0000000000222564
AUTHOR
A. Brogna
Construction of large-area micro-pattern gaseous detectors
Particle physics experiments often comprise tracking detectors with areas of up to a few square meters. If a spatial resolution of the order of 100μm and high-rate capability are required, Micro Pattern Gaseous Detectors (MPGD) are a cost-effective solution. However, the construction of large-area MPGDs is challenging, since tight fabrication tolerances have to be met to guarantee a stable and homogeneous performance. A precision granite table and an automated 3-D positioning system with an attached laser sensor, both inside a laminar-flow cell, have therefore been set up in the PRISMA Detector Lab at Mainz. Currently, this infrastructure is used to produce drift panels for the upgrade of t…
Measurement of the response of Silicon Photomultipliers from single photon detection to saturation
Abstract The development of Silicon Photomultipliers (SiPM) is very dynamic and a large variety of types exists. Important SiPM characteristics include the size and number of pixels, the gain, the photon detection efficiency (PDE), the recovery time, and correlated noise. SiPMs are particularly suitable for single-photon detection and low-intensity exposures. For photon numbers (PDE corrected) reaching the number of pixels, however, the sensors saturate. In this work, we present comprehensive response measurements for state-of-the-art SiPMs using an experimental setup based on a tunable picosecond laser. Several models are applied to the measured response curves, taking particularly correla…
The e-ASTROGAM gamma-ray space observatory for the multimessenger astronomy of the 2030s
e-ASTROGAM is a concept for a breakthrough observatory space mission carrying a gamma-ray telescope dedicated to the study of the non-thermal Universe in the photon energy range from 0.15 MeV to 3 GeV. The lower energy limit can be pushed down to energies as low as 30 keV for gamma-ray burst detection with the calorimeter. The mission is based on an advanced space-proven detector technology, with unprecedented sensitivity, angular and energy resolution, combined with remarkable polarimetric capability. Thanks to its performance in the MeV-GeV domain, substantially improving its predecessors, e-ASTROGAM will open a new window on the non-thermal Universe, making pioneering observations of the…
Development of Structured Scintillator Tiles for High-Granularity Calorimeters
Calorimeters with a fine 3-D segmentation are considered to be a very promising technology for future high-energy physics experiments, since they provide in combination with particle flow algorithms excellent jet energy resolution and particle identification capabilities. Depending on the size, millions of individual channels consisting of a photosensor coupled to a scintillator tile have to be assembled. The usage of structured plastic scintillators with optically separated segments simplifies the mass production. We present the design, production, and performance of a 36 cm × 36 cm scintillator tile divided into 144 segments matching the geometry of the SiPM-based calorimeter frontend dev…
Autosomal recessive hypercholesterolemia in a Sicilian kindred harboring the 432insA mutation of the ARH gene
Abstract We describe a Sicilian family presenting a recessive form of hypercholesterolemia harboring a mutation of the autosomal recessive hypercholesterolemia (ARH) gene. In two of the three sibs, a 26-year-old male and a 22-year-old female, a severe hypercholesterolemia was diagnosed with very high levels of plasma cholesterol (15.9 and 12.2 mmol/l, respectively); tendon xanthomatas and xanthelasms were present and in the male proband was documented a diffuse coronary atherosclerotic disease with a rapid and fatal progression. Both the parents had normal or slightly increased levels of plasma cholesterol. All causes of secondary hypercholesterolemia were ruled out as well as an involvemen…
Latest Frontier Technology and Design of the ATLAS Calorimeter Trigger Board Dedicated to Jet Identification for the LHC Run 3
To cope with the enhanced luminosity of the beam delivered by the Large Hadron Collider (LHC) in 2020, the “A Toroidal LHC ApparatuS” (ATLAS) experiment has planned a major upgrade. As part of this, the trigger at Level1 based on calorimeter data will be upgraded to exploit fine-granularity readout using a new system of Feature Extractors, which each use different physics objects for the trigger selection. The article focusses on the jet Feature EXtractor (jFEX) prototype, one of the three types of Feature Extractors. Up to 2 TB/s have to be processed to provide jet identification (including large area jets) and measurements of global variables within few hundred nanoseconds latency budget.…
A novel mutation of the DHCR7 gene in a sicilian compound heterozygote with Smith-Lemli-Opitz Syndrome
Introduction: Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder of cholesterol biosynthesis, resulting from deficient 7-dehydrocholesterol reductase (3β-hydroxysterol Δ7-reductase) activity, the enzyme responsible for conversion of 7-dehydrocholesterol to cholesterol. SLOS is most common among people of European descent, with a reported incidence of 1 per 20 000–60 000 newborns, depending on the diagnostic criteria and the reference population. More than 80 different mutations have been identified in several hundred patients. In Italy, SLOS appears to be a rare condition, probably because of underdiagnosis. Method: We analyzed by direct sequencing the 7-dehydrocholesterol…
Comparison of Silicon Photomultiplier Characteristics using Automated Test Setups
Silicon Photomultipliers (SiPM) are photo-sensors consisting of an array of hundreds to thousands pixels with a typical pitch of 10-100 μm. They exhibit an excellent photon counting and time resolution. Therefore applications of SiPMs are emerging in many fields. In order to characterize SiPMs, the PRISMA Detector Lab at Mainz has established three automated test setups. Setup-A is dedicated to measure the gain, the dark count rate and the optical crosstalk probability. The temperature dependencies are characterized by operating the setup in a climate chamber. Setup-B is an optical system to measure the photon detection efficiency. Setup-C addresses the most challenging aspect of comparing …
Design and testing of the high speed signal densely populated ATLAS calorimeter trigger board dedicate to jet identification
Abstract—The ATLAS experiment has planned a major upgrade in view of the enhanced luminosity of the beam delivered by the Large Hadron Collider (LHC) in 2021. As part of this, the trigger at Level-1 based on calorimeter data will be upgraded to exploit fine-granularity readout using a new system of Feature Extractors (three in total), which each uses different physics objects for the trigger selection. The contribution focusses on the jet Feature EXtractor (jFEX) prototype. Up to a data volume of 2 TB/s has to be processed to provide jet identification (including large area jets) and measurements of global variables within few hundred nanoseconds latency budget. Such requirements translate …
Operation of silicon photomultipliers as photosensors of liquid xenon detectors
Silicon Photomultipliers as photosensors for liquid xenon detectors are an attractive alternative to photomultiplier tubes: liquid xenon detectors employed in low background experiments or compact Compton cameras can take advantage of the small sensor mass and dimensions, the larger light collection coming from a more packed tiling of the readout plane, and possibly a smaller cost per area. We investigate the operation in liquid xenon of samples developed by Ketek GmbH. To provide sensitivity to the liquid xenon scintillation light wavelength, 178 nm, the inactive entrance layer of the device has been thinned. The operation of such devices at temperatures as low as −100°C has been verified,…