5 research outputs found
The Electronics and Data Acquisition System of the DarkSide Dark Matter Search
It is generally inferred from astronomical measurements that Dark Matter (DM)
comprises approximately 27\% of the energy-density of the universe. If DM is a
subatomic particle, a possible candidate is a Weakly Interacting Massive
Particle (WIMP), and the DarkSide-50 (DS) experiment is a direct search for
evidence of WIMP-nuclear collisions. DS is located underground at the
Laboratori Nazionali del Gran Sasso (LNGS) in Italy, and consists of three
active, embedded components; an outer water veto (CTF), a liquid scintillator
veto (LSV), and a liquid argon (LAr) time projection chamber (TPC). This paper
describes the data acquisition and electronic systems of the DS detectors,
designed to detect the residual ionization from such collisions
DarkSide-50, a background free experiment for dark matter searches
The existence of dark matter is inferred from gravitational effects, but its nature remains a deep mystery. One possibility, motivated by considerations in elementary particle physics, is that dark matter consists of elementary particles, such as the hypothesized Weakly Interacting Massive Particles (WIMPs), with mass ~ 100 GeV and cross-section ~ 10−47 cm2, that can be gravitationally trapped inside our galaxy and revealed by their scattering on nuclei. It should be possible to detect WIMPs directly, as the orbital motion of the WIMPs composing the dark matter halo pervading the galaxy should result in WIMP-nucleus collisions of sufficient energy to be observable in the laboratory. The DarkSide-50 experiment is a direct WIMP search using a Liquid Argon Time Projection Chamber (LAr-TPC) with an active mass of 50 kg with a high sensitivity and an ultra-low background detector
First Results from the DarkSide-50 Dark Matter Experiment at Laboratori Nazionali del Gran Sasso
We report the first results of DarkSide-50, a direct search for dark matter operating in the un-
derground Laboratori Nazionali del Gran Sasso (LNGS) and searching for the rare nuclear recoils
possibly induced by weakly interacting massive particles (WIMPs). The dark matter detector is a
Liquid Argon Time Projection Chamber with a
(
46.4
0.7
)
kg active mass, operated inside a 30 t or-
ganic liquid scintillator neutron veto, which is in turn installed at the center of a 1 kt water Cherenkov
veto for the residual flux of cosmic rays. We report here the null results of a dark matter search for
a
(
1422
67
)
kg d exposure with an atmospheric argon fill. This is the most sensitive dark matter
search performed with an argon target, corresponding to a 90% CL upper limit on the WIMP-nucleon
spin-independent cross section of 6.1
1
The Electronics and Data Acquisition System of the DarkSide Dark Matter Search
It is generally inferred from astronomical measurements th
at Dark
Matter (DM) comprises approximately 27% of the energy-dens
ity of the universe.
If DM is a subatomic particle, a possible candidate is a Weakl
y Interacting Mas-
sive Particle (WIMP), and the DarkSide-50 (DS) experiment i
s a direct search for
evidence of WIMP-nuclear collisions. DS is located undergr
ound at the Laboratori
Nazionali del Gran Sasso (LNGS) in Italy, and consists of thr
ee active, embedded
components; an outer water veto (CTF), a liquid scintillato
r veto (LSV), and
a liquid argon (LAr) time projection chamber (TPC). This pap
er describes the
data acquisition and electronic systems of the DS detectors
, designed to detect
the residual ionization from
The association of indwelling urinary catheter with delirium in hospitalized patients and nursing home residents: an explorative analysis from the "Delirium Day 2015"
BackroundUse of indwelling urinary catheter (IUC) in older adults has negative consequences, including delirium.AimThis analysis, from the Delirium Day 2015, a nationwide multicenter prevalence study, aim to evaluate the association of IUC with delirium in hospitalized and Nursing Homes (NHs) patients.MethodsPatients underwent a comprehensive geriatric assessment, including the presence of IUC; inclusion criteria were age>65 years, being Italian speaker and providing informed consent; exclusion criteria were coma, aphasia, end-of-life status. Delirium was assessed using the 4AT test (score4: possible delirium; scores 1-3: possible cognitive impairment).ResultsAmong 1867 hospitalized patients (mean age 82.07.5 years, 58% female), 539 (28.9%) had IUC, 429 (22.9%) delirium and 675 (36.1%) cognitive impairment. IUC was significantly associated with cognitive impairment (OR 1.60, 95% CI 1.19-2.16) and delirium (2.45, 95% CI 1.73-3.47), this latter being significant also in the subset of patients without dementia (OR 2.28, 95% CI 1.52-3.43). Inattention and impaired alertness were also independently associated with IUC. Among 1454 NHs residents (mean age 84.47.4 years, 70.% female), 63 (4.3%) had IUC, 535 (36.8%) a 4AT score4, and 653 (44.9%) a 4AT score 1-3. The multivariate logistic regression analysis did not show a significant association between 4AT test or its specific items with IUC, neither in the subset of patients without dementia.DiscussionWe confirmed a significant association between IUC and delirium in hospitalized patients but not in NHs residents.ConclusionEnvironmental and clinical factors of acute setting might contribute to IUC-associated delirium occurrence