TY - JOUR
T1 - Plasma Edge Kinetic-MHD Modeling in Tokamaks Using Kepler Workflow for Code Coupling, Data Management and Visualization
AU - J. Cummings, A. Pankin, N. Podhorszki, G. Park, S. Ku, R. Barreto, S. Klasky, C. S. Chang, H. Strauss, L. Sugiyama, P. Snyder, D. Pearlstein, B. Ludäscher, G. Bateman, A. Kritz & the CPES Team
JO - Communications in Computational Physics
VL - 3
SP - 675
EP - 702
PY - 2008
DA - 2008/09
SN - 4
DO - http://doi.org/
UR - https://global-sci.org/intro/article_detail/cicp/7811.html
KW - 
AB - <p style="text-align: justify;">A new predictive computer simulation tool targeting the development of
the H-mode pedestal at the plasma edge in tokamaks and the triggering and dynamics
of edge localized modes (ELMs) is presented in this report. This tool brings together, in
a coordinated and effective manner, several first-principles physics simulation codes,
stability analysis packages, and data processing and visualization tools. A Kepler
workflow is used in order to carry out an edge plasma simulation that loosely couples
the kinetic code, XGC0, with an ideal MHD linear stability analysis code, ELITE, and
an extended MHD initial value code such as M3D or NIMROD. XGC0 includes the
neoclassical ion-electron-neutral dynamics needed to simulate pedestal growth near
the separatrix. The Kepler workflow processes the XGC0 simulation results into simple images that can be selected and displayed via the Dashboard, a monitoring tool
implemented in AJAX allowing the scientist to track computational resources, examine running and archived jobs, and view key physics data, all within a standard Web browser. The XGC0 simulation is monitored for the conditions needed to trigger an
ELM crash by periodically assessing the edge plasma pressure and current density
profiles using the ELITE code. If an ELM crash is triggered, the Kepler workflow
launches the M3D code on a moderate-size Opteron cluster to simulate the nonlinear ELM crash and to compute the relaxation of plasma profiles after the crash. This
process is monitored through periodic outputs of plasma fluid quantities that are automatically visualized with AVS/Express and may be displayed on the Dashboard.
Finally, the Kepler workflow archives all data outputs and processed images using
HPSS, as well as provenance information about the software and hardware used to
create the simulation. The complete process of preparing, executing and monitoring
a coupled-code simulation of the edge pressure pedestal buildup and the ELM cycle
using the Kepler scientific workflow system is described in this paper.</p>