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waveforms, and two different heaters were used to heat the
jacket or the helium. The sample was equipped with many
thermal-hydraulic (thermometers and mass-flow meters)
and electrical (Hall probes and voltage taps) sensors, to
acquire as wide as possible an experimental database,
aimed at getting a benchmark for the validation of the
THELMA code. THELMA is a computer tool for the analysis
of CICC prototypes and magnets, recently developed and
presently under validation. Starting from the object
geometry, its CICC data and the waveforms of forced
current and external heating power, THELMA can compute
the current distribution among the cable elements used to
represent the cable, taking into account their
superconducting behaviour, as well as the temperature and
the magnetic field distribution. The paper deals with the
application of THELMA to some representative tests on
BBIII and presents in detail the analysis setting-up, the
results, its critical aspects and limits. A comparison is
shown between the measured and the computed
waveforms of the electromagnetic and the thermalhydraulic
data.
MOA05PO03
The effect of geometry and location of suspension
coils on magnetic levitation force for an
electromagnetic suspension of a superconducting
sphere
C. He, Q. Wang, Institute of Electrical Engineering, CAS.
In this paper, we present the calculation of magnetic
levitation force of superconducting sphere suspended by
coils. The influence on magnetic levitation force due to
geometrical dimensions and relative locations of coils is
analyzed. Theoretical computational results have been
discussed by comparison with numerical simulation results.
By the work it is a possible approach to achieve a stable
suspension of superconducting sphere.
MOA05PO04
Modeling of Magnetic Force Control Device Based on
the Inverse Magnetostrictive Effect
S. Cao, B. Wang, J. Zheng, W. Huang, Y. Sun, L. Weng,
Hebei University of Technology.
A device using the inverse magnetostrictive effect of
magnetostrictive materials (such as Terfenol-D) is called a
magnetostrictve sensor. Magnetostrictve sensors have
high energy coupling factors and fast response. Thus, the
sensors have a wide range of applications in hydrophones,
torque sensor, displacement and force sensor, etc. The
difficulty for the sensors, however, lies in the hysteretic
nonlinearity inherent to Terfenol-D. To design and use the
sensors, it is necessary to establish an accurate model of
Terfenol-D. The linear piezomagnetic equations (Clark,
1980) and related modeling techniques (Fenn & Gerver,
1994; Kleinke & Uras, 1996) provide adequate
characterization of Terfenol-D sensing performance in
quasi-linear regimes, hysteresis models for characterizing
Terfenol-D sensing performance are still lacking. To
address this problem, this paper first presents a hysteresis
model of Terfenol-D, and then uses the model to found a
magnetic force model for a magnetic force device (Ueno,
Qiu and Tani, 2004). In the modeling of Terfenol-D, the
magnetization of Terfenol-D is quantified under a magnetic
field and a stress field. The field-induced component of
magnetization is quantified with the ferromagnetic
hysteresis model (Jiles & Atherton, 1986). The stressinduced
component of magnetization is modeled with the
law of approach (Jiles,1995). It is found that the model
results are in a good agreement with the experimental
data.
MOA05PO05
Property of Mechanical Heat Generation inside the
Superconductiing Coil installed in MAGLEV Inner
Vessel
Y. Yoshino, Hachinohe National College of Technology; A.
Iwabuchi, T. Suzuki, Iwate University; H. Seino, Railway
Technical Research Institute.
n the JR MAGLEV system, trains are operated by the
electromagnetic force between ground coils and on-board
superconducting magnets (SCMs). However, SCMs are
vibrated by the electromagnetic disturbance during the train
runs. This phenomenon increases the mechanical heat
load inside the inner vessel installed with a
superconducting coil (SC- coil). One of the mechanical
heat load is generated by the friction caused by the relative
microscopic slips between fasteners and the SC-coil. The
purpose of this study is to clear the mechanical heat
generation inside the SC-coil. A frictional test was
performed under fretting conditions against immersing SCcoil
samples in liquid helium. Especially, we focused on the
interface of the polyimide films which coated epoxy resinimpregnated
SC-winding wires. Reciprocating slidings were
provided between the fixed and vibrating specimens with
the maximum peak-to-peak amplitude less than 30 microns
by a vibration generator. Specimens were vibrated up to
the frequency of 300 Hz. As a result, the mechanical heat
generation increased with increasing of the number of
polyimide films.
MOA05PO06
Rotation Loss Modeling in Superconducting Magnet
Bearing
I. Masaie, K. Demachi, M. Uesaka, The University of
Tokyo.
In superconducting magnet bearings there are 3 major
physics problems, AC Loss, non-linear motion and irregular
trap field of the superconductor. The effect of AC Loss and
non-linear motion is reduced through the manufacturing
techniques and the control systems. However the angular
velocity loss increases as the rotation velocity increases or
the irregular trap field is enhanced. We have considered
that the angular velocity loss come of the Lorentz force
between the irregular trap field of the superconductor and
the current induced by the irregular field. Thus far the loss
has been evaluated in our computer simulation method. In
this study, we devised the rotation loss modeling in terms
of the motion equation, and the model is demonstrated by
the computer simulation and our experiment.
MOA05PO07
The study on the electromagnetic characteristics of the
pilot-plant-scale linear electromagnetic stirrer using
finite element method
M-K. Song, Vector Fields Korea. Inc.; S-J. Lee, E.E. Dept.
Uiduk University; J-P. Park, Research Institute of Industrial
Science & Technology.
Withdrawn.
MOA05PO08
The study on the electromagnetic characteristics of
square type EMC molds using finite element method
M-K. Song, Vector Fields Korea. Inc.; S-J. Lee, E.E. Dept.
Uiduk University; B-M. Moon, J-S. Shin, KERI.
Withdrawn.
MOA05PO09
Computational Simulation of the interaction between
PM and HTS bulk
M. Qiu, G.H. Yang, L.Z. Lin, Institute of Electrical
MT-19 2005, Genova 32