14 research outputs found
The MURAVES muon telescope: technology and expected performances
The MURAVES project aims to study the inner structure of the upper part of the Mt. Vesuvius volcano by muon radiography (muography) technique. Very high energy muons, produced by cosmic rays in the at- mosphere, can penetrate large thickness of rocks. By measuring the at- tenuation of the muons flux trough the volcano cone is possible to obtain a 2D image of the density structure. Internal discontinuities, with a spa- tial resolution of about 10 m, can be, in principle, resolved. An absolute average density measurement can be provided too. The project, funded by the Italian Ministry of University, Research and Education (MIUR), is led by INGV and INFN. In this article the mechanical structure of the de- tectors and background suppression techniques are reported
Qualification study of SiPMs on a large scale for the CMVD Experiment
A Cosmic Muon Veto (CMV) detector using extruded plastic scintillators is
being designed around the mini-Iron Calorimeter (mini-ICAL) detector at the
transit campus of the India based Neutrino Observatory, Madurai for the
feasibility study of shallow depth underground experiments. The scintillation
signals that are produced in the plastic due to muon trajectories are absorbed
by wavelength shifting (WLS) fibres. The WLS fibres re-emit photons of longer
wavelengths and propagate those to silicon photo-multipliers (SiPMs). The SiPMs
detect these photons, producing electronic signals. The CMV detector will use
more than 700 scintillators to cover the mini-ICAL detector and will require
around 3000 SiPMs. The design goal for the cosmic muon veto efficiency of the
CMV is >99.99%. Hence, every SiPM used in the detector needs to be tested and
characterised to satisfy the design goal of CMV. A mass testing system was
developed for the measurement of gain and choice of the overvoltage ()
of each SiPMs using an LED driver. The is obtained by studying the
noise rate, the gain of the SiPM. This paper describes the experimental setup
used to test the SiPMs characteristics along with detailed studies of those
characteristics as a function of temperature.Comment: 16 pages, 20 figure
Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2
The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality
Químics catalans al món: Anna Pla-Dalmau. Fermi National Accelerator Laboratory, Illinois (EUA)
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Extruding plastic scintillator at Fermilab
An understanding of the costs involved in the production of plastic scintillators and the development of a less expensive material have become necessary with the prospects of building very large plastic scintillation detectors. Several factors contribute to the high cost of plastic scintillating sheets, but the principal reason is the labor-intensive nature of the manufacturing process. In order to significantly lower the costs, the current casting procedures had to be abandoned. Since polystyrene is widely used in the consumer industry, the logical path was to investigate the extrusion of commercial-grade polystyrene pellets with dopants to yield high quality plastic scintillator. This concept was tested and high quality extruded plastic scintillator was produced. The D0 and MINOS experiments are already using extruded scintillator strips in their detectors. An extrusion line has recently been installed at Fermilab in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new facility will serve to further develop and improve extruded plastic scintillator. This paper will discuss the characteristics of extruded plastic scintillator and its raw materials, the different manufacturing techniques and the current R&D program at Fermilab
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Extruded plastic scintillation detectors
As a way to lower the cost of plastic scintillation detectors, commercially available polystyrene pellets have been used in the production of scintillating materials that can be extruded into different profiles. The selection of the raw materials is discussed. Two techniques to add wavelength shifting dopants to polystyrene pellets and to extrude plastic scintillating strips are described. Data on light yield and transmittance measurements are presented
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Extruded plastic scintillator for MINERvA
An extrusion line has recently been installed at Fermilab in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new facility will serve to further develop and improve extruded plastic scintillator. Since polystyrene is widely used in the consumer industry, the logical path was to investigate the extrusion of commercial-grade polystyrene pellets with dopants to yield high quality plastic scintillator. The D0 and MINOS experiments are already using extruded scintillator strips in their detectors. A new experiment at Fermilab is pursuing the use of extruded plastic scintillator. A new plastic scintillator strip is being tested and its properties characterized. The initial results are presented here
Muography of the Puy de Dôme
Muon radiography is an imaging technique that relies on the transmis- sion of cosmic muons through matter. It allows the measurement of den- sity maps of large structures such as volcanoes. During the second half of 2013 the MURAY detector prototype carried out a data taking at the Puy de Dôme in the framework of the scientific collaboration with the experiment TOMUVOL in order to compare the results and performance of the two different detectors. Both experimental apparatuses measure a muon transmission of some orders of magnitude higher than that ex- pected highlighting a background that perturbs these measures