Extension of DIII-D Scenarios and Control to Long
Pulse in EAST
D. Humphreys, A. Garofalo (General
Atomics), B. Xiao, B. Wan (ASIPP), P.
Bonoli (MIT), E. Doyle (UCLA), K.
Gentle (U. Texas), C. Holcomb (LLNL),
J-M. Park (ORNL), E. Schuster (Lehigh
U.), W. Solomon (PPPL)
US-China Workshop 2012
Univ. of California – San Diego
9-11 July 2012
EAST
DIII-D
Overview
• EAST/DIII-D Control Collaborations 2004-2012
• US International Collaboration Solicitation April 2012
• Proposed collaboration on Scenarios and Control 2013-15
• Collaboration strategy and approaches
• Conclusions
EAST/DIII-D Control Collaboration 2004-06 Focused on
Plasma Control System and Operational Support
• Development/deployment of EAST Plasma
Control System (PCS) 2004-06:
– Adapted from DIII-D PCS, specialized
fault response algorithms
– Joint project between DIII-D and EAST
control teams
– Commissioned prior to EAST first plasma
campaign 2006
• EAST First Plasma campaign 2006:
– Collaboration designed
breakdown/startup scenarios
– Circular/low elongation limited plasma
control algorithms
– Fundamental control response
characterization and physics modeling
Good
Null
EAST/DIII-D Control Collaboration 2007-12 Focused on
Equilibrium Control and Experimental Research
• Steady advances in shaped plasma long pulse
control 2007-2012:
– Realtime EFIT equilibrium reconstruction
– Isoflux boundary/divertor control algorithm
– Double null shape control (can be unbalanced
single null)
– Upper/lower single null shape control
– Strikepoint control
– Long pulse realtime data archiving
• Controllability research and ITER target
development 2012:
– Plasma response characterization/modeling
– Vertical controllability experiments/calculation
– Development of ITER target adapted to EAST
geometry and RF heating systems
– Initial studies with ITER baseline scenario:
Development of ITER target H-mode, study of
effect of B direction on threshold power

Inner
Inner
strike
strike
point
point
control
contro
l
US DOE Solicitation April 2012 Invited Proposals for
3-Year Collaboration with EAST (2013-2015)
• Motivation:
– ASIPP/EAST have long and generously welcomed US collaboration in many areas
– Recent DOE studies (ReNeW 2009, FESAC 2012) have identified many “gap” areas not filled by
US experimental research facilities and programs
– EAST offers (among many other features):
– Long pulse capability (pulse length > many resistive times at high performance AND > wall
thermal/particle equilibration time)
– High heating/current drive power expected in short term (> 25 MW by end 2015) with
mixed sources including ICRF, LHCD, NBI, ECH
– Metal wall/divertor with expectation of active hot wall operation
– Planned in-vessel nonaxisymmetric coils with broad mode spectrum
– Strong scenario/control emphasis with history of strong support for control research and
fully noninductive scenarios
• Solicitation Elements:
–
–
–
–
–
Transport: understanding in high performance, extrapolation to next step devices
Long pulse control: maintaining high performance at operating points near stability limits
Plasma-wall interaction: erosion, survivability, particle and thermal equilibrium
Divertor optimization: magnetic configuration for heat flux spreading
Auxiliary systems: heating/current drive for long pulse control and sustained high performance
GA Has Led a Proposal for US-EAST Collaboration on
Scenarios and Control Research
• Elements of Proposed Project:
– Adapt scenarios for ITER and advanced steady state from Alcator C-Mod and
DIII-D for implementation and study on EAST
– Develop control solutions for long pulse execution of scenarios
– Control research toward robust disruption-free operation
– Novel use of heating and current drive systems for long pulse regulation of
scenarios
– Extensive use of simulations to adapt, optimize, and understand scenarios
– Extensive use of remote collaboration tools for maximum effectiveness of US
collaborators
– Significant on-site visits by US researchers to ASIPP, and ASIPP researchers to US
facilities
• US Collaborating Team includes 8 US Institutions and ASIPP:
– General Atomics (lead institution), Massachusetts Institute of Technology, Princeton
Plasma Physics Laboratory, Lawrence Livermore National Laboratory, Oak Ridge
National Laboratory, Lehigh University, Univ. of California (Los Angeles), Univ. of
Texas (Austin)
– Extensive history of collaboration with EAST
– Focused expertise in scenarios, control, diagnostics, actuators, simulations
Task 1 Will Adapt ITER and Advanced Scenarios from DIII-D
and Alcator C-Mod for Execution and Research on EAST
• Extending/optimizing ITER Inductive and
Advanced Steady State Scenarios
scenarios for Long Pulse:
– Adapt actuator use from US machines
to EAST
– Develop long pulse discharge
scenario trajectories
– Adapt and develop targets and
control algorithms required
– Study scenarios with metal walls on
wall-equilibration timescale
• ITER scenarios will be studied on both
EAST and KSTAR
• Study of advanced scenarios will focus on
EAST owing to expected availability of
high heating power by 2014
DIII-D ITER Scenario
Task 1 Will Adapt ITER and Advanced Scenarios from DIII-D
and Alcator C-Mod for Execution and Research on EAST
• ITER scenarios in EAST enable study of
many issues and challenges:
– Operation close to vertical control
and tearing stability limits
– Tight margins for superconducting
and resistive coils
– Behavior of scenarios with metal walls
in very long pulse
• Steady state scenarios in EAST
complement physics studies in US:
– Existence of stationary high rho-qmin
scenarios: Profile sustainment over
many resistive times in high
performance
– Graphite/cold walls: Effect of hot
metal walls in long pulse
– Robust control algorithms for
disruption-free operation: Extension
and optimization for long pulse
disruption-free sustained operation
DIII-D ITER Scenario
Vertical
instability
Tearing
instability
Vertical
instability
Task 2 Will Develop Control Solutions Needed for Scenario
Execution on EAST and Perform Control Research
• Control task includes 4 key elements:
– Nominal scenario control algorithms
– Model-based algorithms for robust
disruption free control
– Off-normal response algorithms
– Disruption characterization/mitigation
• Synergistic control research between EAST
and DIII-D:
– Develop robust control solutions on DIII-D
– Adapt and transfer algorithms to EAST
– Determine superconducting/RF/long
pulse/wall issues
– Validate models on EAST
– Model-based design for EAST (and DIII-D)
– Focused experiments on DIII-D to
emulate control environment (EAST, ITER)
– Common use of DIII-D PCS enables
efficient sharing of control schemes and
algorithms
Task 3 Will Support Development of Diagnostics and
Actuator Use on EAST
• Support development of key diagnostics:
– Needed for advanced steady state
profile control
– ITER-relevant
– Polarimetry
– Profile reflectrometry
– Charge Exchange Recombination
Spectrometer (Ti, Vtor, Vpol)
– X-ray Imaging Crystal Spectrometer (Ti,
Vtor)
• Support development of methods for use of RF
actuators:
– Analysis and experiment to optimize
effectiveness of LHCD, ICRF and develop
methods for application to scenarios
– Validation of actuator models
– Novel use of RF for rotation and current
profile control
EAST profile
reflectometer
development will be
supported (DIII-D
data shown)
LHRF-driven fast
electron fraction
drops, LHCD
efficiency rises as ne
(and Te) increase
(C-Mod data shown)
Task 4 Will Execute and Validate Simulations to Support
Scenario/Control Development and Understanding
• Simulation task includes 4 elements:
– Development and validation of
simulations for scenario extension to
EAST
– Control-level model implementation
in 1.5D codes
– Execute simulations for scenario
design
– Execute simulations for control design
• Simulations will make use of many
codes:
– 1.5D axisymmetric free boundary,
resistive plasma flux evolution,
transport (TSC, Corsica)
– Transport simulation with high fidelity
source models (TRANSP, CURRAY,
GENRAY, NUBEAM, TORIC, LSC,
TORAY…)
TSC Simulation of C-Mod ITER Scenario
Reproduces Key Physics Behavior
Task 5 Will Provide and Support Tools Needed for Remote
Collaboration and Third Shift Operation of EAST
• Extensive reliance on remote collaboration and
experimental participation will require many
tools to be supported:
– Remote data access and display codes
– Hardware and network infrastructure for fast
data transfer and archiving at remote sites
– Remote control room for physics operations
and experimental participation
– Secure remote programming of EAST PCS
• Third shift operation of EAST from GA Remote
Control Room maximizes use of China nighttime operation:
– US scientists operate EAST and lead EAST
experiments during US daytime
– Physics (PCS) operation from GA
– Remote engineering and machine
operations liason officers
General Atomics Remote
Control Room
Integrated and Coordinated Approach to
Collaborative Project Maximizes Effectiveness
• All task elements support and contribute to
scenarios/control:
– DIII-D/C-Mod scenarios characterized and
adapted for EAST (Task 1)
– New diagnostics, actuator use developed for
EAST, applied to scenarios (Task 3)
– Control algorithms achieve scenarios and
develop robust solutions for future (Task 2)
– Simulations develop and verify scenario
approaches, verify control function, enable
extension to ITER and beyond (Task 4)
– Remote collaboration tools enable effective
integration of international teams (Task 5)
• On-site visits by US personnel to EAST :
– Typical task member will spend ~ 1 month on
site at ASIPP
• On-site visits by EAST personnel to US:
– Experimental participation and physics
operations support for DIII-D
Summary and Conclusions
• EAST/DIII-D collaboration 2004-2011 focused on plasma control system
development and operations support
– 2004-2010 focused on plasma control system development and
operations support
– 2011-2012 began focus on scenario and control research (ITER target and
scenario development, controllability studies)
• US International Collaboration Solicitation in April 2012 resulted in GA-led
proposal for project to collaborate with EAST on scenarios and control
– 8 US institutions, ASIPP, NFRI
– Project includes 5 tasks: scenario adaptation from DIII-D/C-Mode, control
research, diagnostic/actuator development support, simulations, remote
collaboration
• Unique elements of project maximize effectiveness of collaboration:
– Extensive on-site participation, USASIPP, ASIPPUS
– Extensive remote experimental participation, including 3rd shift operation
of EAST from San Diego