The Experts below are selected from a list of 143901 Experts worldwide ranked by ideXlab platform
Sofiaparaskevi Moschou - One of the best experts on this subject based on the ideXlab platform.
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interfacing mhd Single Fluid and kinetic exospheric solar wind models and comparing their energetics
Solar Physics, 2017Co-Authors: Sofiaparaskevi Moschou, Viviane Pierrard, Rony Keppens, Jens PomoellAbstract:An exospheric kinetic solar wind model is interfaced with an observation-driven Single-Fluid magnetohydrodynamic (MHD) model. Initially, a photospheric magnetogram serves as observational input in the Fluid approach to extrapolate the heliospheric magnetic field. Then semi-empirical coronal models are used for estimating the plasma characteristics up to a heliocentric distance of 0.1 AU. From there on, a full MHD model that computes the three-dimensional time-dependent evolution of the solar wind macroscopic variables up to the orbit of Earth is used. After interfacing the density and velocity at the inner MHD boundary, we compare our results with those of a kinetic exospheric solar wind model based on the assumption of Maxwell and Kappa velocity distribution functions for protons and electrons, respectively, as well as with in situ observations at 1 AU. This provides insight into more physically detailed processes, such as coronal heating and solar wind acceleration, which naturally arise from including suprathermal electrons in the model. We are interested in the profile of the solar wind speed and density at 1 AU, in characterizing the slow and fast source regions of the wind, and in comparing MHD with exospheric models in similar conditions. We calculate the energetics of both models from low to high heliocentric distances.
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interfacing mhd Single Fluid and kinetic exospheric solar wind models and comparing their energetics
arXiv: Solar and Stellar Astrophysics, 2017Co-Authors: Sofiaparaskevi Moschou, Viviane Pierrard, Rony Keppens, Jens PomoellAbstract:An exospheric kinetic solar wind model is interfaced with an observation-driven Single Fluid magnetohydrodynamic (MHD) model. Initially, a photospheric magnetogram serves as observational input in the Fluid approach to extrapolate the heliospheric magnetic field. Then semi-empirical coronal models are used for estimating the plasma characteristics up to a heliocentric distance of 0.1AU. From there on a full MHD model which computes the three-dimensional time-dependent evolution of the solar wind macroscopic variables up to the orbit of the Earth is used. After interfacing the density and velocity at the inner MHD boundary, we compare with the results of a kinetic exospheric solar wind model based on the assumption of Maxwell and Kappa velocity distribution functions for protons and electrons respectively, as well as with \textit{in situ} observations at 1AU. This provides insight on more physically detailed processes, such as coronal heating and solar wind acceleration, that naturally arise by inclusion of suprathermal electrons in the model. We are interested in the profile of the solar wind speed and density at 1AU, in characterizing the slow and fast source regions of the wind and in comparing MHD with exospheric models in similar conditions. We calculate the energetics of both models from low to high heliocentric distances.
Jie Chen - One of the best experts on this subject based on the ideXlab platform.
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optimization of th u fuel breeding based on a Single Fluid double zone thorium molten salt reactor
Progress in Nuclear Energy, 2018Co-Authors: P Cong, Yang Zou, J Y Sun, Jie ChenAbstract:Abstract Molten salt reactor (MSR) shows great promise of high thermal-electric conversion efficiency, inherent safety, and on-line reprocessing. Furthermore, fuel breeding can be realized in both thermal and fast spectrum reactors with Th-U fuel cycle, which can make use of the abundant resource of thorium. In order to combine the advantages of high breeding ratio (BR) in fast spectrum and low fissile inventory for criticality in thermal spectrum, a Single-Fluid double-zone thorium-based molten salt reactor (SD-TMSR) core configuration is proposed. First, assemblies in both the inner and the outer zones are optimized by adjusting the ratios of molten salt and graphite with consideration of BR, 233U inventory, double time (DT), and temperature coefficient of reactivity (TCR) at the startup time, aiming to have a minimal DT for fuel breeding and a negative TCR for security. The results show that DT has the optimum value when the ratios of molten salt and graphite in the inner zone and the outer zone are 0.357 and 1.162, respectively. And the TCR can be improved to −2 pcm/K when the side length of the graphite hexagonal prism is 7.5 cm. Then, based on the optimized geometry, the burn-up calculations with a series of on-line reprocessing rates are carried out with a self-developed MSR reprocessing sequence (MSR-RS). The results show that on-line reprocessing is beneficial to the Th-U fuel breeding. When the reprocessing rate is 200 l/d, iso-breeding can be achieved. When the reprocessing rate is 5 m3/d, the performance of Th-U breeding is improved significantly, and only 16 years is needed for the 233U doubling. The results also show that TCR remains negative and inherent safety is satisfied during all the operation time.
Jens Pomoell - One of the best experts on this subject based on the ideXlab platform.
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interfacing mhd Single Fluid and kinetic exospheric solar wind models and comparing their energetics
Solar Physics, 2017Co-Authors: Sofiaparaskevi Moschou, Viviane Pierrard, Rony Keppens, Jens PomoellAbstract:An exospheric kinetic solar wind model is interfaced with an observation-driven Single-Fluid magnetohydrodynamic (MHD) model. Initially, a photospheric magnetogram serves as observational input in the Fluid approach to extrapolate the heliospheric magnetic field. Then semi-empirical coronal models are used for estimating the plasma characteristics up to a heliocentric distance of 0.1 AU. From there on, a full MHD model that computes the three-dimensional time-dependent evolution of the solar wind macroscopic variables up to the orbit of Earth is used. After interfacing the density and velocity at the inner MHD boundary, we compare our results with those of a kinetic exospheric solar wind model based on the assumption of Maxwell and Kappa velocity distribution functions for protons and electrons, respectively, as well as with in situ observations at 1 AU. This provides insight into more physically detailed processes, such as coronal heating and solar wind acceleration, which naturally arise from including suprathermal electrons in the model. We are interested in the profile of the solar wind speed and density at 1 AU, in characterizing the slow and fast source regions of the wind, and in comparing MHD with exospheric models in similar conditions. We calculate the energetics of both models from low to high heliocentric distances.
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interfacing mhd Single Fluid and kinetic exospheric solar wind models and comparing their energetics
arXiv: Solar and Stellar Astrophysics, 2017Co-Authors: Sofiaparaskevi Moschou, Viviane Pierrard, Rony Keppens, Jens PomoellAbstract:An exospheric kinetic solar wind model is interfaced with an observation-driven Single Fluid magnetohydrodynamic (MHD) model. Initially, a photospheric magnetogram serves as observational input in the Fluid approach to extrapolate the heliospheric magnetic field. Then semi-empirical coronal models are used for estimating the plasma characteristics up to a heliocentric distance of 0.1AU. From there on a full MHD model which computes the three-dimensional time-dependent evolution of the solar wind macroscopic variables up to the orbit of the Earth is used. After interfacing the density and velocity at the inner MHD boundary, we compare with the results of a kinetic exospheric solar wind model based on the assumption of Maxwell and Kappa velocity distribution functions for protons and electrons respectively, as well as with \textit{in situ} observations at 1AU. This provides insight on more physically detailed processes, such as coronal heating and solar wind acceleration, that naturally arise by inclusion of suprathermal electrons in the model. We are interested in the profile of the solar wind speed and density at 1AU, in characterizing the slow and fast source regions of the wind and in comparing MHD with exospheric models in similar conditions. We calculate the energetics of both models from low to high heliocentric distances.
P Cong - One of the best experts on this subject based on the ideXlab platform.
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optimization of th u fuel breeding based on a Single Fluid double zone thorium molten salt reactor
Progress in Nuclear Energy, 2018Co-Authors: P Cong, Yang Zou, J Y Sun, Jie ChenAbstract:Abstract Molten salt reactor (MSR) shows great promise of high thermal-electric conversion efficiency, inherent safety, and on-line reprocessing. Furthermore, fuel breeding can be realized in both thermal and fast spectrum reactors with Th-U fuel cycle, which can make use of the abundant resource of thorium. In order to combine the advantages of high breeding ratio (BR) in fast spectrum and low fissile inventory for criticality in thermal spectrum, a Single-Fluid double-zone thorium-based molten salt reactor (SD-TMSR) core configuration is proposed. First, assemblies in both the inner and the outer zones are optimized by adjusting the ratios of molten salt and graphite with consideration of BR, 233U inventory, double time (DT), and temperature coefficient of reactivity (TCR) at the startup time, aiming to have a minimal DT for fuel breeding and a negative TCR for security. The results show that DT has the optimum value when the ratios of molten salt and graphite in the inner zone and the outer zone are 0.357 and 1.162, respectively. And the TCR can be improved to −2 pcm/K when the side length of the graphite hexagonal prism is 7.5 cm. Then, based on the optimized geometry, the burn-up calculations with a series of on-line reprocessing rates are carried out with a self-developed MSR reprocessing sequence (MSR-RS). The results show that on-line reprocessing is beneficial to the Th-U fuel breeding. When the reprocessing rate is 200 l/d, iso-breeding can be achieved. When the reprocessing rate is 5 m3/d, the performance of Th-U breeding is improved significantly, and only 16 years is needed for the 233U doubling. The results also show that TCR remains negative and inherent safety is satisfied during all the operation time.
Viviane Pierrard - One of the best experts on this subject based on the ideXlab platform.
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interfacing mhd Single Fluid and kinetic exospheric solar wind models and comparing their energetics
Solar Physics, 2017Co-Authors: Sofiaparaskevi Moschou, Viviane Pierrard, Rony Keppens, Jens PomoellAbstract:An exospheric kinetic solar wind model is interfaced with an observation-driven Single-Fluid magnetohydrodynamic (MHD) model. Initially, a photospheric magnetogram serves as observational input in the Fluid approach to extrapolate the heliospheric magnetic field. Then semi-empirical coronal models are used for estimating the plasma characteristics up to a heliocentric distance of 0.1 AU. From there on, a full MHD model that computes the three-dimensional time-dependent evolution of the solar wind macroscopic variables up to the orbit of Earth is used. After interfacing the density and velocity at the inner MHD boundary, we compare our results with those of a kinetic exospheric solar wind model based on the assumption of Maxwell and Kappa velocity distribution functions for protons and electrons, respectively, as well as with in situ observations at 1 AU. This provides insight into more physically detailed processes, such as coronal heating and solar wind acceleration, which naturally arise from including suprathermal electrons in the model. We are interested in the profile of the solar wind speed and density at 1 AU, in characterizing the slow and fast source regions of the wind, and in comparing MHD with exospheric models in similar conditions. We calculate the energetics of both models from low to high heliocentric distances.
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interfacing mhd Single Fluid and kinetic exospheric solar wind models and comparing their energetics
arXiv: Solar and Stellar Astrophysics, 2017Co-Authors: Sofiaparaskevi Moschou, Viviane Pierrard, Rony Keppens, Jens PomoellAbstract:An exospheric kinetic solar wind model is interfaced with an observation-driven Single Fluid magnetohydrodynamic (MHD) model. Initially, a photospheric magnetogram serves as observational input in the Fluid approach to extrapolate the heliospheric magnetic field. Then semi-empirical coronal models are used for estimating the plasma characteristics up to a heliocentric distance of 0.1AU. From there on a full MHD model which computes the three-dimensional time-dependent evolution of the solar wind macroscopic variables up to the orbit of the Earth is used. After interfacing the density and velocity at the inner MHD boundary, we compare with the results of a kinetic exospheric solar wind model based on the assumption of Maxwell and Kappa velocity distribution functions for protons and electrons respectively, as well as with \textit{in situ} observations at 1AU. This provides insight on more physically detailed processes, such as coronal heating and solar wind acceleration, that naturally arise by inclusion of suprathermal electrons in the model. We are interested in the profile of the solar wind speed and density at 1AU, in characterizing the slow and fast source regions of the wind and in comparing MHD with exospheric models in similar conditions. We calculate the energetics of both models from low to high heliocentric distances.
