5,106 research outputs found
The new monolithic ASIC of the preshower detector for di-photon measurements in the FASER experiment at CERN
The ForwArd Search ExpeRiment (FASER) is an experiment searching for new
light and weakly-interacting particles at CERN's Large Hadron Collider. FASER
is composed of different sub-detectors, including silicon microstrip detectors,
scintillator counters and an electromagnetic calorimeter. In this paper, a new
preshower detector for the FASER experiment is presented. The new detector,
based on monolithic pixel ASICs, will provide excellent spatial and time
resolutions and a large charge dynamic range. First results from a prototype
chip produced by IHP in 130 nm SiGe BiCMOS technology are shown
Replacing full custom DAQ test system by COTS DAQ components on example of ATLAS SCT readout
A test system developed for ABCN-25 for ATLAS Inner Detector Upgrade is presented. The system is based on commercial off the shelf DAQ components by National Instruments and foreseen to aid in chip characterization and hybrid/module development complementing full custom VME based setups. The key differences from the point of software development are presented, together with guidelines for developing high performance LabVIEW code. Some real-world benchmarks will also be presented together with chip test results. The presented tests show good agreement of test results between the test setups used in different sites, as well as agreement with design specifications of the chip
Electrochemical reduction of carbamazepine in ethanol and water solutions using a glassy carbon electrode
The electrochemical reduction of carbamazepine in ethanol and water using a glassy carbon electrode has been studied. In all experimental conditions of scan rate and concentration of carbamazepine an irreversible cathodic wave was observed by cyclic voltammetry (CV). Electrochemical parameters and a plausible EqC mechanism have been reported from the electrochemical measurements and digital simulation. The values of thermodynamic E1/2 were correlated with solvent polarity parameters that it can be interesting for biological, pharmaceutical and forensic purposes. Limits of Detection (LOD) for DPV are 1.1 and 9.0 g/mL (4.65x10-6 and 3.81x10-5 M) in ethanol and water, respectively. The precision and recoveries obtained for tablets and plasma samples showed that the method could be successfully used for analysis
SO(10) unified models and soft leptogenesis
Motivated by the fact that, in some realistic models combining SO(10) GUTs
and flavour symmetries, it is not possible to achieve the required baryon
asymmetry through the CP asymmetry generated in the decay of right-handed
neutrinos, we take a fresh look on how deep this connection is in SO(10). The
common characteristics of these models are that they use the see-saw with
right-handed neutrinos, predict a normal hierarchy of masses for the neutrinos
observed in oscillating experiments and in the basis where the right-handed
Majorana mass is diagonal, the charged lepton mixings are tiny.
In addition these models link the up-quark Yukawa matrix to the neutrino
Yukawa matrix Y^\nu with the special feature of Y^\nu_{11}-> 0 Using this
condition, we find that the required baryon asymmetry of the Universe can be
explained by the soft leptogenesis using the soft B parameter of the second
lightest right-handed neutrino whose mass turns out to be around 10^8 GeV. It
is pointed out that a natural way to do so is to use no-scale supergravity
where the value of B ~1 GeV is set through gauge-loop corrections.Comment: 26 pages, 2 figures. Added references, new appendix of a relevant fit
and improved comment
CP and Lepton-Number Violation in GUT Neutrino Models with Abelian Flavour Symmetries
We study the possible magnitudes of CP and lepton-number-violating quantities
in specific GUT models of massive neutrinos with different Abelian flavour
groups, taking into account experimental constraints and requiring successful
leptogenesis. We discuss SU(5) and flipped SU(5) models that are consistent
with the present data on neutrino mixing and upper limits on the violations of
charged-lepton flavours and explore their predictions for the CP-violating
oscillation and Majorana phases. In particular, we discuss string-derived
flipped SU(5) models with selection rules that modify the GUT structure and
provide additional constraints on the operators, which are able to account for
the magnitudes of some of the coefficients that are often set as arbitrary
parameters in generic Abelian models.Comment: 30 pages, 6 figure
Time resolution and power consumption of a monolithic silicon pixel prototype in SiGe BiCMOS technology
SiGe BiCMOS technology can be used to produce ultra-fast, low-power silicon
pixel sensors that provide state-of-the-art time resolution even without an
internal gain mechanism. The development of such sensors requires the
identification of the main factors that may degrade the timing performance and
the characterisation of the dependance of the sensor time resolution on the
amplifier power consumption. Measurements with a source of
a prototype sensor produced in SG13G2 technology from IHP Microelectronics,
shows a time resolution of 140 ps at an amplifier current of 7 A and 45 ps at higher power consumption. A full simulation shows that the
resolution on the measurement of the signal time-over-threshold, used to
correct for time walk, is the main factor affecting the timing performance
HV/HR-CMOS sensors for the ATLAS upgradeâconcepts and test chip results
In order to extend its discovery potential, the Large Hadron Collider (LHC) will have a major upgrade (Phase II Upgrade) scheduled for 2022. The LHC after the upgrade, called High-Luminosity LHC (HL-LHC), will operate at a nominal leveled instantaneous luminosity of 5Ă 1034 cmâ2 sâ1, more than twice the expected Phase I . The new Inner Tracker needs to cope with this extremely high luminosity. Therefore it requires higher granularity, reduced material budget and increased radiation hardness of all components. A new pixel detector based on High Voltage CMOS (HVCMOS) technology targeting the upgraded ATLAS pixel detector is under study. The main advantages of the HVCMOS technology are its potential for low material budget, use of possible cheaper interconnection technologies, reduced pixel size and lower cost with respect to traditional hybrid pixel detector. Several first prototypes were produced and characterized within ATLAS upgrade R&D effort, to explore the performance and radiation hardness of this technology.
In this paper, an overview of the HVCMOS sensor concepts is given. Laboratory tests and irradiation tests of two technologies, HVCMOS AMS and HVCMOS GF, are also given
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