Small-Scale-Field Dynamo.
نویسندگان
چکیده
منابع مشابه
Can the turbulent galactic dynamo generate large - scale magnetic fields ?
Large-scale magnetic fields in galaxies are thought to be generated by a turbulent dynamo. However the same turbulence also leads to a small-scale dynamo which generates magnetic noise at a more rapid rate. The efficiency of the large-scale dynamo depends on how this noise saturates. We examine this issue taking into account ambipolar drift, which obtains in a galaxy with significant neutral ga...
متن کاملRecent Developments in Magnetic Dynamo Theory
Two spectral regimes of magnetic field amplification in magnetohydrodynamic (MHD) flows can be distinguished by the scale on which fields are amplified relative to the primary forcing scale of the turbulence. For field amplification at or below the forcing scale, the amplification can be called a “small scale dynamo.” For amplification at and above the forcing scale the process can be called a ...
متن کاملConference Summary: Three-Dimensional Explosions
1.2 Dynamo Theory and Saturation Fields There has been a major breakthrough in the conceptual understanding of astrophysical dynamos in the last few years. In traditional mean field dynamo theory, the turbulent velocity field that drives the “alpha” portion of the α−Ω dynamo was specified and held fixed. A weakness of the original theory was that the turbulent velocity field cannot be constant....
متن کاملThe Origin of Large Scale Galactic Magnetic Fields
Magnetic fields correlated on several kiloparsec scales are seen in spiral galaxies. Their origin could be due to the winding up of a primordial cosmological field or due to amplification of a small seed field by a turbulent galactic dynamo. Both options have difficulties: There is no known battery mechanism for producing the required primordial field. Equally the turbulent dynamo may self dest...
متن کاملShell to shell energy transfer in magnetohydrodynamic dynamo simulations
We study the transfer of energy between different scales for forced three-dimensional MHD turbulent flows in the kinematic dynamo regime. Two different forces are examined: a non-helical Taylor Green flow with magnetic Prandtl number PM = 0.4, and a helical ABC flow with PM = 1. This analysis allows us to examine which scales of the velocity flow are responsible for dynamo action, and which sca...
متن کاملFate of Alpha Dynamos at Large Rm.
At the heart of today's solar magnetic field evolution models lies the alpha dynamo description. In this work, we investigate the fate of alpha dynamos as the magnetic Reynolds number Rm is increased. Using Floquet theory, we are able to precisely quantify mean-field effects like the alpha and beta effect (i) by rigorously distinguishing dynamo modes that involve large-scale components from the...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 77 21 شماره
صفحات -
تاریخ انتشار 1996