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The vector potential and stored energy of thin cosine (n{theta}) helical wiggler magnet [electronic resource].

Published
Washington, D.C. : United States. Dept. of Energy, 1995.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
Physical Description
16 pages : digital, PDF file
Additional Creators
Lawrence Berkeley National Laboratory, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information
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Summary
Expressions for pure multipole field components that are present in helical devices have been derived from a current distribution on the surface of an infinitely thin cylinder of radius R. The strength of such magnetic fields varies purely as a Fourier sinusoidal series of the longitudinal coordinate Z in proportion to cos(nθ- ω{sub m}z), where ω{sub m} = (2m-1)π/L, L denotes the half-period and m = 1, 2, 3 etc. As an alternative to describing such field components as given by the negative gradient of a scalar potential function (Appendix A), one of course can derive these same fields as the curle of a vector potential function {rvec A}--specifically one for which ∇ × ∇ × {rvec A} = 0 and ∇·{rvec A} = 0. It is noted that we seek a divergence-free vector that exhibits continuity in any of its components across the interface r = R, a feature that is free of possible concern when applying Stokes` theorem in connection with this form of vector potential. Alternative simpler forms of vector potential, that individually are divergence-free in their respective regions (r < R and r > R), do not exhibit full continuity on r = R and whose curl evaluations provide in these respective regions the correct components of magnetic field are not considered here. Such alternative forms must differ merely by the gradient of scalar functions that with the divergence-free property are required to be ``harmonic`` (∇²Ψ = 0).
Report Numbers
E 1.99:lbl--38075
lbl--38075
Subject(s)
Other Subject(s)
Note
Published through SciTech Connect.
12/01/1995.
"lbl--38075"
"DE96005012"
Caspi, S.
Funding Information
AC03-76SF00098
View MARC record | catkey: 14353741