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

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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 direction on threshold power

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Inner strike point control

Inner strike point control

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

Vertical instability

Tearing 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 night-time 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, USASIPP, ASIPPUS –  Extensive remote experimental participation, including 3rd shift operation

of EAST from San Diego