Speaker
Fabio Villone
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P4.1047.pdf
Parametric dependence analysis of disruption forces in tokamaks
F. Villone1, V. Pustovitov2, G. Rubinacci1
1
Consorzio CREATE, DIETI, Università degli Studi di Napoli Federico II, Italy
2
National Research Centre Kurchatov Institute, pl. Kurchatova 1, Moscow 123182, Russia
Disruptions are among the fundamental issues to be tackled in future tokamaks [1]. With rapid
transfer of the magnetic energy, they generate significant (eddy and halo) currents in the
conducting structures. Interaction of these currents with the strong magnetic field present in the
tokamaks is expected to produce substantial electromagnetic forces and torques, which might
challenge even the integrity of the device elements. Consequently, theoretical and experimental
studies on disruption modelling, prediction, avoidance and mitigation are currently in progress.
In this paper, we investigate the dependence of the disruption-induced global electromagnetic
forces on various parameters (resistive wall time, plasma current quench time, vertical
instability growth rate and stability margin). This is a highly debatable area with contradictory
indications and huge scatter of the results [2-5]. The modelling tool that we use is the
CarMa0NL code [6], solving evolutionary axisymmetric equilibrium equations in the plasma,
coupled to 3D volumetric conductors described by the eddy currents equations. This code is
used here to provide predictions for ITER-relevant geometry and range of parameters, since it
has been recently proven adequate to such studies [7]. Indeed, the CarMa0NL results have been
found consistent with the counterintuitive, but theoretically founded property [8] that the total
global electromagnetic force acting on a perfect conductor circumventing the toroidal plasma
must be zero, neglecting plasma inertia. The simulations reproduced this property despite
circulation of significant total current in such ideal wall (up to several MA in ITER) and strong
local electromagnetic force density. Moreover, the results obtained suggested the proposal of
an electromagnetic disruption force damper [7], able to “drain” global force from the
conducting wall. Here we make next steps in analyzing the high-priority disruption issues.
[1] T. Hender et al, Nucl. Fusion 47 (2007) S128
[2] H. Strauss, Phys. Plasmas 25 (2018) 020702
[3] D. V. Mironov and V.D. Pustovitov V.D., Phys. Plasmas 24 (2017) 092508
[4] L. E. Zakharov et al., Phys. Plasmas 19 (2012) 055703
[5] H. Strauss et al., Phys. Plasmas 17 (2010) 082505
[6] F. Villone et al., Plasma Phys. Control. Fusion 55 (2013) 09500
[7] V. D. Pustovitov, G. Rubinacci, F. Villone, Nucl. Fusion 57 (2017) 126038
[8] V.D. Pustovitov, Nucl. Fusion 55 (2015) 1130302
