ITER VDE modeling for disruption mitigation design
POSTER
Abstract
ITER has a vacuum vessel (VV) of a wall time $sim 500$~ms, while the
desired current quench time $ au_{CQ}$ is around 100~ms, so there is
little room for active feedback control from coils outside the VV, in
contrast to current tokamaks. The first wall and blanket modules are
constructed and arranged on ITER to impede net toroidal current, so
they would not obstruct the poloidal magnetic flux from penetrating
through. A current-carrying plasma column can thus scrape off against
the first wall while the effect of a good flux conserver is felt at a
standoff distance away. This two-layer setup also channels the halo
current in ways that are different from current tokamak experiments.
The consequence is that both the VDE dynamics and its mitigation would
require special consideration to simulate on current tokamak
experiments, the subtlety of which can be clarified by modeling. Here
we report a comprehensive suite of simulation codes that track both
the axisymmetric and 3D VDE dynamics, and the physics findings on how
a VDE can be effectively mitigated on ITER. $^*$Work supported under
TDS SciDAC project.
desired current quench time $ au_{CQ}$ is around 100~ms, so there is
little room for active feedback control from coils outside the VV, in
contrast to current tokamaks. The first wall and blanket modules are
constructed and arranged on ITER to impede net toroidal current, so
they would not obstruct the poloidal magnetic flux from penetrating
through. A current-carrying plasma column can thus scrape off against
the first wall while the effect of a good flux conserver is felt at a
standoff distance away. This two-layer setup also channels the halo
current in ways that are different from current tokamak experiments.
The consequence is that both the VDE dynamics and its mitigation would
require special consideration to simulate on current tokamak
experiments, the subtlety of which can be clarified by modeling. Here
we report a comprehensive suite of simulation codes that track both
the axisymmetric and 3D VDE dynamics, and the physics findings on how
a VDE can be effectively mitigated on ITER. $^*$Work supported under
TDS SciDAC project.
*This work was supported by DOE OFES and OASCR through the SciDAC program
Presenters
-
Xianzhu Tang
- Los Alamos Natl Lab