector design and construction will be presented, from the material selection (for the absorber production) to the new and innovative detector structure. The successful construction of the detector lead to promising preliminary detector performance which is discussed here
Tagging and localisation of ionizing events using NbSi transition edge phonon sensors for Dark Matter searches
In the context of direct searches of sub-GeV Dark Matter particles with
germanium detectors, the EDELWEISS collaboration has tested a new technique to
tag ionizing events using NbSi transition edge athermal phonon sensors. The
emission of the athermal phonons generated by the Neganov-Trofimov-Luke effect
associated with the drift of electrons and holes through the detectors is used
to tag ionization events generated in specific parts of the detector localized
in front of the NbSi sensor and to reject by more than a factor 5 (at 90% C.L.)
the background from heat-only events that dominates the spectrum above 3 keV.
This method is able to improve by a factor 2.8 the previous limit on
spin-independent interactions of 1 GeV/c2 WIMPs obtained with the same detector
and data set but without this tagging technique.Comment: 13 pages, 11 figure
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