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中国科学技术大学核科学技术学院等离子体物理与聚变工程系的磁测量实验课题组，与中科院等离子体物理研究所团队紧密合作，首次在EAST超导托卡马克装置上测量到内扭曲模的磁扰动幅度分布，并进一步通过磁涨落和电子温度涨落的关联，确定了磁不稳定性诱发的发电机（Dynamo）效应的大小和方向，表明该发电机效应对磁约束聚变装置安全运行密切相关的电流分布控制起重要作用。该工作以“Fluctuation-induce...
Supercriticality to subcriticality in dynamo transitions
Supercriticality to subcriticality dynamo transitions Fluid Dynamics
2012/4/20
In this paper, we present a three-mode dynamo model which describes both supercritical and subcritical dynamo transitions. The nature of dynamo transition changes from supercritical to subcritical as ...
Nonlinear dynamo in a short Taylor-Couette setup
Finite elements Magnetohydrodynamics Taylor-Couette dynamo action
2012/4/18
It is numerically demonstrated by means of a magnetohydrodynamics code that a short Taylor-Couette setup with a body force can sustain dynamo action. The magnetic threshold is comparable to what is us...
Dipole Collapse and Dynamo Waves in Global Direct Numerical Simulations
Dipole Collapse Dynamo Waves Global Direct Numerical Simulations
2012/2/23
Magnetic fields of low-mass stars and planets are thought to originate from self-excited dynamo action in their convective interiors. Observations reveal a variety of field topologies ranging from lar...
Helicity and dynamo action in magnetized stellar radiation zones
magnetohydrodynamics (MHD) – instabilities – stars: magnetic fi elds – stars: interiors
2011/10/8
Helicity and \alpha effect driven by the nonaxisymmetric Tayler instability of toroidal magnetic fields in stellar radiation zones are computed. In the linear approximation a purely toroidal field alw...
Scaling and intermittency in incoherent α-shear dynamo
Dynamo – magnetic fi elds – MHD – turbulence
2011/10/8
We consider mean-field dynamo models with fluctuating \alpha effect, both with and without shear. The \alpha effect is chosen to be Gaussian white noise with zero mean and given covariance. We show an...
Scaling and intermittency in incoherent α-shear dynamo
Dynamo magnetic fields MHD turbulence
2011/8/17
Abstract: We consider mean-field dynamo models with fluctuating \alpha effect, both with and without shear. The \alpha effect is chosen to be Gaussian white noise with zero mean and given covariance. ...
A dynamo driven by zonal jets at the upper surface: applications to giant planets
giant planets upper surface
2011/9/1
We present a dynamo mechanism arising from the presence of barotropically unstable zonal jet currents in a spherical shell. The shear instability of the zonal flow develops in the form of a global Ros...
Kinematic dynamo simulations of von Kármán flows: application to the VKS experiment
von Kármán flows Kinematic dynamo simulations VKS experiment
2011/7/7
The VKS experiment has evidenced dynamo action in a highly turbulent liquid sodium von K\'arm\'an flow [R. Monchaux et al., Phys. Rev. Lett. {\bf 98}, 044502 (2007)]. However, the existence and the on...
Comment on paper by L. M. Malyshkin and S. Boldyrev, "Magnetic dynamo action at low magnetic Prandtl numbers", PRL 105, 215002 (2010)
"Magnetic dynamo action low magnetic Prandtl numbers"
2010/12/28
Is the scaling, / Rm1/2, for the growth rate of small-scale dynamo instability at low magnetic Prandtl numbers and large magnetic Reynolds numbers, Rm, valid in the vicinity of the threshold?Our ana...
Using the magnetohydrodynamic (MHD) description, we develop a nonlinear dynamo model that couples the evolution of the large scale magnetic field with turbulent dynamics of the plasma at small scale b...
Main-sequence massive stars possess convective cores that likely harbor strong dy-namo action. To assess the role of core convection in building magnetic fields within these stars, we employ the 3-D a...
In this work we investigate numerically the kinematic dynamo driven by spherical Couette flow. We calculate both 2D and 3D flows, different global rotation rates, opposite directions of differential ...
Global dynamo simulations solving the equations of magnetohydrodynamics (MHD) have been a tool of astrophysicists who try to understand the magnetism of the Sun for several decades now. During recent ...
Dynamo generated field emergence through recurrent plasmoid ejections
Solar and Stellar Astrophysics (astro-ph.SR)
2010/12/23
Magnetic buoyancy is believed to drive the transport of magnetic flux tubes from the convection zone to the surface of the Sun. The magnetic fields form twisted loop-like structures in the solar atmos...