Speaker
Louis Giannone
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P2.1041.pdf
Real-time equilibrium reconstruction integration
into the ASDEX Upgrade control system
L.Giannone, B.Sieglin, R.Fischer, J.C.Fuchs, P.J.McCarthy1 , K.H.Schuhbeck
and the ASDEX Upgrade Team
Max Planck Institute for Plasma Physics, EURATOM Association, 85748 Garching, Germany
1 Department of Physics, University College Cork, Association EURATOM-DCU, Cork, Ireland
The real-time equilibrium reconstruction code for the ASDEX Upgrade tokamak, JANET
[1], is in the process of migration to a Linux based C11++ code. This is motivated by the need
for closer integration into the control system and the long term goal of replacing the currently
used function parameterisation based control when upper divertor coils for studying advanced
magnetic configurations are installed [2].
The benchmarks of the individual elements are presently being optimised. The parameters for
the position and orientation of the magnetic probes and flux loops, the position of the poloidal
field coils and limiters and the surface locations of the 7 rows of ferromagnetic tiles installed
in 2017 are input from an XML based machine description file. The setting up of the 12 basis
current functions on the flux matrix from the previous time step requires 105 µs. On a 65x129
grid, the Grad-Shafranov solver then calculates a solution in 130 µs that is a best fit to the
magnetic probe measurements. Contour integrals at 10 normalised radii required for input to
the RAPTOR code [3] and at the separatrix to calculate beta poloidal and plasma inductance
are carried out in 100 µs.
Integrators for magnetic probe arrays at 4 additional toroidal locations have been developed.
The 16 bit ADC’s of the integrators can acquire data with a sample frequency up to 100 kHz and
with a software selectable integration time. There are 16 channels in a crate with an interface
card and four crates are connected to a PXIe 7821 FPGA. The recorded data is transmitted in
real-time by an optical bus extender (MXI Express x4) to the computing node with an 8 core
Intel Xeon E5-2667 v3 running at 3.2 GHz.
References
[1] L. Giannone, R. Fischer, P. McCarthy, et al., Improvements for real-time magnetic equilib-
rium reconstruction on ASDEX Upgrade, Fusion Eng. Des. 100 (2015) 519.
[2] T. Lunt, H. Zohm, A. Herrmann, et al., Proposal of an alternative upper divertor in ASDEX
Upgrade supported by EMC3-EIRENE simulations, Nucl. Mat. and Energy 12 (2017) 1037.
[3] F. Felici, O. Sauter, S. Coda, et al., Real-time physics-model-based simulation of the current
density profile in tokamak plasmas, Nucl. Fusion 51 (2010) 083052.
