Formation of the non-axisymmetric helical current driven by a biased electrode in the scrape-off layer on J-TEXT

The instrument described is the outcome of conversations between the late Professor J. Viriamu Jones, F. R. S., and one of the authors (W. E. A.), on their return from the British Association Meeting held in Toronto in 1897. Its object was to determine “ the ampere ” as defined in the C. G. S. system, to an accuracy comparable with that attained in the absolute determination of the ohm by Lorenz’s apparatus, an account of which was given by Professors Ayrton and Jones at the Toronto Meeting. Professor Jones had previously developed a convenient formula for calculating the electromagnetic force between a helical current and a coaxial current sheet, viz., F = γ h γ (M 2 -M 1 ),† where γ h is the current in the helix, the γ current per unit length of the current sheet, and M 1 , M 2 the coefficients of mutual induction of the helix and the two ends of the current sheet respectively. By using coaxial coils with single layers of wire wound in screw-thread grooves, advantage could be taken of the above formula.

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Modelling of LHW-induced helical current filaments on EAST: study of an alternative method of applying RMPs

Nuclear Fusion ◽

10.1088/0029-5515/54/6/064016 ◽

2014 ◽

Vol 54 (6) ◽

pp. 064016 ◽

Cited By ~ 4

Author(s):

M. Rack ◽

L. Zeng ◽

P. Denner ◽

Y. Liang ◽

A. Wingen ◽

...

Keyword(s):

Alternative Method ◽

Current Filaments ◽

Helical Current

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On the calculation of the coefficient of mutual induction a circle and a coaxial helix, and of the electromagnet force between a helical current and a uniform coaxial circular cylindrical current sheet

Proceedings of the Royal Society of London ◽

10.1098/rspl.1898.0023 ◽

1898 ◽

Vol 63 (389-400) ◽

pp. 192-205 ◽

Cited By ~ 7

Keyword(s):

General Solution ◽

Current Sheet ◽

Electrical Resistance ◽

Circular Disc ◽

Mcgill University ◽

The Mean ◽

Helical Current ◽

Mutual Induction

1. In measuring electrical resistance by the method of Lorenz have to determine the coefficient of mutual induction of a helix wire and the circumference of a rotating circular disc placed coaxially with it, the mean planes of the helix and the disc being coincident. In a paper presented to the Physical Society November, 1888, I gave a method of calculating this coefficient; by subsequent consideration of the problem in connection with the Lorenz apparatus recently made for the McGill University, Montrea has led me both to a simplification of the method previously described, and also to a more general solution. 2. If M is the coefficient of mutual induction of any two curve we have M = ∫∫cos ϵ / r dsds' , where r = the distance between two elements ds, ds' ; and ϵ = the angle between these elements.

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