Vision of the KSTAR Research in ITER Era

Hyeon K. Park POSTECH on February 24, 2012 at KSTAR Conference Muju Korea Talk Why large scale clean energy source?  The ultimate option – “Fusion Power” Progress in fusion energy development and role of the KSTAR research  Brief background of the fusion energy research  Paradigm change in fusion research in recent years: steady state capable fusion devices in Asia Role of KSTAR in ITER era and K-Demo  International facility and physics basis for K-Demo New path of the fusion plasma research  “New idea” and “new methodology” Past, present, and future of “We” (population and energy)

A few Scenarios in energy world consumption rate Can we replace the fossil fuel? How and on what time scale? Global warming and CO2 emission

 CO2 concentration will trigger the global warming

 Argument is still controversial but there may be no turning point once it happens

 Needs a positive proof??

 Reduction of CO2 is a good preventive measure but the cost is not cheap unless ……..

 Need a long term plan for a clean large scale energy including fuel cell The beginning of the fusion concept

1928 Concept of fusion reaction – energy radiated by stars [R. Atkinson & F.G. Houtermans, Physik, 54 (1929)] - J. Jeans was skeptical; A. Eddington retorted: “ I suggest he finds a hotter place” 1932: Fusion reactions discovered in laboratory by M. Oliphant - Lord Rutherford felt possibility of fusion power using beam-solid target approach “moonshine” 1935 Basic understanding of fusion reactions - tunneling through Coulomb barrier – G. Gamov et al. - Fusion requires high temperatures (Maxwellian) 1939 Fusion power cycle for the stars: H. Bethe - Nobel prize 1967 “for his theory of nuclear reactions, especially his discoveries concerning the energy production in stars” Early Years of Magnetic Confinement Fusion Research

 1940s - Concept of using a magnetic field to confine a hot plasma for fusion

 1947 - G.P. Thomson and P.C. Thonemann began classified investigations of toroidal “pinch” RF discharge, eventually leading to ZETA, a large pinch at UKAEA Harwell, England in 1956

 1949 - R. Richter in Argentina claimed to have achieved controlled fusion – turns out to be bogus, but news piques interest of Lyman Spitzer at Princeton

 1950 - Spitzer conceived “stellarator” (while on a ski lift) and makes proposal to AEC ($50k) - Project Matterhorn initiated at Princeton

 1950s - Classified US Project Sherwood on controlled thermonuclear fusion

 1958 - Magnetic fusion research declassified. US and others unveil results at 2nd UN Atoms for Peace Conference in Geneva Magnetic Fusion (closed traps):Tokamak

B  Plasma in a simple torus does not have an equilibrium  Curvature and gradient in B cause single particles to drift vertically  Charge separation at the edges produces a downward E field that drives outward drift of plasma  Introduce rotational transform (helical twist) to field lines so TEXTOR (Torus-Experiment for Technology Oriented Research) drifts are compensated over several transits  External windings, geometrical B modification v

 toroidal current in the plasma Bt B itself p major radius: 1.75 m minor radius: 0.50 m plasma current: 0.5 (0.8) MA toroidal field: 2.8 T pulse length: 10 sec In Stellarators, rotational transform is created by twisting the axis or external coils (or both)  Hot plasma is confined by an intricate magnetic field  Tokamak – external magnetic field and magnetic field by a driven plasma current  Stellarator – magnetic field by complex external coils

Large Helical Device (LHD), NIFS, Japan

External diameter 13.5 m Plasma major radius 3.9 m Plasma minor radius 0.6 m Plasma volume 30 m3 Magnetic field 3 T Scientific break-even  Three large tokamak era: non-steady state device based on Cu coils (pulse length is limited by the cooling system < ~ 20 sec.)  Tokamak Fusion Test Reactor (USA) 1982-1997, Princeton Plasma Physics Laboratory, USA  Fusion power yield: Q ~ 0.3 from D-T experiment  Joint European Tokamak (EU):1983 – present, Culham, Oxfordshore, UK  Fusion power yield: Q ~ 0.7 from D-T experiment  JT-60U (Japan):1985 - present, Japan Atomic Energy Agency (JAEA), Japan  Q~1.25 extrapolated from D-D experiment

Internal view of Internal view of TFTR Internal view of JT60-U JET/plasma discharge ITER (Q=10)

 The goal is "to demonstrate the scientific and technological feasibility of fusion power for peaceful purposes".  Demonstration of fusion power yield; Q (output power/input power) ~10  International consortium (Europe, Japan, Russia, Korea, China, and India)  Total cost and beyond ~ $10 B for ~10 years and the next step is Demo

Physics basis is empirical energy confinement scaling Current status of ITER project (2011)  Construction is in progress at Cadarache, France

ITER site Device PF coil facility Admin Fusion research history and the future

JET (EU)

ITER (Q~10, 2025)

Advanced future reactor smaller and efficient Needs physics basis !! Future fusion reactor: rendering New fusion research facilities in Asia  Steady state capable devices are critical for the physics and engineering basis for the fusion plasma research  New superconducting tokamak devices are merging to Asian countries – Japan (LHD, JT-60SA), China (EAST), Korea (KSTAR) and India (SST)

SST-1, India EAST, LHD, NIFS, Hefei, Japan China

JT-60SA, JAEA, Japan KSTAR, NFRI, Korea Paradigm change in fusion research  Critical mass in fusion effort is being established in Asia  New steady state capable magnetic fusion devices are operated and/or being built in Asia (within two hour time zone)  Number of Asian scientists in fusion science is ever increasing  Engineering support in Asian sector is reliable and cost effective

 Asian Plasma Physics Organization will be effective for  Sharing physics research burden (stability, transport, current drive, material test, advanced control, etc.)  Sharing advanced technology and engineering development (advanced diagnostic system, material development, etc.)  Sharing theoretical understanding and computational facility (modeling center for fusion research) Role of KSTAR and K-Demo

2009 2020 2040

Fast Track DEMO K-Demo (EU,CN,JP,KO,US)

KSTAR It is a long Research term endeavor Device but It is our ultimate GOAL Two important roles of KSTAR International role - center for steady state physics research Human resource development for world wide fusion research Support ITER related physics issues

National role - physics basis for K-Demo design K-Demo based on current ITER scaling is a challenge (size matters !!) Physics basis of the Transport and Stability for ITER size K-Demo

New and high impact physics topics

Redefine the conventional wisdoms  What is the magic of the L/H/l/Q,.. scalings ?  Suppression or mitigation of the harmful MHD instabilities  Current drive and bootstrap current profile control  What are the key physics parameters for compact reactor?

Go with what you believe !! I am pretty tired. I think I’ll go home now What is the fundamentals of H-mode?

 L/H mode operation Circular plasma (limiter fueling and series of radial low resistors – L-mode Diverter plasmas (x-point DIII-D, R. Groebner, et al. fueling and series of high PPFC 44, 2002 resistors – H-mode  Reduction of recycling with Li and core heating Energy and particle flux (in and out) – to guess the transport physics NSTX, M. Ono, et al. FED, 2010 What is the fundamentals of ITB?  Super/RS/ERS mode operation Heavy recycling control (Li) and core heating profile - Source and Loss in power balance

 Energy and particle TFTR, Efthimion, et al. flux (in and out) at a flux surface is not known – measures

only the difference JT-60U, Fujita, et al . PRL 1997

TFTR, D. Mansfield, et al. Phys. of Plasma. 1996 New idea and new methodology

 Remaining physics issues Stethoscope and engineering challenges require new path Physics - experimental verification of the hypothesis and assumptions is essential for the advancement  Comprehensive visualization of magnetic reconnection process is an example Engineering – Discovery/ Invention of new materials to reduce the cost of the fusion reactor Magnetic resonance imaging Example: Classical sawtooth oscillation  Sudden break up of a stable magnetic surface in a time scale much shorter than energy transport time  Sawtooth oscillation is a magnetic self-organization via magnetic reconnection process

H. Park (PRL, 2006) Simultaneous measurement (~400 channels)

 World first observation of core and edge MHD instabilities simultaneously  Core – sawtooth

 Edge - ELMs  In 2012, POSTECH will attempt world first 3-D measurement in fusion devices  Two imaging systems separated on toroidal plane

G. Yun (PRL, 2011) Summary Long but significant progress has been made in high temperature plasma research Progress is clear from the early skepticism of the star power to ITER Paradigm change in the fusion research is evident

Two important roles of KSTAR International research device for ITER physics and human resource development Physics basis for K-Demo

New path for advanced fusion reactor design “New Idea” and “New Methodology” are essential