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@ARTICLE{Christmann:639234,
author = {Christmann, Jan-Magnus and D'Angelo, Laura Anna Maria and
De Gersem, Herbert and Pfeiffer, Sven and Mirza, Sajjad
Hussain and Thede, Matthias and Aloev, Alexander and
Schlarb, Holger},
title = {{H}omogenized harmonic balance finite element method for
nonlinear eddy current simulations of fast corrector
magnets},
reportid = {PUBDB-2025-04354, arXiv:2503.19657},
year = {2025},
note = {18 pages, 27 figures, to be published in Physical Review
Accelerators and Beams},
abstract = {This paper develops a homogenized harmonic balance finite
element method (HomHBFEM) to predict the dynamic behavior of
magnets with fast excitation cycles, including eddy current
and skin effects. A homogenization technique for laminated
yokes avoids resolving the individual laminates and the skin
depth in the finite element (FE) mesh. Instead, the yoke is
represented by a bulk surrogate material with
frequency-dependent parameters. The ferromagnetic saturation
of the yoke at higher excitation currents is tackled by a
harmonic balance method, which accounts for a coupled set of
frequency components. Thereby, a computationally expensive
time stepping of the eddy-current field problem and a
convolution of the homogenized yoke model are avoided. The
HomHBFEM enables, for the first time, nonlinear simulations
of fast corrector magnets, which are embedded in a fast
orbit feedback system to counteract orbit disturbances over
a broad frequency spectrum, and thus guarantee stable
light-source operation. The results show the impact of the
nonlinearity on the phase lag and the field attenuation, as
well as the eddy current losses at frequencies up to several
tens of kilohertz. The numerical validation for a C-dipole
magnet example shows that the HomHBFEM achieves a sufficient
accuracy at an affordable computational effort, with
simulation times of a few hours. In comparison, standard 3D
transient FE simulations need to resolve the lamination
thickness and the skin depth in space and the largest
relevant frequency in time, which leads to a 2 to 3 orders
of magnitude larger mesh and prohibitive computational
effort, with simulation times of a few weeks on a
contemporary computer server.},
cin = {MSK / MEA1},
ddc = {530},
cid = {I:(DE-H253)MSK-20120731 / I:(DE-H253)MEA1-20210408},
pnm = {621 - Accelerator Research and Development (POF4-621) / GRK
2128 - GRK 2128: AccelencE: Beschleunigerphysik und
–technologie für Teilchenbeschleuniger mit
Energierückgewinnung (264883531)},
pid = {G:(DE-HGF)POF4-621 / G:(GEPRIS)264883531},
experiment = {EXP:(DE-H253)PETRAIV-20220101},
typ = {PUB:(DE-HGF)25},
eprint = {2503.19657},
howpublished = {arXiv:2503.19657},
archivePrefix = {arXiv},
SLACcitation = {$\%\%CITATION$ = $arXiv:2503.19657;\%\%$},
url = {https://bib-pubdb1.desy.de/record/639234},
}