Abstracts Brochure - CERN

WEPLS094
WEPLS096
WEPLS097
28-Jun-06 16:00 - 18:00 WEPLS — Poster Session
3D Transient Magnetic Field and Eddy Current Loss Calculations for Iron Dominated Accelerator
Magnets Using ANSYS Compared with the Results of Noncommercial Codes
P.A. Shcherbakov (IHEP Protvino) E. Fischer, G. Moritz (GSI) R.V.
Kurnyshov (Electroplant)
360
The design of fast ramped superferric magnets
with repetition rates in the order of 1Hz
requires reliable software tools to calculate
the complex 3D magnetic field quality as well
as the impact of eddy current and hysteresis loss. Various technological construction details should be taken into
account to obtain a high field quality. We present a methodical study of these questions based on ANSYS calculations
for simplified dipole models. The details of these analysis are compared with recently published results obtained by
different special codes, i.e. an integral and the FIT method. The time dependences of eddy current power due to longitudinal
magnetic field component at the yoke ends, the transient field distribution in the yoke volume and the total
eddy current loss are investigated, choosing the identical geometry with the same magnetic and electric properties of
the lamination steel used by the other codes. The conclusions for the application potential of the different methods
are discussed.
Design and Calculation of a Superferric Combined Magnet for XFEL
F. Toral, P. Abramian, J.L. Gutierrez, E. Rodriguez, I. Rodriguez, S.
Sanz, C. Vazquez (CIEMAT) R. Bandelmann, H. Brueck (DESY) J.
Calero, L. García-Tabarés (CEDEX) J. Lucas (Elytt Energy)
A new free electron X-ray laser so-called
XFEL is being developed within the framework
of an international collaboration. The
design and fabrication of a prototype of a
combined magnet is part of the Spanish con-
tribution to this project. This magnet consists of a superferric quadrupole coil for focusing and two nested dipoles
(horizontal and vertical) for steering, glued around the beam tube. The magnet will be operated in a superfluid
helium bath. The aperture is 78 mm. The quadrupole gradient is 35 T/m while each dipole field is about 0.04 T.
Each of the about 120 acceleration modules contains one magnet package. The current in the focusing quadrupole
increases along the Linac with increasing beam energy. The magnetic saturation is limited to 5% at nominal current,
which is quite a challenging specification for such aperture and gradient. As the overall length is just 300 mm, the
calculation of the magnetic field is a pure 3-D problem which has been solved and optimized using two different FEM
codes to cross-check the results. This paper also gives some guidelines about the fabrication techniques most suitable
for the first prototype, which is now under construction.
Study of Geometrical Random Errors in Magnetic Field of Accelerator Magnets
The magnetic field in a superconducting
B. Bellesia, E. Todesco (CERN)
magnet is mainly determined by the positioning
of the conductors. Hence, the main
contribution to the random field errors comes from random displacement of the coil with respect to the nominal
position. An analytical method and scaling laws to estimate the random magnetic field errors in different dipole
configurations (from the simplest configuration of four wires to a more realistic block lay-out) are presented here.
The dependence of the random errors on the aperture and coil width, on the precision of the coil layout and on the
azimuthal position is discussed. We also focus on the origin of asymmetries between the random part of normal and
skew components of the same order, which has been observed in measurements of magnet productions of several