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22-27 October 2018
Mahatma Mandir Conference Centre
Asia/Kolkata timezone
CONFERENCE MATERIAL NOW AVAILABLE!

Asymmetric wall force reduction in ITER and JET disruptions

25 Oct 2018, 12:05
20m
Mahatma Mandir Conference Centre

Mahatma Mandir Conference Centre

Gandhinagar (nearest Airport: Ahmedabad), India
Oral THS - Magnetic Confinement Theory and Modelling: Stability EX/6-TH/4 Runways & Disruption Mitigation

Speaker

Dr Henry Strauss (HRS Fusion)

Description

It has been thought that asymmetric vertical displacement event (AVDE) disruptions in
ITER might produce large electromechanical forces on the walls and other conducting structures
surrounding the plasma.
It is shown that ITER
AVDE disruptions
should produce a small
asymmetric wall force, comparable to JET. This is demonstrated in simulations [1,2] with the M3D 3D MHD code [3] and confirmed in JET
experiments [4]
in which the current was quenched with massive gas injection (MGI).
In ITER the current quench (CQ) time, tau_{CQ}, is less than or equal to the resistive wall
penetration time, tau_{wall}.
JET is in a different parameter regime, with tau_{CQ} > tau_{wall}.
JET simulations were validated by comparison [1] to JET shot 71985 data and were in good
agreement. The wall time was then artificially increased, keeping tau_{CQ} fixed,
and it was found
that the wall force decreased.
The reduction of the asymmetric wall force was also found in experimental data [4] of
JET MGI mitigated disruption shots.
Further simulations [2] were carried out of ITER AVDEs. The asymmetric wall force was calculated for a wide range of CQ times.
For tau_{CQ} < tau_{wall}, the force was
not much larger than in JET.
A fast CQ may cause production of runaway electrons (REs).
The effect of replacing part of
of the current with REs on MHD behavior will be discussed.
Simulations using a modified
version of M3D with a fluid RE model [5] will be presented.

Acknowledgment: Work supported by USDOE and
Euratom research and training programme
2014-2018 under grant agreement No 633053,
within the EUROfusion Consortium.
Views and opinions herein do not necessarily reflect
those of the European Commission.

[1] H. Strauss, E. Joffrin, V. Riccardo, J. Breslau, R. Paccagnella, Phys. Plasmas 24, 102512 (2017).

[2] H. Strauss, Physics of Plasmas 25, 020702 (2018).

[3] W. Park, E. Belova, G. Y. Fu, et al., Phys. Plasmas 6, 1796 (1999).

[4] S. Jachmich, P. Drewelow, et al., 43rd EPS Conf. Plasma Physics (2016)

[5] Huishan Cai and Guoyong Fu, Nucl. Fusion 55, 022001 (2015).

Paper Number TH/4-4
Country or International Organization United States of America

Primary author

Dr Henry Strauss (HRS Fusion)

Co-authors

Dr Emmanuel Joffrin (CEA/IRFM) Dr Joshua Breslau (PPPL) Dr Roberto Paccagnella (Consorzio RFX and Istituto Gas Ionizzati del C.N.R.) Dr Stefan Jachmich (EURATOM/UKAEA Fusion Association) Dr Valeria Riccardo (PPPL)

Presentation Materials

Paper