Fusion Engineering and Design 48 (2000) 127 – 134
ASDEX Upgrade MHD equilibria reconstruction on
distributed workstations
W. Schneider
a,
*, P.J. McCarthy
b
, K. Lackner
a
, O. Gruber
a
, K. Behler
a
,
P. Martin
a
, R. Merkel
a
a
Max -Planck -Institut fu ¨r Plasmaphysik, EURATOM Association, Boltzmannstr. 2, 85748 Garching bei Mu ¨nchen, Germany
b
Department of Physics, Uniersity College Cork, Association EURATOM-DCU, Cork, Ireland
Received 30 July 1999; received in revised form 8 December 1999; accepted 29 March 2000
Abstract
The identification of MHD equilibrium states on the ASDEX Upgrade tokamak is a prerequisite for interpreting
measurements from a wide range of diagnostics which are correlated with the shape of the plasma. The availability
in realtime of plasma parameters related to the MHD state is crucial for controlling the experiment. Function
Parameterization is used as a standard tool to determine the position, shape, and other global parameters of the
plasma as well as the MHD equilibrium flux surfaces. The recently developed interpretive equilibrium code CLISTE
now enables the calculation of MHD equilibria on an intershot timescale. These calculations are parallelized by the
use of a Message Passing Interface (MPI). © 2000 Elsevier Science S.A. All rights reserved.
Keywords: ASDEX; MHD; Message passing interface (MPI)
www.elsevier.com/locate/fusengdes
1. Introduction
The basis of all tools developed to identify the
MHD equilibrium state on the ASDEX Upgrade
tokamak experiment is the Garching Equilibrium
(GEC) code package [1]. The GEC finds a numer-
ical solution to the Grad – Shafranov equation of
MHD equilibrium in a tokamak [2,3].
-
2
R
2
-
1
R
R
+
2
Z
2
=
o
R
2
p ( ) +FF ( )
o
Rj
(1)
for a given set of poloidal field coil currents and
limiter structures and a specified parameterization
of the p ( ) and FF ( ) source profiles which
define the toroidal current density profile j
.
The GEC package is used, for example, to
carry out conceptual studies for a new divertor
for ASDEX Upgrade, currently being designed
for operation in 2001. The results of this type of
calculation can be stored as ASDEX Upgrade
shotfiles {EQA} (see Fig. 2).
Paper presented at the IAEA Technical Committee Meet-
ing on Control, Data Acquisition and Remote Participation
on Fusion Research, Lisboa, 1999 July 19–21.
* Corresponding author. Tel.: +49-89-32991222; fax: +49-
89-32991222.
E-mail address: wolfgang.schneider@ipp.mpg.de (W.
Schneider).
0920-3796/00/$ - see front matter © 2000 Elsevier Science S.A. All rights reserved.
PII:S0920-3796(00)00109-5