A new generation photodetector for astroparticle physics: the VSiPMT

The VSiPMT (Vacuum Silicon PhotoMultiplier Tube) is an innovative design we proposed for a revolutionary photon detector. The main idea is to replace the classical dynode chain of a PMT with a SiPM (G-APD), the latter acting as an electron detector and amplifier. The aim is to match the large sensitive area of a photocathode with the performance of the SiPM technology. The VSiPMT has many attractive features. In particular, a low power consumption and an excellent photon counting capability. To prove the feasibility of the idea we first tested the performance of a special non-windowed SiPM by Hamamatsu (MPPC) as electron detector and current amplifier. Thanks to this result Hamamatsu realized two VSiPMT industrial prototypes. In this work, we present the results of a full characterization of the VSiPMT prototype

Ageing test of the ATLAS RPCs at X5-GIF

An ageing test of three ATLAS production RPC stations is in course at X5-GIF, the CERN irradiation facility. The chamber efficiencies are monitored using cosmic rays triggered by a scintillator hodoscope. Higher statistics measurements are made when the X5 muon beam is available. We report here the measurements of the efficiency versus operating voltage at different source intensities, up to a maximum counting rate of about 700Hz/cm^2. We describe the performance of the chambers during the test up to an overall ageing of 4 ATLAS equivalent years corresponding to an integrated charge of 0.12C/cm^2, including a safety factor of 5.Comment: 4 pages. Presented at the VII Workshop on Resistive Plate Chambers and Related Detectors; Clermont-Ferrand October 20th-22nd, 200

A versatile cryogenic system for liquid argon detectors

Detectors for direct dark matter search using noble gases in liquid phase as detection medium need to be coupled to liquefaction, purification and recirculation systems. A dedicated cryogenic system has been assembled and operated at the INFN-Naples cryogenic laboratory with the aim to liquefy and purify the argon used as active target in liquid argon detectors to study the scintillation and ionization signals detected by large SiPMs arrays. The cryogenic system is mainly composed of a double wall cryostat hosting the detector, a purification stage to reduce the impurities below one part per billion level, a condenser to liquefy the argon, a recirculation gas panel connected to the cryostat equipped with a custom gas pump. The main features of the cryogenic system are reported as well as the performances, long term operations and stability in terms of the most relevant thermodynamic parameters.Comment: Prepared for submission to JINST - LIDINE2022 September 21-23, 2022 - University of Warsaw Librar

Effectiveness and safety of a single freeze strategy of cryoballoon ablation of atrial fibrillation: an EHRA systematic review and meta-analysis

To conduct a systematic review and meta-analysis to compare the effectiveness and safety of cryoballoon ablation of atrial fibrillation (AF) performed using a single freeze strategy in comparison to an empiric double ('bonus') freeze strategy. We systematically searched MEDLINE, EMBASE, and CENTRAL databases from inception to 12 July 2020, for prospective and retrospective studies of patients undergoing cryoballoon for paroxysmal or persistent AF comparing a single vs. bonus freeze strategy. The main outcome was atrial arrhythmia-free survival and eligible studies required at least 12 months of follow-up; the primary safety outcome was a composite of all complications. Study quality was assessed using the Cochrane risk of bias tool and the Newcastle-Ottawa Scale. Thirteen studies (3 randomized controlled trials and 10 observational studies) comprising 3163 patients were eligible for inclusion (64% males, 71.5% paroxysmal AF, mean CHA2DS2-VASc score 1.3 ± 0.9). There was no significant difference in pooled effectiveness between single freeze strategy compared to double freeze strategy [relative risk (RR) 1.03; 95% confidence interval (CI): 0.98-1.07; I2 = 0%]. Single freeze procedures were associated with a significantly lower adverse event rate (RR 0.72; 95% CI: 0.53-0.98; I2 = 0%) and shorter average procedure time (90 ± 27 min vs. 121 ± 36 min, P < 0.001). A trend for lower risk of persistent phrenic nerve palsy was observed (RR 0.61; 95% CI: 0.37-1.01; I2 = 0%). The quality of included studies was moderate/good, with no evidence of significant publication bias. Single freeze strategy for cryoballoon of AF is as effective as an empiric double ('bonus') freeze strategy while appearing safer and probably quicker

The VSiPMT project

Photon detection is a key factor to study many physical processes in several areas of fundamental physics research. Focusing the attention on photodetectors for particle astrophysics, the future experiments aimed at the study of very high-energy or extremely rare phenomena (e.g. dark matter, proton decay, neutrinos from astrophysical sources) will require additional improvements in linearity, gain, quantum efficiency and single photon counting capability. To meet the requirements of this class of experiments, we propose a new design for a modern hybrid photodetector: the VSiPMT (Vacuum Silicon PhotoMultiplier Tube). The idea is to replace the classical dynode chain of a PMT with a SiPM, which therefore acts as an electron detector and amplifier. The aim is to match the large sensitive area of a photocathode with the performances of the SiPM technology. We now present the preliminary study we are performing to realize a 3-inches VSiPMT prototype

The Muon Spectrometer Barrel Level-1 Trigger of the ATLAS Experiment at LHC

The proton-proton beam crossing at the LHC accelerator at CERN will have a rate of 40 MHz at the project luminosity. The ATLAS Trigger System has been designed in three levels in order to select only interesting physics events reducing from that rate of 40 MHz to the foreseen storage rate of about 200 Hz. The First Level reduces the output rate to about 100 kHz. The ATLAS Muon Spectrometer has been designed to perform stand-alone triggering and measurement of muon transverse momentum up to 1 TeV/c with good resolution (from 3% at 10 GeV/c up to 10% at 1 TeV/c). In the Barrel region of the Muon Spectrometer the Level-1 trigger is given by means of three layers of Resistive Plate Chamber detectors (RPC): a gaseous detector working in avalanche mode composed by two plates of high-resistivity bakelite and two orthogonal planes of read-out strips. The logic of the Level-1 barrel muon trigger is based on the search of patterns of RPC hits in the three layers consistent with a high transverse momentum muon track originated from the interaction vertex. The associated trigger electronics is based on dedicated processors, the Coincidence Matrix boards, performing space coincidences and time gates and providing the RPC readout as well. A detailed simulation of the ATLAS Experiment and of both the hardware components and the logic of the Level-1 Muon Trigger in the barrel of the Muon Spectrometer has been performed. This simulation has been used not only to evaluate the performances of the system but also to define the hardware set-up such as the cabling of both the trigger detectors and the trigger electronics modules. A description of both the Level-1 Muon Trigger system in the barrel and the RPC detectors, with their cosmic rays quality tests, will be presented together with the trigger performances and rates calculations evaluated for muons over a wide range of pT and preliminary studies on the impact of accidental triggers due to low energy background particles in the experimental area

Presencia de indicadores microbiológicos en agua para consumo humano en San Cosme (Corrientes, Argentina)

El agua destinada al consumo humano no debe contener ningún agente patógeno, siendo necesario realizar análisis para determinar microorganismos indicadores de contaminación. Así, bacterias coliformes fecales informan contaminación fecal y Pseudomonas aeruginosa señala deterioro o recontaminación del agua. Con el objeto de establecer la presencia de tales indicadores en una zona rural y evaluar la calidad microbiológica del agua para consumo humano, se investigaron dos tipos diferentes de fuentes de agua, una subterránea (pozo y perforación) y otra superficial (laguna). Las muestras colectadas en frascos estériles se mantuvieron refrigeradas a 4-6°C, determinándose la cantidad presuntiva de coliformes totales en series de cinco tubos de caldo MacConkey y confirmación de positivos con caldo brila a 37°C. La confirmación de la presencia de coliformes fecales y P. aeruginosa se efectuó usando el medio selectivo que contiene cristal violeta a 37°C, repicando en agar cetrimide a 37°C. En los pozos se registraron los valores más altos de contaminación por coliformes fecales, siendo la perforación la fuente de agua de menor riesgo de polución. En cuanto a P. aeruginosa, su presencia se constató en las tres fuentes de agua, en distintos períodos de tiempo, siendo el agua de laguna la que presentó mayor contaminación. De acuerdo al Código Alimentario Argentino, estos resultados muestran la ineptitud para el consumo de las aguas analizada

System Test of the ATLAS Muon Spectrometer in the H8 Beam at the CERN SPS

An extensive system test of the ATLAS muon spectrometer has been performed in the H8 beam line at the CERN SPS during the last four years. This spectrometer will use pressurized Monitored Drift Tube (MDT) chambers and Cathode Strip Chambers (CSC) for precision tracking, Resistive Plate Chambers (RPCs) for triggering in the barrel and Thin Gap Chambers (TGCs) for triggering in the end-cap region. The test set-up emulates one projective tower of the barrel (six MDT chambers and six RPCs) and one end-cap octant (six MDT chambers, A CSC and three TGCs). The barrel and end-cap stands have also been equipped with optical alignment systems, aiming at a relative positioning of the precision chambers in each tower to 30-40 micrometers. In addition to the performance of the detectors and the alignment scheme, many other systems aspects of the ATLAS muon spectrometer have been tested and validated with this setup, such as the mechanical detector integration and installation, the detector control system, the data acquisition, high level trigger software and off-line event reconstruction. Measurements with muon energies ranging from 20 to 300 GeV have allowed measuring the trigger and tracking performance of this set-up, in a configuration very similar to the final spectrometer. A special bunched muon beam with 25 ns bunch spacing, emulating the LHC bunch structure, has been used to study the timing resolution and bunch identification performance of the trigger chambers. The ATLAS first-level trigger chain has been operated with muon trigger signals for the first time

Safety and effectiveness of edoxaban in a real-world clinical setting: Two-year follow-up of the ETNA-AF-Europe study

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Daiichi Sankyo Europe OnBehalf ETNA-AF-Europe investigators Background Oral anticoagulation (OAC) for stroke prevention is essential in the management of patients with atrial fibrillation (AF). The assessment of OAC use in routine clinical care and the effects of this therapy on outcomes and safety are important. Purpose: We analysed two-year outcome data with adjudicated follow-up results in 13,417 patients with AF treated with edoxaban. Methods: ETNA-AF-Europe (Clinicaltrials.gov: NCT02944019) enrolled 13,417 consecutive patients with AF treated with edoxaban in 825 centres in 10 European countries and 2-year prospectively collected, real world data is presented. Results: Edoxaban was prescribed according to licence recommendations in 83.1% (n = 11,146) of patients (Table). Whilst three quarters of patients were prescribed edoxaban 60 mg (n = 10,248, 76.4%), the quarter prescribed edoxaban 30 mg were older (79.5 versus 71.8 years), had a higher stroke risk (CHA2DS2-VASc score: 3.9 versus 3.0) and a higher bleeding risk (HAS-BLED score: 2.9 versus 2.4). Thromboembolic and bleeding events were more common in patients receiving edoxaban 30 mg OD without differences in intracranial haemorrhage (ICH) (Figure). Patients prescribed a non-recommended dose of edoxaban had a numerically higher stroke risk (CHA2DS2-VASc score: 3.6 versus 3.1) with subsequent higher rates of ischemic stroke and mortality, however they also had higher bleeding rates, with the exception of ICH (table) despite a similar initial bleeding risk (HAS-BLED score: 2.7 versus 2.5). Conclusions: In this large, European data set reporting two-year outcomes on edoxaban therapy, no additional safety signals were observed and event rates were in line with those observed in ETNA-AF after 1 year and in ENGAGE AF-TIMI 48, re-affirming the safety and effectiveness of edoxaban licence recommendations in a real world setting of patients with AF. All key events of interest, other than intracranial haemorrhage, were numerically lower in patients prescribed the licenced recommended dose. Outcomes with rec. vs non-rec. dosesn (%/year [95%CI])Recommended dose (n = 11,146; 83.1%)Non-recommended dose (n = 2271; 16.9%)Any stroke/SEE138 (0.68 [0.57;0.80])31 (0.76 [0.51;1.07])Ischaemic stroke99 (0.48 [0.39;0.59])26 (0.63 [0.41; 0.93])Major bleeding189 (0.93 [0.80;1.07])49 (1.20 [0.89;1.59])Intracranial haemorrhage43 (0.21 [0.15;0.28])7 (0.17 [0.07;0.35])All-cause mortality729 (3.55 [3.30;3.82])208 (5.04 [4.38;5.78])CV mortality405 (1.97 [1.79;2.18])113 (2.74 [2.26;3.30])CI, confidence interval; CV, cardiovascular; rec., recommended; SEE, systemic embolic event.Abstract Figure. Annualised event rates at 2-year F