Speaker
Jeff Candy
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P5.1099.pdf
Integrated core-pedestal modeling with the AToM framework∗
J. Candy1 , E. Belli1 , D. Green3 , C. Holland2 , O. Meneghini1 , J.M. Park3 , S. Smith1 and the AToM team.
1 GeneralAtomics, San Diego, CA
2 Universityof California at San Diego, San Diego, CA
3 Oak Ridge National Laboratory, Oak Ridge, TN
In this presentation we will report on two novel
integrated simulation capabilities of the Ad- CORE TR PED
vanced Tokamak Modeling (AToM) framework.
The original AToM0 SciDAC-3 project was a 3-
year effort that concluded in 2017. For the pe-
riod 2017-2022, a new 5-year AToM SciDAC-4
project has begun. First, we give an overview
of coupled core-pedestal integrated simulations,
with application to DIII-D plasmas. These sim-
ulations take into account the strong interplay
between core turbulent-plus-collisional trans-
port, pedestal structure, current profile and
plasma equilibrium. Integrated modeling work-
flows capable of calculating the steady-state
self-consistent solution to this strongly-coupled
problem have been developed and implemented Experimental data
Successive workflow iterations
in AToM via the OMFIT-TGYRO [1] and the
Pedestal density input to the workflow
IPS-FASTRAN [2] workflows. Here, kinetic
plasma equilibrium is computed by EFIT using
profile data from the transport solver and kinetic
bootstrap current from the neoclassical module.
Given an EFIT equilibrium, core profiles are evolved by the transport solver by combining col-
lisional and turbulent fluxes to maintain balance with heating and fueling sources. The updated
value of the global plasma pressure is passed to EPED to obtain the self-consistent pedestal
structure. For the OMFIT-TGYRO-TGLF-NEO workflow (see plot), the scheme is iterated to
convergence in a few iterations and is independent of initial profiles. By using only the elec-
tron density at the top of the pedestal as an input, profiles are calculated from magnetic axis
to separatrix – in good agreement with experiment (DIII-D 153523, 3745ms). Second, we will
review a key subcomponent of these coupled core-pedestal simulations: the time-dependent
(i.e, mulitple time-slice) kinetic EFIT reconstruction. Here, a self-consistent kinetic neoclas-
sical bootstrap current calculation with NEO is coupled to the EFIT equilibrium solve. This
ensures the highest-accuracy calculation of the bootstrap current and consistent plasma equilib-
rium across the entire plasma profile.
∗ Work supported by US DOE under DE-SC0017992.
References
[1] O. Meneghini, S.P. Smith, P.B. Snyder, G.M. Staebler, J. Candy and E.A. Belli, Nucl. Fusion 57,
0866034 (2017)
[2] J.M. Park, J.R. Ferron, C.T. Holcomb, et al, Phys. Plasmas 25, 012506 (2018)
