Speaker
Slavomir Entler
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P1.1017.pdf
ITER steady state magnetic diagnostic
I. Ďuran1, S. Entler1, M. Kočan2, G. Vayakis2, P. Agostinetti3, M. Brombin3, J. M.
Carmona4, G. Gambetta3, N. Marconato3, P. Moreau5, J. Šebek6, M. Kohout6, M. Walsh2
1
Institute of Plasma Physics of the CAS, Prague, Czech Republic
2
ITER Organization, St. Paul Lez Durance Cedex, France
3
Consorzio RFX, Padova, Italy
4
AVS, Elgoibar, Spain
5
CEA, Saint-Paul-Lez-Durance, France
6
Institute of Physics of the CAS, Prague, Czech Republic
Magnetic measurements at long pulse magnetic confinement fusion devices require
implementation of the true steady state magnetic field sensors in order to achieve required
precision of plasma position measurement. Inductive sensors can suffer from a range of
temperature gradient and radiation induced offsets which together with the intrinsic offsets
of analogue integrators can lead to unwanted artificial drifts of their output signals.
Steady state magnetic diagnostic set on ITER is based on sixty Hall effect sensor units welded
onto the outer vacuum vessel skin within three toroidally separated full poloidal arrays. Each
sensor unit contains two Hall sensors with bismuth sensitive layer measuring horizontal and
vertical magnetic field and the thermocouple monitoring Hall sensors temperature.
Temperature monitoring of each sensor unit features the in-situ auto calibration feature
provided by embedded indium capsule. Advanced electronic Hall sensor controller form
essential part of this diagnostic system. It provides high noise immunity employing
synchronous detection and automated offset and planar Hall voltage elimination by periodic
switching of Hall sensor input and output terminals.
Proposed poster presentation will provide overview of present status of development,
qualification, and manufacturing of the steady state magnetic sensors for ITER tokamak. Key
results of the R&D programme spanning over several years and comprising neutron
irradiation testing, measurement of Hall coefficient at high magnetic fields up to 12 T and
high temperatures up to 220 C, long term temperature cycling etc. will be presented. It will
be shown that resulting steady state magnetic diagnostic will comply with ITER requirements
in terms of performance as well as compatibility with operation in ITER environment.
