Properties of the propagation of scintillation light in liquid argon (LAr), at λ∼128 nm wavelength, have been experimentally investigated in a dedicated setup at CERN. The speed of scintillation ...photons has been measured for the first time in this medium, refractive index and the Rayleigh scattering are being studied as well. Such measurement provides a key ingredient for the interpretation of data from the current and next generation large mass LAr detectors as those dedicated to the search for rare events such as neutrinos or Dark Matter. Furthermore the improvement on the understanding of the scintillation light propagation represent a benchmark for the multiple theoretical models and simulations for the next generation of detectors which are now based on still incomplete measurements and calculations.
•Measurement of the scintillation light propagation speed in liquid argon.•Optical properties as refractive index and Rayleigh Scattering (λ=128 nm) are derived.•Measurement of interest for LAr-based large scale future experimental setups.•Results can be used to improve current Monte Carlo simulations.
Time series prediction is a remarkable research interest that is widely followed by scientists and researchers. Because many fields include processes of such time series analyses, different kinds of ...approaches, methods, and techniques are employed often in order to achieve alternative ways of prediction. It appears that artificial-intelligence-based solutions have strong potential for providing effective and accurate prediction approaches in even most complicated time series structures. For further details and explanation, this study aims to introduce an alternative artificial-intelligence-based approach to artificial neural networks and cognitive development optimization algorithm, as a recent intelligent optimization technique introduced by the authors. This study aims to predict different kinds of time series by using the introduced system/approach. In this way, it is possible to discuss application potential of the hybrid system and report findings related to its success of prediction. The authors believe that the study provides a good chance to support the literature with an alternative solution approach and see the potential of a newly developed, artificial-intelligence-based optimization algorithm for different applications.
The Deep Underground Neutrino Experiment (DUNE) is the next very large scale neutrino science and proton decay experiment. DUNE will consist of large-scale near and far detectors. The core elements ...of these detector systems are liquid argon Time Projection Chambers (LAr TPCs) and light readout systems. Two prototype far detectors were built and operated at CERN Neutrino Platform and extensive developments are underway for improved and upgraded detectors. In order to evaluate various design alternatives and validate new concepts of light readout related to large-scale LAr detectors, we have performed several experiments with a fifty liter liquid argon TPC at CERN. Among the long list of configurations we probed, study of various wavelength shifters, operation in dual phase mode and Xe and N
2
doping under different scenarios can be listed. Here we report on the details of the various test campaigns and discuss our findings and their impact on the design and operational parameters.
In this study the effects of using defected ground structures (DGS) composed of a complementary split ring resonator (CSRR) and CSRR with dumbbell (CSRR-D) for rectangular microstrip antennas are ...investigated. On this aim, two different antennas, which are Antenna B having CSRR etched DGS and Antenna C having CSRR-D etched DGS are designed and fabricated in comparison with the ordinary rectangular patch antenna, which is Antenna A. In both Antennas B and C, CSRR structures are etched in the same position of the ground planes. On the other hand, another ordinary microstrip antenna, called Antenna D, is designed at resonance frequency of Antenna C. For the characterization; resonance frequencies, voltage standing wave ratios, percentage bandwidths, gains, ka values and gain radiation patterns are investigated both in simulations and experiments. The numerical analyses show that 29.39% and 44.49% electrical size reduction (ESR) ratios are obtained for Antenna B and Antenna C, respectively in comparison to Antenna A. The experimental results verify the ESR ratios with 29.15% and 44.94%. Supporting, Antenna C promises 68.12% physical size reduction (PSR) as it is compared with Antenna D. These results reveal that Antenna C is a good alternative for DGS based microstrip electrically small antennas.
It is generally believed that knowledge of the wall stress distribution could help to find better rupture risk predictors of abdominal aortic aneurysms (AAAs). Although AAA wall stress results from ...combined action between blood, wall and intraluminal thrombus, previously published models for patient-specific assessment of the wall stress predominantly did not include fluid-dynamic effects. In order to facilitate the incorporation of fluid–structure interaction in the assessment of AAA wall stress, in this paper, a method for generating patient-specific hexahedral finite element meshes of the AAA lumen and wall is presented. The applicability of the meshes is illustrated by simulations of the wall stress, blood velocity distribution and wall shear stress in a characteristic AAA. The presented method yields a flexible, semi-automated approach for generating patient-specific hexahedral meshes of the AAA lumen and wall with predefined element distributions. The combined fluid/solid mesh allows for simulations of AAA blood dynamics and AAA wall mechanics and the interaction between the two. The mechanical quantities computed in these simulations need to be validated in a clinical setting, after which they could be included in clinical trials in search of risk factors for AAA rupture.
PDF
