The Experts below are selected from a list of 6786 Experts worldwide ranked by ideXlab platform
R. Iuppa - One of the best experts on this subject based on the ideXlab platform.
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observation of the cosmic ray moon Shadowing Effect with the argo ybj experiment
Physical Review D, 2011Co-Authors: R. Iuppa, G Di SciascioAbstract:Cosmic rays are hampered by the Moon and a deficit in its direction is expected (the so-called Moon shadow). The Moon shadow is an important tool to determine the performance of an air shower array. In fact, the displacement of the shadow center, due to the bending Effect of the Geomagnetic field on the propagation of cosmic rays, allows to set the energy scale of the primary particles inducing the showers observed by the detector. The shape of the shadow permits to determine the detector point spread function. The position of the deficit at high energy allows evaluating its pointing accuracy. Here we present the observation of the cosmic ray Moon Shadowing Effect carried out by the ARGO-YBJ experiment (Yangbajing Cosmic Ray Laboratory, Tibet, P.R. China, 4300 m a.s.l., 606 g/cm 2 ) in the multi-TeV energy region with high statistical significance (70 standard deviations). By means of an accurate Monte Carlo simulation of the cosmic rays propagation in the Earth-Moon system we have studied the role of the Geomagnetic field and of the detector point spread function on the observed shadow.
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observation of the cosmic ray moon Shadowing Effect with the argo ybj experiment
arXiv: High Energy Astrophysical Phenomena, 2011Co-Authors: R. Iuppa, G Di SciascioAbstract:Cosmic rays are hampered by the Moon and a deficit in its direction is expected (the so-called \emph{Moon shadow}). The Moon shadow is an important tool to determine the performance of an air shower array. In fact, the displacement of the shadow center, due to the bending Effect of the Geomagnetic field on the propagation of cosmic rays, allows to set the energy scale of the primary particles inducing the showers observed by the detector. The shape of the shadow permits to determine the detector point spread function. The position of the deficit at high energy allows evaluating its pointing accuracy. Here we present the observation of the cosmic ray Moon Shadowing Effect carried out by the ARGO-YBJ experiment (Yangbajing Cosmic Ray Laboratory, Tibet, P.R. China, 4300 m a.s.l., 606 g/cm$^2$) in the multi-TeV energy region with high statistical significance (70 standard deviations). By means of an accurate Monte Carlo simulation of the cosmic rays propagation in the Earth-Moon system we have studied the role of the Geomagnetic field and of the detector point spread function on the observed shadow.
G Di Sciascio - One of the best experts on this subject based on the ideXlab platform.
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observation of the cosmic ray moon Shadowing Effect with the argo ybj experiment
Physical Review D, 2011Co-Authors: R. Iuppa, G Di SciascioAbstract:Cosmic rays are hampered by the Moon and a deficit in its direction is expected (the so-called Moon shadow). The Moon shadow is an important tool to determine the performance of an air shower array. In fact, the displacement of the shadow center, due to the bending Effect of the Geomagnetic field on the propagation of cosmic rays, allows to set the energy scale of the primary particles inducing the showers observed by the detector. The shape of the shadow permits to determine the detector point spread function. The position of the deficit at high energy allows evaluating its pointing accuracy. Here we present the observation of the cosmic ray Moon Shadowing Effect carried out by the ARGO-YBJ experiment (Yangbajing Cosmic Ray Laboratory, Tibet, P.R. China, 4300 m a.s.l., 606 g/cm 2 ) in the multi-TeV energy region with high statistical significance (70 standard deviations). By means of an accurate Monte Carlo simulation of the cosmic rays propagation in the Earth-Moon system we have studied the role of the Geomagnetic field and of the detector point spread function on the observed shadow.
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observation of the cosmic ray moon Shadowing Effect with the argo ybj experiment
arXiv: High Energy Astrophysical Phenomena, 2011Co-Authors: R. Iuppa, G Di SciascioAbstract:Cosmic rays are hampered by the Moon and a deficit in its direction is expected (the so-called \emph{Moon shadow}). The Moon shadow is an important tool to determine the performance of an air shower array. In fact, the displacement of the shadow center, due to the bending Effect of the Geomagnetic field on the propagation of cosmic rays, allows to set the energy scale of the primary particles inducing the showers observed by the detector. The shape of the shadow permits to determine the detector point spread function. The position of the deficit at high energy allows evaluating its pointing accuracy. Here we present the observation of the cosmic ray Moon Shadowing Effect carried out by the ARGO-YBJ experiment (Yangbajing Cosmic Ray Laboratory, Tibet, P.R. China, 4300 m a.s.l., 606 g/cm$^2$) in the multi-TeV energy region with high statistical significance (70 standard deviations). By means of an accurate Monte Carlo simulation of the cosmic rays propagation in the Earth-Moon system we have studied the role of the Geomagnetic field and of the detector point spread function on the observed shadow.
łukasz Januszkiewicz - One of the best experts on this subject based on the ideXlab platform.
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analysis of human body Shadowing Effect on wireless sensor networks operating in the 2 4 ghz band
Sensors, 2018Co-Authors: łukasz JanuszkiewiczAbstract:Miniaturized wireless sensors are designed to run on limited power resources, requiring minimization of transmit power and lowering of the fade margin in the link budget. One factor that has an important impact on wireless sensor network design is path loss between the transmitter and the receiver. This paper presents an analysis of the influence of human bodies on path loss in the 2.4 GHz band, which is commonly used for wireless sensor networks. The Effect of body Shadowing was first analyzed in full wave computer simulations using the finite-difference time-domain method. Due to the high numerical burden, the simulations were limited to only a small region around the human body. To analyze the performance of networks in larger indoor environments, a human body model is proposed that can be used for simulations with a ray-based computer program. The proposed model of human body is the main contribution of this paper. It was used to analyze the body Shadowing Effect in a typical indoor environment. The results were found to be in good agreement with measurements.
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model for ray based utd simulations of the human body Shadowing Effect in 5g wireless systems
International Journal of Antennas and Propagation, 2018Co-Authors: łukasz JanuszkiewiczAbstract:Shadowing Effects caused by the obstructing presence of a human body can result in increased path loss in indoor wireless systems. This paper proposes a simplified model of a human body for use in ray-tracing simulations of indoor wireless communication systems based on the uniform theory of diffraction (UTD). The human body Shadowing Effect was first investigated using measurements and computer simulations employing the finite-difference time-domain method (FDTD). Based on the results, a human body model was elaborated for use in ray-based Remcom XGtd software. The model was developed for the 3.6 GHz band, which has been allocated for 5G wireless systems in many countries.
A Cavaleiro - One of the best experts on this subject based on the ideXlab platform.
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reduced atomic Shadowing in hipims role of the thermalized metal ions
Applied Surface Science, 2018Co-Authors: J C Oliveira, Fabio Ferreira, Andre Anders, A CavaleiroAbstract:Abstract In magnetron sputtering, the ability to tailor film properties depends primarily on the control of the flux of particles impinging on the growing film. Among deposition mechanisms, the Shadowing Effect leads to the formation of a rough surface and a porous, columnar microstructure. Re-sputtered species may be re-deposited in the valleys of the films surface and thereby contribute to a reduction of roughness and to fill the underdense regions. Both Effects are non-local and they directly compete to shape the final properties of the deposited films. Additional control of the bombarding flux can be obtained by ionizing the sputtered flux, because ions can be controlled with respect to their energy and impinging direction, such as in High-Power Impulse Magnetron Sputtering (HiPIMS). In this work, the relation between ionization of the sputtered species and thin film properties is investigated in order to identify the mechanisms which Effectively influence the Shadowing Effect in Deep Oscillation Magnetron Sputtering (DOMS), a variant of HiPIMS. The properties of two Cr films deposited using the same averaged target power by d.c. magnetron sputtering and DOMS have been compared. Additionally, the angle distribution of the Cr species impinging on the substrate was simulated using Monte Carlo-based programs while the energy distribution of the energetic particles bombarding the substrate was evaluated by energy-resolved mass analysis. It was found that the acceleration of the thermalized chromium ions at the substrate sheath in DOMS significantly reduces the high angle component of their impinging angle distribution and, thus, efficiently reduces atomic Shadowing. Therefore, a high degree of ionization in HiPIMS results in almost Shadowing Effect-free film deposition and allows us to deposit dense and compact films without the need of high energy particle bombardment during growth.
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crn thin films deposited by hipims in doms mode
Surface & Coatings Technology, 2016Co-Authors: Fabio Ferreira, J C Oliveira, A CavaleiroAbstract:Abstract It is well known that increasing the energy of the bombardment species, whether by using a bias or an additional ion source in direct current magnetron sputtering (DCMS) or by optimizing the deposition conditions in mid-frequency bipolar magnetron sputtering, enables us to tailor the properties of the CrN thin films. In the last fifteen years, several magnetron sputtering deposition methods have been developed which have aimed to produce highly ionized fluxes of sputtered material, thus enabling increased control over the energy and impinging angle distributions of the bombarding species. In this study, CrN thin films were deposited by deep oscillation magnetron sputtering (DOMS), a variant of High-power Impulse Magnetron Sputtering (HiPIMS), in order to study the Effect of the additional control of the energetic ion bombardment on the film properties. The structural properties of the CrN films (lattice parameter and preferred orientation) showed that an intense energetic bombardment is always present in the DOMS deposition irrespective of the deposition conditions. This energetic bombardment was attributed to energetic N neutrals which are reflected at the target surface upon impingement of N2+ ions. A change from a columnar growth mode to a featureless one was observed with an increasing peak power at both 0.3 and 0.7 Pa. At the same time, the hardness of the films increased from 21–22 GPa to 28–29 GPa. This transformation was attributed to the increasing fraction of ionized sputtered species with increasing peak power. The columnar growth is interrupted by preventing the Shadowing Effect, i.e., due to the higher ionization fraction at higher pressure and/or peak power, rather than by overcoming the Shadowing Effect by using more energetic bombardment.
P. Bernardini - One of the best experts on this subject based on the ideXlab platform.
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Moon and Sun Shadowing Effect in the MACRO detector
Astroparticle Physics, 2003Co-Authors: M. Ambrosio, R. Antolini, A. Baldini, G. C. Barbarino, Barry C. Barish, G. Battistoni, Y. Becherini, Roberto Bellotti, C. Bemporad, P. BernardiniAbstract:Abstract Using data collected by the MACRO experiment from 1989 to the end of its operations in 2000, we have studied in the underground muon flux the Shadowing Effects due to both the Moon and the Sun. We have observed the shadow cast by the Moon at its apparent position with a significance of 6.5 σ . The Moon Shadowing Effect has been used to verify the pointing capability of the detector and to determine the instrument resolution for the search of muon excesses from any direction of the celestial sphere. The dependence of the Effect on the geomagnetic field is clearly shown by splitting the data sample in day and night observations. The Sun shadow, observed with a significance of 4.6 σ is displaced by about 0.6° from its apparent position. In this case however the explanation resides in the configuration of the Solar and Interplanetary Magnetic Fields, which affect the propagation of cosmic ray particles between the Sun, and the Earth. The displacement of the Sun shadow with respect to the real Sun position has been used to establish an upper limit on the antimatter flux in cosmic rays of about 48% at 68% c.l. and primary energies of about 20 TeV.