skip to main content

DOE PAGESDOE PAGES

This content will become publicly available on October 20, 2016

Title: Generation of large-scale magnetic fields by small-scale dynamo in shear flows

We propose a new mechanism for a turbulent mean-field dynamo in which the magnetic fluctuations resulting from a small-scale dynamo drive the generation of large-scale magnetic fields. This is in stark contrast to the common idea that small-scale magnetic fields should be harmful to large-scale dynamo action. These dynamos occur in the presence of a large-scale velocity shear and do not require net helicity, resulting from off-diagonal components of the turbulent resistivity tensor as the magnetic analogue of the "shear-current" effect. Furthermore, given the inevitable existence of nonhelical small-scale magnetic fields in turbulent plasmas, as well as the generic nature of velocity shear, the suggested mechanism may help explain the generation of large-scale magnetic fields across a wide range of astrophysical objects.
Authors:
 [1] ;  [2]
  1. Princeton Univ., NJ (United States). Dept. of Astrophysical Sciences; Max Planck & Princeton Ctr Plasma Phys, Princeton, NJ 08543 USA; Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); California Inst. of Technology (CalTech), Pasadena, CA (United States)
  2. Princeton Univ., NJ (United States). Dept. of Astrophysical Sciences; Max Planck & Princeton Ctr Plasma Phys, Princeton, NJ 08543 USA; Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Publication Date:
OSTI Identifier:
1259593
Report Number(s):
PPPL--5148
Journal ID: ISSN 0031-9007; PRLTAO
Grant/Contract Number:
AC02-09CH11466
Type:
Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 115; Journal Issue: 17; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Research Org:
Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY