2,233 research outputs found
Components Qualification for a Possible use in the Mu2e Calorimeter Waveform Digitizers
The Mu2e experiment at Fermilab searches for the charged flavor violating
conversion of a muon into an electron in the Coulomb field of a nucleus. The
detector consists of a straw tube tracker and a CSI crystal electromagnetic
calorimeter, both housed in a superconducting solenoid. Both the front-end and
the digital electronics, located inside the cryostat, will be operated in
vacuum under a 1 T magnetic field, having to sustain the high flux of neutrons
and ionizing particles coming from the muons stopping target. These harsh
experimental conditions make the design of the calorimeter waveform digitizer
quite challenging. All the selected commercial devices must be tested
individually and qualified for radiation hardness and operation in high
magnetic field. At the moment the expected particles flux and spectra at the
digitizers location are not completely simulated and we are using initial rough
estimates to select the components for the first prototype. We are gaining
experience in the qualification procedures using the selected components but
the choice will be frozen only when dose and neutron flux simulations will be
completed. The experimental results of the first qualification campaign are
presented.Comment: TWEPP 2016 - Topical Workshop on Electronics for Particle Physics,
26-30 September 2016, Karlsruhe Institute of Technology (KIT
Role of omega-3 polyunsaturated fatty acids in diet of patients with rheumatic diseases
The beneficial effects of ω-3 polyunsaturated fatty acids have been widely described in the literature in particular those on cardiovascular system. In the last decade there has been an increased interest in the role of these nutrients in the reduction of articular inflammation as well as in the improvement of clinical symptoms in subjects affected by rheumatic diseases, in particular rheumatoid arthritis (RA). Nutritional supplementation with ω-3 may represent an additional therapy to the traditional pharmacological treatment due to the anti-inflammatory properties which characterize this class of lipids: production of alternative eicosanoids, reduction of inflammatory cytochines, reduction of T-lymphocytes activation, reduction of catabolic enzymes activity. The encouraging results of dietetic therapy based on ω- 3 in RA are leading researchers to test their effectiveness on patients with other rheumatic conditions such as systemic lupus erythematosus and ankylosing spondylitis. Nutritional therapy based on food rich in ω-3 or on supplementation with fish oil capsules, proved to be a valid support to he treatment of chronic inflammatory rheumatic diseases
Thermal evolution of hybrid stars within the framework of a nonlocal Nambu--Jona-Lasinio model
We study the thermal evolution of neutron stars containing deconfined quark
matter in their core. Such objects are generally referred to as quark-hybrid
stars. The confined hadronic matter in their core is described in the framework
of non-linear relativistic nuclear field theory. For the quark phase we use a
non-local extension of the SU(3) Nambu Jona-Lasinio model with vector
interactions. The Gibbs condition is used to model phase equilibrium between
confined hadronic matter and deconfined quark matter. Our study indicates that
high-mass neutron stars may contain between 35 and 40 % deconfined quark-hybrid
matter in their cores. Neutron stars with canonical masses of around would not contain deconfined quark matter. The central proton
fractions of the stars are found to be high, enabling them to cool rapidly.
Very good agreement with the temperature evolution established for the neutron
star in Cassiopeia A (Cas A) is obtained for one of our models (based on the
popular NL3 nuclear parametrization), if the protons in the core of our stellar
models are strongly paired, the repulsion among the quarks is mildly repulsive,
and the mass of Cas A has a canonical value of .Comment: 10 pages, 7 figure
The artificial retina for track reconstruction at the LHC crossing rate
We present the results of an R&D study for a specialized processor capable of
precisely reconstructing events with hundreds of charged-particle tracks in
pixel and silicon strip detectors at , thus suitable for
processing LHC events at the full crossing frequency. For this purpose we
design and test a massively parallel pattern-recognition algorithm, inspired to
the current understanding of the mechanisms adopted by the primary visual
cortex of mammals in the early stages of visual-information processing. The
detailed geometry and charged-particle's activity of a large tracking detector
are simulated and used to assess the performance of the artificial retina
algorithm. We find that high-quality tracking in large detectors is possible
with sub-microsecond latencies when the algorithm is implemented in modern,
high-speed, high-bandwidth FPGA devices.Comment: 3 pages, 3 figures, ICHEP14. arXiv admin note: text overlap with
arXiv:1409.089
Simulation and performance of an artificial retina for 40 MHz track reconstruction
We present the results of a detailed simulation of the artificial retina
pattern-recognition algorithm, designed to reconstruct events with hundreds of
charged-particle tracks in pixel and silicon detectors at LHCb with LHC
crossing frequency of . Performances of the artificial retina
algorithm are assessed using the official Monte Carlo samples of the LHCb
experiment. We found performances for the retina pattern-recognition algorithm
comparable with the full LHCb reconstruction algorithm.Comment: Final draft of WIT proceedings modified according to JINST referee's
comment
A Specialized Processor for Track Reconstruction at the LHC Crossing Rate
We present the results of an R&D study of a specialized processor capable of
precisely reconstructing events with hundreds of charged-particle tracks in
pixel detectors at 40 MHz, thus suitable for processing LHC events at the full
crossing frequency. For this purpose we design and test a massively parallel
pattern-recognition algorithm, inspired by studies of the processing of visual
images by the brain as it happens in nature. We find that high-quality tracking
in large detectors is possible with sub-s latencies when this algorithm is
implemented in modern, high-speed, high-bandwidth FPGA devices. This opens a
possibility of making track reconstruction happen transparently as part of the
detector readout.Comment: Presented by G.Punzi at the conference on "Instrumentation for
Colliding Beam Physics" (INSTR14), 24 Feb to 1 Mar 2014, Novosibirsk, Russia.
Submitted to JINST proceeding
First Evidence of Tris(catecholato)silicate Formation from Hydrolysis of an Alkyl Bis(catecholato)silicate
The hydrolysis of 3-ammoniumpropylbis(catecholato)silicate 1, giving two different silica-based materials containing different amounts of tris(catecholato)silicate, is reported. The latter species can be formed through an attack of catechol to the silicon atom in the pentacoordinate complex, in which the silicon-carbon bond is further activated toward electrophilic proton cleavage. The Knoevenagel reaction was used as a probe in order to test the availability of functional groups on the surface of such materials
Pre-Production and Quality Assurance of the Mu2e Calorimeter Silicon Photomultipliers
The Mu2e electromagnetic calorimeter has to provide precise information on
energy, time and position for 100 MeV electrons. It is composed of 1348
un-doped CsI crystals, each coupled to two large area Silicon Photomultipliers
(SiPMs). A modular and custom SiPM layout consisting of a 32 array of
66 mm UV-extended monolithic SiPMs has been developed to fulfill
the Mu2e calorimeter requirements and a pre-production of 150 prototypes has
been procured by three international firms (Hamamatsu, SensL and Advansid). A
detailed quality assurance process has been carried out on this first batch of
photosensors: the breakdown voltage, the gain, the quenching time, the dark
current and the Photon Detection Efficiency (PDE) have been determined for each
monolithic cell of each SiPMs array. One sample for each vendor has been
exposed to a neutron fluency up to 8.5~~10 1 MeV (Si) eq.
n/cm and a linear increase of the dark current up to tens of mA has been
observed. Others 5 samples for each vendor have undergone an accelerated aging
in order to verify a Mean Time To Failure (MTTF) higher than 10
hours.Comment: NDIP 2017 - New Developments In Photodetection, 3-7 July 2017, Tours
(France
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