212 research outputs found
Design and Test of the Off-Detector Electronics for the CMS Barrel Muon Trigger
Drift Tubes chambers are used in the CMS barrel for tagging the passage of high Pt muons generated in a LHC event and for triggering the CMS data read out. The Sector Collector (SC) system synchronizes the track segments built by trigger modules on the chambers and deliver them to reconstruction processors (Track Finder, TF) that assemble full muon tracks. Then, the Muon Sorter (MS) has to select the best four candidates in the barrel and to filter fake muons generated by the TF system redundancy. The hardware implementations of the Sector Collector and Muon Sorter systems satisfy radiation, I/O and fast timing constraints using several FPGA technologies. The hardware was tested with custom facilities, integrated with other trigger subsystems, and operated in a beam test. A test beam on a 40 MHz bunched beam validated the local trigger electronics and off-detector prototype cards and the synchronization tools. The CMS Magnet Test and Cosmic challenge in 2006 proved stable and reliable operation of the Drift Tubes trigger and its integration with other trigger systems and with the readout system. Constraints, design, test and operation of the modules are presented
Use of antifuse-FPGAs in the Track-Sorter-Master of the CMS Drift Tube Chambers
The front-end system of the Silicon Drift Detectors (SDDs) of the ALICE experiment is made of two ASICs. The first chip performs the preamplification, temporary analogue storage and analogue-to-digital conversion of the detector signals. The second chip is a digital buffer that allows for a significant reduction of the connection from the front-end module to the outside world. In this paper, the results achieved on the first complete prototype of the front-end system for the SDDs of ALICE are presented
DT Sector Collector electronics design and construction
The CMS detector at LHC is equipped with Drift Tubes (DT) chambers for muon detection and triggering in the barrel region. The Sector Collector (SC) modules collect the track segments reconstructed by on-chamber trigger electronics. Data from different chambers are aligned in time and sent to the subsequent reconstruction processors via optical links. Several FPGA devices performing the processing of the data were designed in VHDL, including spy features to monitor the trigger data flow. A test jig was set up with custom hardware and software in order to fully validate final production boards. Installation and commissioning in CMS provided first experience with the synchronization and monitoring tools
Left atrial trajectory impairment in hypertrophic cardiomyopathy disclosed by geometric morphometrics and parallel transport
The analysis of full Left Atrium (LA) deformation and whole LA deformational trajectory in time has been poorly investigated and, to the best of our knowledge, seldom discussed in patients with Hypertrophic Cardiomyopathy. Therefore, we considered 22 patients with Hypertrophic Cardiomyopathy (HCM) and 46 healthy subjects, investigated them by three-dimensional Speckle Tracking Echocardiography, and studied the derived landmark clouds via Geometric Morphometrics with Parallel Transport. Trajectory shape and trajectory size were different in Controls versus HCM and their classification powers had high AUC (Area Under the Receiving Operator Characteristic Curve) and accuracy. The two trajectories were much different at the transition between LA conduit and booster pump functions. Full shape and deformation analyses with trajectory analysis enabled a straightforward perception of pathophysiological consequences of HCM condition on LA functioning. It might be worthwhile to apply these techniques to look for novel pathophysiological approaches that may better define atrio-ventricular interaction
Acute atrial ischemia associates with early but not late new-onset atrial fibrillation in STEMI patients treated with primary PCI: relationship with in-hospital outcomes
Abstract
Funding Acknowledgements
Type of funding sources: None.
OnBehalf
N/A
Background. New-onset atrial fibrillation (NOAF) is known to be a common complication in STEMI patients undergoing primary percutaneous coronary intervention (PCI), which is associated with a negative short- and long-term prognosis. Recently, two distinct phenotypes of NOAF have been described, namely early (EAF) and late NOAF (LAF). However, whether EAF and LAF recognize different pathogenetic mechanisms is unknown.
Purpose. To investigate atrial branches occlusion and EAF or LAF onset in STEMI patients undergoing primary PCI.
Methods. Retrospective cohort study including 155 STEMI patients. Patients were divided into 3 groups: sinus rhythm (SR), EAF or LAF. Clinical characteristics, angiographic features including occlusion of atrial branches, namely ramus ostia cavae superioris (ROCS), atrio-ventricular node artery (AVNA), right intermediate atrial artery (RIAA) and left intermediate atrial artery (LIAA), were assessed. We also investigated in-hospital complications, death, and a composite of major post-NOAF adverse events (AEs) including cardiogenic shock, acute pulmonary edema, sustained ventricular tachycardia and ventricular fibrillation.
Results. Mean age was 63.8 ± 11.9 years; 78.7% of men. NOAF was detected in 22 (14.2%) patients: 10 (6.4%) EAF and 12 LAF (7.7%). Compared to EAF, LAF patients were older (p = 0.013), with higher GRACE risk score (p = 0.014) and Killip class (p = 0.015), depressed ejection fraction (p = 0.007), elevated filling pressures (p = 0.029), higher c-reactive protein (p = 0.014) and more TIMI flow <3 (p = 0.015). As shown in Figure 1, EAF was associated with higher prevalence of occluded ROCS (p = 0.010), AVNA (p = 0.005) and RIAA (p < 0.001), compared to SR. Moreover, EAF patients had more frequently ≥2 diseased atrial branches than SR (19.5%, p < 0.001) and LAF (25%, p < 0.030) patients. In LAF patients, a higher incidence of pre-PCI cardiogenic shock, post-PCI AEs (p = 0.019 vs SR; p = 0.029 vs EAF) and death (p = 0.004 vs SR) was found.
Conclusions. The occlusion of atrial branches is associated with early but not late NOAF following STEMI. LAF patients had worse in-hospital AEs and mortality. Abstract Figure
A multi-channel trigger and acquisition board for TDC-based readout: Application to the cosmic rays detector of the PolarQuEEEst 2018 project
In the summer of 2018, the PolarQuEEEst experiment accomplished a measurement of cosmic rays flux in the Arctic. The detector, installed on a sailboat, was based on scintillation tiles read by a total of 16 SiPM. A multi-channel board (called TRB) has been designed to process the discriminated SiPM signals providing both self-trigger capability and time-to-digital conversion; it was based on a Cyclone-V Intel FPGA. Time-to-digital conversion has been implemented both into FPGA and with the HPTDC chip (as a backup). In this document the board will be described, enlightening the main features and the achieved performance. Lastly, the PolarQuEEEst measurement campaigns will be briefly described, showing how the TRB board has proved to be effective for experiments which require low power consumption, integration with position and environmental sensors and great portability as well. Final thoughts on future improvements will be also discussed
Performance of scintillating tiles with direct silicon-photomultiplier (SiPM) readout for application to large area detectors
The light yield, the time resolution and the efficiency of different types of scintillating tiles with direct Silicon Photomultiplier readout and instrumented with a customised front-end electronics have been measured at the Beam Test Facility of Laboratori Nazionali di Frascati and several test stands. The results obtained on minimum ionising particles with different detector configurations are presented. A time resolution of the order of 300 ps, a light yield of more than 230 photo-electrons, and an efficiency better than 99.8% are obtained with ∼ 225 cm2 large area tiles. This technology is suitable for a wide range of applications in high-energy physics, in particular for large area muon and timing detectors
Test and simulation of plastic scintillator strips readout by silicon photomultipliers
We studied the light collection in plastic scintillator strips, optimized for the detection of Minimum Ionizing Particles (MIPs). The light is collected by Wave Length Shifter (WLS) fibers and detected by Silicon Photo Multipliers (SiPMs). The study is based on prototypes developed for the muon detector of SuperB experiment. In parallel to measurement made on various type of geometries, a complete simulation suite, based on FLUKA, was developed. The simulation parameters were tuned by comparison with real data. In this way, we were able to study the effects of geometries and assembling procedures on light collection and provide a useful simulation tool for the design of future prototypes
Search for antihelium in cosmic rays
The Alpha Magnetic Spectrometer (AMS) was flown on the space shuttle
Discovery during flight STS-91 in a 51.7 degree orbit at altitudes between 320
and 390 km. A total of 2.86 * 10^6 helium nuclei were observed in the rigidity
range 1 to 140 GV. No antihelium nuclei were detected at any rigidity. An upper
limit on the flux ratio of antihelium to helium of < 1.1 * 10^-6 is obtained.Comment: 18 pages, Latex, 9 .eps figure
Protons in near earth orbit
The proton spectrum in the kinetic energy range 0.1 to 200 GeV was measured
by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS-91 at
an altitude of 380 km. Above the geomagnetic cutoff the observed spectrum is
parameterized by a power law. Below the geomagnetic cutoff a substantial second
spectrum was observed concentrated at equatorial latitudes with a flux ~ 70
m^-2 sec^-1 sr^-1. Most of these second spectrum protons follow a complicated
trajectory and originate from a restricted geographic region.Comment: 19 pages, Latex, 7 .eps figure
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