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V M Nakariakov - One of the best experts on this subject based on the ideXlab platform.
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north south asymmetry in the Magnetic Deflection of polar coronal hole jets
Astronomy and Astrophysics, 2015Co-Authors: Giuseppe Nistico, G Zimbardo, S Patsourakos, V Bothmer, V M NakariakovAbstract:Context: Measurements of the sunspots area, of the Magnetic field in the interplanetary medium, and of the heliospheric current sheet (HCS) position, reveal a possible north-south (N-S) asymmetry in the Magnetic field of the Sun. This asymmetry could cause the bending of the HCS of the order of 5–10 deg in the southward direction, and it appears to be a recurrent characteristic of the Sun during the minima of solar activity. Aims: We study the N-S asymmetry as inferred from measurements of the Deflection of polar coronal hole jets when they propagate throughout the corona. Methods: Since the corona is an environment where the Magnetic pressure is greater than the kinetic pressure (β ≪ 1), we can assume that the Magnetic field controls the dynamics of plasma. On average, jets follow Magnetic field lines during their propagation, highlighting their local direction. We measured the position angles at 1 R⊙ and at 2 R⊙ of 79 jets, based on the Solar TErrestrial RElations Observatory (STEREO) ultraviolet and white-light coronagraph observations during the solar minimum period March 2007–April 2008. The average jet Deflection is studied both in the plane perpendicular to the line of sight and, for a reduced number of jets, in 3D space. The observed jet Deflection is studied in terms of an axisymmetric Magnetic field model comprising dipole (g1), quadrupole (g2), and esapole (g3) moments. Results: We found that the propagation of the jets is not radial, which is in agreement with the Deflection due to Magnetic field lines. Moreover, the amount of the Deflection is different between jets over the north and those from the south pole. A comparison of jet Deflections and field line tracing shows that a ratio g2/g1 ≃ −0.5 for the quadrupole and a ratio g3/g1 ≃ 1.6–2.0 for the esapole can describe the field. The presence of a non-negligible quadrupole moment confirms the N-S asymmetry of the solar Magnetic field for the considered period. Conclusions: We find that the Magnetic Deflection of jets is larger in the north than in the south of the order of 25–40%, with an asymmetry that is consistent with a southward Deflection of the heliospheric current sheet of the order of 10 deg, consistent with that inferred from other independent datasets and instruments.
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north south asymmetry in the Magnetic Deflection of polar coronal hole jets
arXiv: Solar and Stellar Astrophysics, 2015Co-Authors: Giuseppe Nistico, G Zimbardo, S Patsourakos, V Bothmer, V M NakariakovAbstract:Measurements of the Magnetic field in the interplanetary medium, of the sunspots area, and of the heliospheric current sheet position, reveal a possible North-South asymmetry in the Magnetic field of the Sun. We study the North-South asymmetry as inferred from measurements of the Deflection of polar coronal hole jets when they propagate throughout the corona. Since the corona is an environment where the Magnetic pressure is greater than the kinetic pressure, we can assume that Magnetic field controls the dynamics of plasma. On average, jets during their propagation follow the Magnetic field lines, highlighting its local direction. The average jet Deflection is studied both in the plane perpendicular to the line of sight, and, for a reduced number of jets, in three dimensional space. The observed jet Deflection is studied in terms of an axisymmetric Magnetic field model comprising dipole We measured the position angles at 1 rs and at 2 rs of the 79 jets from the catalogue of Nistico et al 2009., based on the STEREO ultraviolet and white-light coronagraph observations during the solar minimum period March 2007-April 2008. We found that the propagation is not radial, in agreement with the Deflection due to Magnetic field lines. Moreover, the amount of the Deflection is different between jets over the north and those from the south pole. Comparison of jet Deflections and field line tracing shows that a ratio g2/g1 ~ -0.5 for the quadrupole and a ratio g3/g1 ~ 1.6-2.0 for the esapole can describe the field. The presence of a non-negligible quadrupole moment. We find that the Magnetic Deflection of jets is larger in the North than in the South of the order of 25-40%, with an asymmetry which is consistent with a southward Deflection of the heliospheric current sheet of the order of 10 deg, consistent with that inferred from other, independent, datasets and instruments.
Bartłomiej Szafran - One of the best experts on this subject based on the ideXlab platform.
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multisubband transport and Magnetic Deflection of fermi electron trajectories in three terminal junctions and rings
Journal of Physics: Condensed Matter, 2012Co-Authors: M R Poniedzialek, Bartłomiej SzafranAbstract:We study the electron transport in three terminal junctions and quantum rings looking for the classical Deflection of electron trajectories in the presence of intersubband scattering. We indicate that although the Aharonov?Bohm oscillations and the Lorentz force effects co-exist in the low subband transport, for higher Fermi energies a simultaneous observation of both effects is difficult and calls for carefully formed structures. In particular, in quantum rings with channels wider than the input lead the Lorentz force is well resolved but the Aharonov?Bohm periodicity is lost in chaotic scattering events. In quantum rings with equal lengths of the channels and T-shaped junctions the Aharonov?Bohm oscillations are distinctly periodic but the Lorentz force effects are not well pronounced. We find that systems with wedge-shaped junctions allow for observation of both the periodic Aharonov?Bohm oscillations and the Magnetic Deflection.
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multisubband transport and Magnetic Deflection of fermi electron trajectories in three terminal junctions and rings
arXiv: Mesoscale and Nanoscale Physics, 2011Co-Authors: M R Poniedzialek, Bartłomiej SzafranAbstract:We study the electron transport in three terminal junctions and quantum rings looking for the classical Deflection of electron trajectories in presence of intersubband scattering. We indicate that although the Aharonov-Bohm oscillations and the Lorentz force effects co-exist in the low subband transport, for higher Fermi energies a simultaneous observation of the both effects is difficult and calls for carefully formed structures. In particular, in quantum rings with channels wider than the input lead the Lorentz force is well resolved but the Aharonov-Bohm periodicity is lost in chaotic scattering events. In quantum rings with equal length of the channels and $T$-shaped junctions the Aharonov-Bohm oscillations are distinctly periodic but the Lorentz force effects are not well pronounced. We find that systems with the wedge shaped junctions allow for observation of both the periodic Aharonov-Bohm oscillations and the Magnetic Deflection.
M R Poniedzialek - One of the best experts on this subject based on the ideXlab platform.
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multisubband transport and Magnetic Deflection of fermi electron trajectories in three terminal junctions and rings
Journal of Physics: Condensed Matter, 2012Co-Authors: M R Poniedzialek, Bartłomiej SzafranAbstract:We study the electron transport in three terminal junctions and quantum rings looking for the classical Deflection of electron trajectories in the presence of intersubband scattering. We indicate that although the Aharonov?Bohm oscillations and the Lorentz force effects co-exist in the low subband transport, for higher Fermi energies a simultaneous observation of both effects is difficult and calls for carefully formed structures. In particular, in quantum rings with channels wider than the input lead the Lorentz force is well resolved but the Aharonov?Bohm periodicity is lost in chaotic scattering events. In quantum rings with equal lengths of the channels and T-shaped junctions the Aharonov?Bohm oscillations are distinctly periodic but the Lorentz force effects are not well pronounced. We find that systems with wedge-shaped junctions allow for observation of both the periodic Aharonov?Bohm oscillations and the Magnetic Deflection.
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multisubband transport and Magnetic Deflection of fermi electron trajectories in three terminal junctions and rings
arXiv: Mesoscale and Nanoscale Physics, 2011Co-Authors: M R Poniedzialek, Bartłomiej SzafranAbstract:We study the electron transport in three terminal junctions and quantum rings looking for the classical Deflection of electron trajectories in presence of intersubband scattering. We indicate that although the Aharonov-Bohm oscillations and the Lorentz force effects co-exist in the low subband transport, for higher Fermi energies a simultaneous observation of the both effects is difficult and calls for carefully formed structures. In particular, in quantum rings with channels wider than the input lead the Lorentz force is well resolved but the Aharonov-Bohm periodicity is lost in chaotic scattering events. In quantum rings with equal length of the channels and $T$-shaped junctions the Aharonov-Bohm oscillations are distinctly periodic but the Lorentz force effects are not well pronounced. We find that systems with the wedge shaped junctions allow for observation of both the periodic Aharonov-Bohm oscillations and the Magnetic Deflection.
Zhixiong Liu - One of the best experts on this subject based on the ideXlab platform.
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Electron optical aberration calculations in a homogeneous Magnetic Deflection system with curved axis at extra-large defection angles
IEEE Transactions on Electron Devices, 1996Co-Authors: Jiye Ximen, Linsu Tong, Zhixiong LiuAbstract:In the authors' previous paper, variational Deflection aberration theory has been developed for nonhomogeneous Magnetic Deflection systems with curved axes at extra-large Deflection angles. Based on the variational Deflection aberration theory, a Magnetic Deflection system consisting of a homogeneous Deflection field and a homogeneous sextupole field has been further investigated in the present paper. For such a Magnetic Deflection system, both the Gaussian trajectory and all second- and third-order aberrations have been calculated analytically and been expressed by algebraic-trigonometric formulae suitable for computer computations. It is to be expected that the present research and computational results may be useful in designing high-performance Magnetic Deflection systems for high-definition television color picture tubes with self-convergence.
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A unified aberration theory for Magnetic Deflection systems with rectilinear or curvilinear axes
IEEE Transactions on Electron Devices, 1996Co-Authors: Jiye Ximen, Linsu Tong, Zhixiong LiuAbstract:A unified Deflection aberration theory has been further developed for Magnetic Deflection systems with curvilinear or rectilinear axes. By using variational method, primary-order Deflection aberrations with respect to curvilinear or rectilinear axis can be universally calculated by means of gradient operations on eikonal (the function of optical length). Conventional pure-order rectilinear-axis theory can be derived from a curvilinear axis eikonal of mixed-order in the rectilinear limit. By introducing general aberration integration functions in terms of mathematical operators, all primary-order Deflection aberrations have been explicitly expressed in compact formulae suitable for computer computations. It is to be expected that the unified Deflection aberration theory may be useful in designing high-quality Magnetic Deflection systems for high-definition television color picture tubes.
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Variational aberration theory for Magnetic Deflection systems with curved axes at extra-large angles
IEEE Transactions on Electron Devices, 1995Co-Authors: Jiye Ximen, Linsu Tong, Zhixiong LiuAbstract:Variational Deflection aberration theory has been further developed for Deflection systems with curved axes at extra-large Deflection angles (up to 120/spl deg/). The variational method allows us to calculate second- and third-order Deflection aberrations with respect to a curved axis by means of gradient operations on eikonal (the function of optical length). All second- and third-order Deflection aberrations have been explicitly expressed in compact and appropriate formulae suitable for computer computations. It is to be expected that the variational Deflection aberration theory may be useful in designing high-quality Magnetic Deflection systems for high-Deflection television color picture tubes. >
Giuseppe Nistico - One of the best experts on this subject based on the ideXlab platform.
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north south asymmetry in the Magnetic Deflection of polar coronal hole jets
Astronomy and Astrophysics, 2015Co-Authors: Giuseppe Nistico, G Zimbardo, S Patsourakos, V Bothmer, V M NakariakovAbstract:Context: Measurements of the sunspots area, of the Magnetic field in the interplanetary medium, and of the heliospheric current sheet (HCS) position, reveal a possible north-south (N-S) asymmetry in the Magnetic field of the Sun. This asymmetry could cause the bending of the HCS of the order of 5–10 deg in the southward direction, and it appears to be a recurrent characteristic of the Sun during the minima of solar activity. Aims: We study the N-S asymmetry as inferred from measurements of the Deflection of polar coronal hole jets when they propagate throughout the corona. Methods: Since the corona is an environment where the Magnetic pressure is greater than the kinetic pressure (β ≪ 1), we can assume that the Magnetic field controls the dynamics of plasma. On average, jets follow Magnetic field lines during their propagation, highlighting their local direction. We measured the position angles at 1 R⊙ and at 2 R⊙ of 79 jets, based on the Solar TErrestrial RElations Observatory (STEREO) ultraviolet and white-light coronagraph observations during the solar minimum period March 2007–April 2008. The average jet Deflection is studied both in the plane perpendicular to the line of sight and, for a reduced number of jets, in 3D space. The observed jet Deflection is studied in terms of an axisymmetric Magnetic field model comprising dipole (g1), quadrupole (g2), and esapole (g3) moments. Results: We found that the propagation of the jets is not radial, which is in agreement with the Deflection due to Magnetic field lines. Moreover, the amount of the Deflection is different between jets over the north and those from the south pole. A comparison of jet Deflections and field line tracing shows that a ratio g2/g1 ≃ −0.5 for the quadrupole and a ratio g3/g1 ≃ 1.6–2.0 for the esapole can describe the field. The presence of a non-negligible quadrupole moment confirms the N-S asymmetry of the solar Magnetic field for the considered period. Conclusions: We find that the Magnetic Deflection of jets is larger in the north than in the south of the order of 25–40%, with an asymmetry that is consistent with a southward Deflection of the heliospheric current sheet of the order of 10 deg, consistent with that inferred from other independent datasets and instruments.
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north south asymmetry in the Magnetic Deflection of polar coronal hole jets
arXiv: Solar and Stellar Astrophysics, 2015Co-Authors: Giuseppe Nistico, G Zimbardo, S Patsourakos, V Bothmer, V M NakariakovAbstract:Measurements of the Magnetic field in the interplanetary medium, of the sunspots area, and of the heliospheric current sheet position, reveal a possible North-South asymmetry in the Magnetic field of the Sun. We study the North-South asymmetry as inferred from measurements of the Deflection of polar coronal hole jets when they propagate throughout the corona. Since the corona is an environment where the Magnetic pressure is greater than the kinetic pressure, we can assume that Magnetic field controls the dynamics of plasma. On average, jets during their propagation follow the Magnetic field lines, highlighting its local direction. The average jet Deflection is studied both in the plane perpendicular to the line of sight, and, for a reduced number of jets, in three dimensional space. The observed jet Deflection is studied in terms of an axisymmetric Magnetic field model comprising dipole We measured the position angles at 1 rs and at 2 rs of the 79 jets from the catalogue of Nistico et al 2009., based on the STEREO ultraviolet and white-light coronagraph observations during the solar minimum period March 2007-April 2008. We found that the propagation is not radial, in agreement with the Deflection due to Magnetic field lines. Moreover, the amount of the Deflection is different between jets over the north and those from the south pole. Comparison of jet Deflections and field line tracing shows that a ratio g2/g1 ~ -0.5 for the quadrupole and a ratio g3/g1 ~ 1.6-2.0 for the esapole can describe the field. The presence of a non-negligible quadrupole moment. We find that the Magnetic Deflection of jets is larger in the North than in the South of the order of 25-40%, with an asymmetry which is consistent with a southward Deflection of the heliospheric current sheet of the order of 10 deg, consistent with that inferred from other, independent, datasets and instruments.
