1,791 research outputs found
A new Low Gain Avalanche Diode concept: the double-LGAD
This paper describes the new concept of the double-LGAD. The goal is to
increase the charge at the input of the electronics, keeping a time resolution
equal or better than a standard (single) LGAD; this has been realized by adding
the charges of two coupled LGADs while still using a single front-end
electronics. The study here reported has been done starting from single LGAD
with a thickness of 25 \textmu{m}, 35 \textmu{m} and 50 \textmu{m}.Comment: arXiv admin note: text overlap with arXiv:2208.0571
A simulation tool for MRPC telescopes of the EEE project
The Extreme Energy Events (EEE) Project is mainly devoted to the study of the
secondary cosmic ray radiation by using muon tracker telescopes made of three
Multigap Resistive Plate Chambers (MRPC) each. The experiment consists of a
telescope network mainly distributed across Italy, hosted in different building
structures pertaining to high schools, universities and research centers.
Therefore, the possibility to take into account the effects of these structures
on collected data is important for the large physics programme of the project.
A simulation tool, based on GEANT4 and using GEMC framework, has been
implemented to take into account the muon interaction with EEE telescopes and
to estimate the effects on data of the structures surrounding the experimental
apparata.A dedicated event generator producing realistic muon distributions,
detailed geometry and microscopic behavior of MRPCs have been included to
produce experimental-like data. The comparison between simulated and
experimental data, and the estimation of detector resolutions is here presented
and discussed
New Eco-gas mixtures for the Extreme Energy Events MRPCs: results and plans
The Extreme Energy Events observatory is an extended muon telescope array,
covering more than 10 degrees both in latitude and longitude. Its 59 muon
telescopes are equipped with tracking detectors based on Multigap Resistive
Plate Chamber technology with time resolution of the order of a few hundred
picoseconds. The recent restrictions on greenhouse gases demand studies for new
gas mixtures in compliance with the relative requirements. Tetrafluoropropene
is one of the candidates for tetrafluoroethane substitution, since it is
characterized by a Global Warming Power around 300 times lower than the gas
mixtures used up to now. Several mixtures have been tested, measuring
efficiency curves, charge distributions, streamer fractions and time
resolutions. Results are presented for the whole set of mixtures and operating
conditions, %. A set of tests on a real EEE telescope, with cosmic muons, are
being performed at the CERN-01 EEE telescope. The tests are focusing on
identifying a mixture with good performance at the low rates typical of an EEE
telescope.Comment: 8 pages, 6 figures, proceedings for the "XIV Workshop on Resistive
Plate Chambers and Related Detectors" (19-23 February 2018), Puerto Vallarta,
Jalisco State, Mexic
INFN What Next: Ultra-relativistic Heavy-Ion Collisions
This document was prepared by the community that is active in Italy, within
INFN (Istituto Nazionale di Fisica Nucleare), in the field of
ultra-relativistic heavy-ion collisions. The experimental study of the phase
diagram of strongly-interacting matter and of the Quark-Gluon Plasma (QGP)
deconfined state will proceed, in the next 10-15 years, along two directions:
the high-energy regime at RHIC and at the LHC, and the low-energy regime at
FAIR, NICA, SPS and RHIC. The Italian community is strongly involved in the
present and future programme of the ALICE experiment, the upgrade of which will
open, in the 2020s, a new phase of high-precision characterisation of the QGP
properties at the LHC. As a complement of this main activity, there is a
growing interest in a possible future experiment at the SPS, which would target
the search for the onset of deconfinement using dimuon measurements. On a
longer timescale, the community looks with interest at the ongoing studies and
discussions on a possible fixed-target programme using the LHC ion beams and on
the Future Circular Collider.Comment: 99 pages, 56 figure
Mechanisms of pulmonary fibrosis: role of activated myofibroblasts and NADPH oxidase
A common feature of pathological fibrosis involving the lung and other organs is the persistent activation of myofibroblasts in injured tissues. Recent evidence supports the role of a member of the NADPH oxidase (NOX) gene family, NOX4, in myofibroblast differentiation, matrix synthesis and contractility. Additionally, NOX4 may contribute directly or indirectly to alveolar epithelial cell death, while myofibroblasts themselves acquire an apoptosis-resistant phenotype. Thus, NOX4 may be responsible for the cardinal features of progressive fibrosis - myofibroblast activation and epithelial cell dysrepair. Therapeutic targeting of NOX4 is likely to be effective in progressive cases of fibrosis involving multiple organs
Direct detection of charged particles with SiPMs
The direct response of Silicon PhotoMultipliers being traversed by a MIP charged particle have been studied in a systematic way for the first time. Using beam test data, time resolution and the crosstalk probability have been measured. A characterization of the SiPM by means of a laser beam is also reported. The results obtained for different sensors indicate a measured time resolution around 40-70 ps. Although particles are expected to traverse only one SPAD per event, crosstalk measurements on different sensors indicate an unexpected higher value with respect to the one related to the sensor noise
Measurements of the Cherenkov effect in direct detection of charged particles with SiPMs
In this paper, different Silicon PhotoMultiplier (SiPM) sensors have been
tested with charged particles to characterize the Cherenkov light produced in
the sensor protection layer. A careful position scan of the SiPM response has
been performed with different prototypes, confirming the large number of firing
cells and proving almost full efficiency, with the SiPM filling factor
essentially negligible. This study also allowed us to study the time resolution
of such devices as a function of the number of firing cells, reaching values
below 20 ps. These measurements provide significant insight into the
capabilities of SiPM sensors in direct detection of charged particles and their
potential for several applications
Fetal programming and systemic sclerosis
Objective This study investigated whether birthweight is linked to an increased risk of the development of systemic sclerosis. Study Design This was a multicenter case-control study with perinatal data that were obtained from 332 cases with systemic sclerosis and 243 control subjects. Birthweight was treated as a dichotomous variable (<2500 g vs 652500 g); low birthweight was defined as a weight <2500 g; small for gestational age was defined as birthweight <10th percentile for gestational age adjusted for sex. The relationship between systemic sclerosis and both low birthweight and small for gestational age was expressed with the crude (univariate analysis) and adjusted (multivariate analysis) odds ratio (OR). Results Significantly increased ORs were observed in the univariate analysis for low birthweight (OR, 2.59; 95% confidence interval [CI], 1.39-5.05) and small for gestational age (OR, 2.60; 95% CI, 1.34-5.32) subjects. Similarly increased risks were confirmed for both conditions in the multivariate analysis (OR, 3.93; 95% CI, 1.92-8.07; and OR, 2.58; 95% CI, 1.28-5.19), respectively. Conclusion Low birthweight and small for gestational age at birth are risk factors for the adult onset of systemic sclerosis
Outreach activities of the Extreme Energy Events Project
The Extreme Energy Events Project (EEE) represents a breakthrough in outreach activities in Cosmic Ray Physics: high school students are protagonists of an experiment to measure Extensive Air Showers at ground. They start their experience at CERN with the construction of the three high performing Multigap Resistive Plate Chambers constituting the telescope that is then installed inside their school; then they take care of the telescope operation and data analysis. Presently 60 telescopes are installed in Italy and, since 2014, coordinated data taking have been performed during each school year providing a huge amount of candidate muon tracks. Every year hundreds of students and teachers are involved in the activities directly correlated to EEE. The COVID-19 pandemic has strongly affected the experimental activities of the EEE Project. However in the last two years the online activities were strengthened, with an intense programme of collaboration meetings, masterclasses, and hugely successful topical seminars. Starting from the fall of 2021, the improvement of epidemiological situation made it possible to start some of the EEE activities in presence
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