Design & Test of a Split Florida-Helix Model
In recent years the NHMFL has started to develop high-
field powered magnets with configurations other than
simple solenoids. Specifically, a preliminary design of a
resistive magnet with a mid-plane split for use in far-
infrared photon scattering experiments was completed
at the conceptual level. This user magnet, to be
operated at our own facility, should provide a flux-
density in the range of 25-30 T depending on the final
gap dimensions using less than 28 MW of dc power.
The magnet will include four large scattering ports of
elliptical shape at the mid-plane. Such a magnet
configuration results in unique design challenges being
especially severe for the windings in the mid-plane
region of the innermost coils. Consequently, the NHMFL
developed a new technology called split Florida-helix. To
test and demonstrate those new concepts, the NHMFL
recently completed the design, fabrication, and test of a
working model of a split Florida-Helix. The working
model was tested successfully (in the existing Large
Bore Magnet) up to 18 kA and a center field above 32 T
(incl. 19.5 T background field).
M.D. Bird, Presented at 20th International Conference on Magnet Technology, Philadelphia, Aug 2007 (Core funded)
FEA-Aided Design of a Split Florida-Helix Model
Advanced 3-D finite element models have been
developed at the NHMFL aiding the design
optimization of a Split Florida Helix Model.
The first model allowed a thermal-electric analysis
(in ANSYS) including the evaluation of the current
distribution over the four ports at the midplane.
A second model (derived from the thermal-electric
model) including turn-to-turn stick-slip contact
surfaces was used for a non-linear structural
analysis (in ANSYS) evaluating the structural
performance and stability of the Magnet System.
The complex and sophisticated FEA performed
proved to be essential for the development of the
new split Florida-Helix technology.
J. Toth & M.D. Bird, Presented at 20th International Conference on Magnet Technology, Philadelphia, Aug 2007
CED for 30T Neutron Scattering Magnet
SNS Scattering magnet
35 We are developing the
30 KEK technology for a new type
25 of magnet suitable for
NHMFL experiments at 30T with a
scattering angle of 30
NIST degrees. This magnet will
provide a combination of
0 field and solid angle
0 10 20 30 40
worldwide as shown to the
A critical part of this is development of the technology
suitable for the resistive insert. A coil has been designed as
shown to the right. Fabrication is underway.
M.D. Bird et al., Presented at 20th International Conference on Magnet Technology, Philadelphia, Aug 2007 (SNS grant)