Magnetic field diffusion and dissipation in reversed-field plasmas

1981 ◽  
Vol 24 (1) ◽  
pp. 78 ◽  
Author(s):  
J. F. Drake
Keyword(s):  
Magnetic Field ◽  
Field Diffusion ◽  
Reversed Field

scholarly journals Onset of superconductivity and retention of magnetic fields in cooling neutron stars

2017 ◽  
Vol 13 (S337) ◽  
pp. 213-216
Author(s):  
Wynn C. G. Ho ◽  
Nils Andersson ◽  
Vanessa Graber
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Magnetic Fields ◽  
Neutron Stars ◽  
Minimum Energy ◽  
Meissner Effect ◽  
Energy Conditions ◽  
Field Diffusion ◽  
Neutron Star Cooling ◽  
Proton Pairing

AbstractA superconductor of paired protons is thought to form in the core of neutron stars soon after their birth. Minimum energy conditions suggest that magnetic flux is expelled from the superconducting region due to the Meissner effect, such that the neutron star core retains or is largely devoid of magnetic fields for some nuclear equation of state and proton pairing models. We show via neutron star cooling simulations that the superconducting region expands faster than flux is expected to be expelled because cooling timescales are much shorter than timescales of magnetic field diffusion. Thus magnetic fields remain in the bulk of the neutron star core for at least 106 − 107yr. We estimate the size of flux free regions at 107yr to be ≲ 100m for a magnetic field of 1011G and possibly smaller for stronger field strengths.

Generation of a Reversed-Field Configuration without an Applied Magnetic Field

1978 ◽  
Vol 41 (12) ◽  
pp. 798-801 ◽  
Author(s):  
J. D. Sethian ◽  
K. A. Gerber ◽  
D. N. Spector ◽  
A. E. Robson
Keyword(s):  
Magnetic Field ◽  
Applied Magnetic Field ◽  
Field Configuration ◽  
Reversed Field

scholarly journals Resistive evolution of a force-free plasma to equilibrium

1991 ◽  
Vol 46 (3) ◽  
pp. 437-457
Author(s):  
A. S. Gill ◽  
E. W. Laing
Keyword(s):  
Critical Aspect ◽  
Axial Flux ◽  
Relaxation Theory ◽  
Field Diffusion ◽  
Resistive Plasma ◽  
Maximum Current ◽  
Equilibrium Profiles ◽  
Reversed Field ◽  
Magnetohydrodynamic Model ◽  
Free Plasma

Using the magnetohydrodynamic model, the evolution of a resistive plasma can be represented as a relaxation through a sequence of force-free equilibrium states. We show, by extending existing work, that this process is equivalent to magnetic field diffusion in a strongly anisotropie static conductor. The latter evolution is easier to simulate numerically, and is carried out for laboratory based plasmas confined in cylinders and toroids. We obtain a variety of universal equilibrium profiles that are consistent with experiment and relaxation theory and that predict the existence of states arising in reversed-field pinches. The existence of a critical axial flux is predicted about which there exist stable modes of operation corresponding to high and low current. We also show the existence of a critical aspect ratio at which it is most desirable to build toroidal devices. This corresponds to the value at which maximum current, for a fixed driving field, can be generated.

Sharp-front wave of strong magnetic field diffusion in solid metal

2016 ◽  
Vol 23 (8) ◽  
pp. 082104 ◽  
Author(s):  
Bo Xiao ◽  
Zhuo-wei Gu ◽  
Ming-xian Kan ◽  
Gang-hua Wang ◽  
Jian-heng Zhao
Keyword(s):  
Magnetic Field ◽  
Strong Magnetic Field ◽  
Solid Metal ◽  
Field Diffusion ◽  
Sharp Front
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