26th IAEA Fusion Energy Conference, Oct. 17-22, 2016, Kyoto, Japan

Overview of the KSTAR Researchin Support of ITER and DEMO
October 17th, 2016

Yeong-Kook Oh1
On behalf of
KSTAR TEAM and Research Collaborators
1National Fusion Research Institute (NFRI), Daejeon, Korea

We appreciate all the research collaborators for theircontribution to KSTAR program
EUROfusion
F4E
ITER
IPP
CCFE
EFDA-JET
CEA-IRFM
ENEA
WignerTU/eYork UCRPP-EFPL
KIT
Politechnico duTorinoInternational Collaborators

DOE
PPPL
ORNL
General Atomics
Columbia U.
MIT
UCSD
UC Davis
LBNL
Princeton U.
Wisconsin U.
D-TACQ

NRC, KI
JINR
Gycom
PELIN
QST
NIFS
Nagoya U.
Kyusu U.

ASIPP
SWIP
HUST

Korea Domestic
Collaborators

IPR

ANU

MSIP
SNU
Hanyang U
Yonsei U
Ajou U
NST
NRF
NFRI
ITER KO
KAERI
KAIST
CNU
Dankook U
UST

IAEA FEC 2016, KSTAR_YKOH

KAPRA

POSTECH
UNISTKNU
Daegu U
Pusan U
Chonbuk U
GIST
Jeju U- 2-

Fully non inductive high beta (βP > 3) discharge
and physics validation of sawtooth and turbulencep High βP steady-state (fully non-inductive)discharge and extension to 70s

p Physics validation of q0 ≥ 1.0 in MHD
quiescent time after the sawtooth crash• 30 yrs ago, at Kyoto IAEA, it was reported
that q0 ≅ 0.75 ± 0.03 (TEXTOR and TFTR)• In 2016, KSTAR validates q0 ≥1.0
MSE measured
q0 ≅1.0 ± 0.03
but uncertainty
from Er and κ
makes q0 value
uncertain

q Nonlinear interaction btw ELM & turbulent
eddies induced by RMP
ELM

Turbulence

BT=2.9 T, IP=0.4 MA, PNBI=5.0 MW, PECH~ 0.8 MW,
fNI ~ 1, fbs < 0.5, βp > 3, βN ~ 2, H89 ~ 2.0, li ~ 1.2

IAEA FEC 2016, KSTAR_YKOH- 3-

OUTLINEqIntroductiono Research directionso Unique research tools on KSTAR and role for the test bed
for ITER and beyondqResearch highlights of KSTARo Extension of H-mode and high performance discharges intolong pulse and steady-stateo Reliable ELM crash free operation and analysis
o Exploring confinement and stability issues using KSTAR
unique research toolsq

Future plan & summary
IAEA FEC 2016, KSTAR_YKOH- 4-

Research directions and key parameters in KSTAR
q Research directions of KSTAR• Extend the reference H-mode and highperformance discharge into long-pulse
utilizing SC magnets• Explore confinement and stability issues
using the KSTAR uniqueness• Exploit new stable high-beta and advanced
plasma operation regime for K-DEMO(2016)

q Key parameters of KSTAR, ITER & K-DEMO
KSTAR

ITER

K-DEMO(achieved)(Baseline)(Option II)

Major radius, R0 [m]

1.8

6.2

6.8

Minor radius, a [m]

0.5

2.0

2.1

Elongation, κ

2.0 (1.8)

1.7

1.8

Triangularity, δ

0.8

0.33

0.63

Plasma shape

DN, SNSN

DN (SN)

Plasma current, IP [MA]

2.0 (1.0)

15

> 12

Toroidal field, B0 [T]

3.5

5.3

7.4

H-mode duration [sec]300 (70)

400

SS

βN

5.0 (4.3)

~ 2.0

~ 4.2

Parameters

fbs

~ 0.6

Superconductor

Nb3Sn, NbTi

Nb3Sn, NbTi

Nb3Sn, NbTi

Heating /CD [MW]~ 28 (10)

~ 73

160

C, W

W

W

~0.5

~ 2.1

PFC
Fusion power, Pth [GW]

IAEA FEC 2016, KSTAR_YKOH- 5-

KSTAR has unique research tools as the test bed for ITER and
K-DEMOq Lowest intrinsic error field (δB/B0 ~ 1x10-5) andlow magnetic ripple (~0.05%)
o Lower L-H transition threshold powero High beta operation accessible without error fieldcorrection
Y. In (NFRI) NF2015
q ITER relevant In-vessel control coils (IVCC) for ELM
controlo Three poloidal rows (top / middle / bottom) same as
ITERo Stable ELM crash suppression/mitigation at n=1, 2
and mixed
Y.M. Jeon (NFRI) PRL2012

q Advanced 2D/3D imaging diagnostics
o 2D/3D ECEI, MIR, BES, etc
o New physics from the measurement of turbulenceand MHD instabilities
G.S. Yun (POSTECH) PRL2011

IAEA FEC 2016, KSTAR_YKOH- 6-

Status of heating & current driving systems in KSTAR
Heating &CD in 2016
~10 MW
NBI
5.5 MW, 100 keV(on-axis, ~70s)
ECH/CD
1 MW, 105/140 GHz
1 MW, 170 GHz

Goal of H&CD
~ 28 MW, 300s

NBI-1

Long pulse
operation of NBI

NBI-2

LHCD
0.5 MW, 5 GHz

ECH/CD
2 MW, 105/140 GHz
4 MW, 170/140 GHz
LHCD
5 GHz, 4 MW
ICRF/ICWC
30-60 MHz, 2 MW

ICRF
2 MW, 30-60 MHz
Helicon CD
0.3 MW, 0.5 GHz

NBI (~’18)
6 MW, 100 keV, on-axis
6 MW, 100 keV, on/off-axis

Water-cooled steering
mirror (collab. with PPPL)

Prototype Helicon CD &fully active LHCD antenna

Helicon CD
0.5 GHz, 4 MW

• Fueling (SMBI, pellet, divertor puffing)• In-vessel cryo-pump• Wall conditioning under TF field• Active water cooling on PFC• Castellated PFC/Divertor tile
IAEA FEC 2016, KSTAR_YKOH- 7-

Diagnostics systems developed through collaboration
q Survey Diagnostics

q Imaging Diagnostics

q Profile Diagnostics
Thomson Scattering

ECEI

Magnetic Diagnostics

ECE Radiometer

MIR

Edge Probe

CES / XICS

BESInterferometers

Visible TV

FILD

Tangential & Div IRTVVUV Spectrometer

Soft X-ray Imaging

Deposition Probe

Imaging Bolometer

Visible Filterscope

MSE / iMSE

TU/e

Reflectometer
Reciprocating Probe

ASIPP

ASIPP

Neutron Spectrom.
Ti & rotation profile(CES / XICS)

Te profile(ECE & Thomson)

q profile(MSE)#16498

Turbulence(ECEI)

2500 ms (w/ ITB)
4500 ms (w/o ITB H-mode)
6500 ms (w/o ITB L-mode)q

ECE
Thomson

psi_n

IAEA FEC 2016, KSTAR_YKOH- 8-

OUTLINEqIntroductiono Research directionso Unique research tools on KSTAR and role for the test bed
for ITER and beyondqResearch highlights of KSTARo Extension of H-mode and high performance discharges
into long pulse and steady-stateo Reliable ELM crash free operation and analysis
o Exploring confinement and stability issues using KSTAR
unique research toolsq

Future plan & summary
IAEA FEC 2016, KSTAR_YKOH- 9-

Fully non-inductive current drive discharge has beenachieved with high poloidal beta (βp > 3)
q Fully non-inductive discharge without limits in flux and MVA
o fNI ~ 1, fBS < 0.5, βp > 3, βN ~ 2, H89 ~ 2.0, li ~ 1.2,oBT=2.9 T, IP=0.4 MA, PNBI =5.0 MW, PECH~ 0.8 MW

q Early termination due to safety interlock (heat load on poloidal limiter)o Increases fast ion loss from neutral beam at lower plasma current

Temperature rise in poloidal limiterat long pulse operation (IRTV)

J

ψN

!
!
J EFIT ⋅ B / B0

02
51

ψN

01
5
0

q

poloidal angle [deg]52!
!
J BS ⋅ B / B003

05

Particle
flux
30

30

25
52
Poloidal Limiter
Ip=400kA
Ip=600kA

02

A
0

B

C

51
01
5

0

25

20

20

15

15

10

10

5

5

0
05- 0
-50
0220
22
0200
02
0180
81
0160
61
0140
41 120220
0220
210120
120
140
160
180
200
22 0200
02 0
81 0
61 200041 220
021
140
160
180
180
160
140
120

0

]toroidal
ged[ elgangle
na lad[deg]
iorot

q

(EX/P4-1) S.W. Yoon (NFRI), et al

50

03]ged[ elgna ladiolop<J||B/B0> (MA m-2)

Te, Ti (keV)Te, TiψN

IAEA FEC 2016, KSTAR_YKOH

IP=600 kA

IP=400 kA

Good agreement withprompt loss calculation
Courtesy of K. Shinohara (QST)- 10 -

H-mode discharge with highly non inductive current
drive has been extended over 1 min (~ 70s)
q Problem of heatload on poloidal limiter was resolved by reduced NBI power (5.1 à 3.8 MW)
and increased gap between plasma and PFCoofNI ≤ 1, βp : 2.4 ~ 1.9, βN ~ 1.8 ~ 1.5, WMHD ~ 0.3 – 0.25 MJ
BT=2.5 T, IP=0.45 MA, PNBI =3.8 MW, PECH~ 0.8 MW

q However density and loop voltage increased slowly from 30s due to un-controlled striking
point à need density control and striking point control#17321

IP=0.45 MA
BT=2.5 T
PNBI=3.8 MW
PECH=0.8 MW
Vloop~0.0-0.1 V
ne,avg~2.7 x1019 m-3

ne increase
WMHD decrease

WMHD~0.3-0.25 MJ
βN~1.8-1.5
βp~2.4-1.9

time (s)at t=20s
at t=30s
at t=70s

Degradation may comes fromshift of outer strike point

EX/P4-1, S.-W. Yoon (NFRI), et al
IAEA FEC 2016, KSTAR_YKOH- 11 -

Plasma control improvement for Mega-ampere
discharge and ITER baseline scenario
q Advanced control techniqueintegrations developed for ITER
baseline scenario research in KSTAR

q Improved ECH-assisted startup using
Trapped Particle Confinemento “Decoupled” Z control in the frequency
responses
o Real-time PF feedforward calculation w/ plasma
resistance trackingo MIMO X-point controller
ITER-similar shape(scaled for KSTAR)(EX/P4-14) J. Lee (SNU), et al

q Plasma control improvement to accessMega-ampere current (1 MA) H-mode

parameter#16380t=6.4sScaledITER BS

βΝ

2.0

1.8

q95

3.2

3.2

κ

1.8

1.9

Ip/aBT

1.0

1.4

Courtesy of M. Lanctot (GA), et alt (sec)(EX/P4-12) S.-H. Hahn (NFRI), et al
IAEA FEC 2016, KSTAR_YKOH- 12 -

KSTAR observed ITB formation in L-mode discharge
with the confinement comparable to that of H-mode
ITB @ 2.5 s
H-mode @ 4.5 s

Ion temperature (keV)q ITB (internal transport barrier) formed at electron and ion
temperature profiles• ITB could last up to 10s (> 40 𝝉E).
q Significant improvement in confinement (stored energy
and 𝜷N) with comparable to that of H-mode discharge

ITB foot

H-modePedestal

𝝍𝑵

Safety factor

ITB @ 2.5 s
H-mode @ 4.5 s

weaker magnetic
shear at ITB
ITB foot

𝝍𝑵

Courtesy of J. Chung, H.S. Kim (NFRI)
IAEA FEC 2016, KSTAR_YKOH- 13 -

Higher βN and lower q95 discharges are underdevelopment for the stability limit researchq KSTAR H-mode equilibria have reachedand exceeded the computed n = 1 ideal
no-wall stability limito Highest βN = 4.3, βN/l i =6.3
o High βN > βNno-wall operation mostly limitedby 2/1 mode (βN =3.3 sustained 3 s)

q Attempt lower q95 (< 2.3) discharge tominimize harmful MHDs (low m/n)o Low m/n rational surfaces are pushed out
o Removal of strong n=3 mode brought theconfinement recovery (red shade).

q 95=2.25

n=4
n=3
n=2
n=1
Y.S. Park, S. Sabbagh (Columbia U), et al, NF 2013
(EX/P4-2), Y.S. Park (Columbia U), et al
IAEA FEC 2016, KSTAR_YKOH

Courtesy of J. Kim (NFRI) et al- 14 -

Development of hybrid and reverse shear scenarios
for high confinement regime
q In KSTAR, hybrid mode was achieved bybeam timing control in H-mode, andsustained for 5-8 s without any harmful
MHD activities• G (= βNH89/q952 ) ~ 0.38,• H89 < 2.3, βN < 2.7 at q95 = 3.8-4.5• It was close to ITER baseline (G = 0.4) andabove ITER steady state (G = 0.3)

q Weak reverse shear profile achieved byrevered Ip operation due to strong countertangential NBCD
Reversed Ip: J║
Counter- NBCD
Hollow J profile
Weakly reverse
magnetic shear

q profile

ITER level
Normal Ip: J║

Co- NBCD
peaked J profile

Courtesy of Y.S. Na (SNU), et al

Courtesy of J. Kim (NFRI) et al
IAEA FEC 2016, KSTAR_YKOH- 15 -

OUTLINEqIntroductiono Research directionso Unique research tools on KSTAR and role for the test bed
for ITER and beyondqResearch highlights of KSTARo Extension of H-mode and high performance discharges
into long pulse and steady-stateo Reliable ELM crash free operation and analysis
o Exploring confinement and stability issues using KSTAR
unique research toolsq

Future plan & summary
IAEA FEC 2016, KSTAR_YKOH- 16 -

Demonstration of extremely reliable ELM crashsuppression (~ 10 s) under static and rotating RMP
q Robust ELM crash suppression is one of the high priority issues in ITER with W wall.
q Recently, KSTAR has demonstrated very stable ELM crash suppression under static androtation of the RMP (resonance magnetic perturbation).
• Wider q95 = 5±0.25 (relaxed constraint), Rx or triangularity dependance (Delta_lower ~ 0.74 ± 0.04)
n=1 (+90 phasing) full RMP at q95~5.0 [~2kA/turn]

n=1 full RMP under 360 degree rotation

Suppression ~ 10s
3600 rotation

ITER Invessel Coils

Y.M Jeon (NFRI), PRL
2012

IAEA FEC 2016, KSTAR_YKOH(Post-Deadline) Y.M. Jeon (NFRI), etal- 17 -

Profile of divertor heat flux has ben measured during
ELM-crash suppression at static and rotating RMP
Vacuumq Heat flux profile shows very
different splitting pattern,
depending on phasing andcoil configuration
q Intentionally misaligned
RMP configurations would
spread the divertor heat
fluxes in a wider area (insupport of ITER )IR cameraΔφUL= 90o
(resonant)Plasma response (IPEC)

Measuredheat flux

IR camera++-- ++ -- - ++ -- ++++-- ++ -Heat flux splitting by misaligned RMP configuration(EX/P4-24) H.H. Lee (NFRI), et al(EX/P4-30) J. Ahn (ORNL), et al
Courtesy of A. Loarte (ITER) , et al
IAEA FEC 2016, KSTAR_YKOH- 18 -

Plasma surface interaction of metal divertor using
castellated Tungsten blockq Install and exposure of castellated
tungsten block• Castellated W tile with different leadingedge and shape installed on divertor• Heat flux and temperature are monitored
using IRTV (3x optical zoom)q The heat load on divertor is evaluated using
IRTV (tangential & vertical)
q A complete set of deposition profiles inside
the gap of castellated blocks were analyzed.
370
simulated temperature
exposure time
10 ms
30 ms
80 ms

360
350

temperature
Temperature(deg(0C)C)

340
350
330

Diverter
IRTV

IR temperatureframe 478 (10 ms)
frame 480 (30 ms)
frame 485 (80 ms)
frame interval=10 ms

320
310
300
290
300
280
270
260
250

250
240
230
220

0

5

10

15

20

25

30

distance (mm)Temp. profile after exposure

Divertor IRTV
(w/ optical zoom)

Deposition depending on the heightof leading edge
Castellated W tile
IAEA FEC 2016, KSTAR_YKOH(EX/P4-21) S.H. Hong (NFRI), et al- 19 -

Research on the retention and high-Z impurity
transport in KSTAR
q Hydrogen retention on carbon wall
depends on plasma current and pulse
length.

Fuel retention on carbon tile according to plasma current
and pulse length
Pulse
length• Retention is proportional to pulse lengthand issues in long pulse discharge.

Plasmacurrent• Wall conditioning between shotq Ar impurity accumulation control using
ECCD and RMP

L-mode• On-axis ECCD suppressed coreaccumulation of Ar• Hollowed profile in L-mode and flat profilein H-mode

H-mode• Kr injection changed ELM features(mitigation and suppression)(EX/P4-18) J. Hong (KAIST), et al
IAEA FEC 2016, KSTAR_YKOH- 20 -

OUTLINEqIntroductiono Research directionso Unique research tools on KSTAR and role for the test bed
for ITER and beyondqResearch highlights of KSTARo Extension of H-mode and high performance discharges
into long pulse and steady-stateo Reliable ELM crash free operation and analysis
o Exploring confinement and stability issues using KSTAR
unique research toolsq

Future plan & summary
IAEA FEC 2016, KSTAR_YKOH- 21 -

Validation of q0 ≥ 1.0 in MHD quiescent time after thesawtooth crashq 30 yrs ago, at Kyoto IAEA, it was reported thatq0 ≅ 0.75 ± 0.03 (TEXTOR and TFTR)
q 20 yrs ago, q0 ≅ 1.0 ± 0.03 was reported (DIII-D)
and later raised issue of Er effectq 2016, KSTAR validates q0 ≥1.0
q MSE measured q0 ≅1.0 ± 0.03 but uncertainty
from Er and κ makes q0 value uncertain
Required absoluteaccuracy is ± 0.01 for
q0 ≥1.0 after the crash(challenging !!)(EX/P4-27) J. Ko (NFRI), et al

q Growth and decay of the tearing
mode Exp. within q=1 surface•

Sawtoothing discharge : tearing
mode evolve (e.g. 3/3 to 2/2, 1/1)•

Non-sawtoothing discharge : nochange(EX/P4-3) H. Park (UNIST), et al
IAEA FEC 2016, KSTAR_YKOH- 22 -

Theoretical and experimental validation of the ELM
crash suppression mechanism
q Nonlinear interaction btw ELM & turbulent
eddies induced by RMP
o Broadband turbulence induced by RMP
damps the ELM amplitude

q Exploring optimum phasing angle andamplitude for reliable ELM crashsuppression• Fixed top/bottom at 5kA/turn• Phasing and amplitude of middle coil
• Experiments well match with modeling• Plasma response calculation is necessary
over vacuum calculation

ELM

Turbulence

J. Lee (UNIST), PRL 2016
(EX/P4-15) J. Lee (UNIST), et al

Courtesy of J.K. Park (PPPL) et al
IAEA FEC 2016, KSTAR_YKOH- 23 -

KSTAR has an excellent environment for Neoclassical Toroidal
Viscosity (NTV) physics research using reliable rotation profiles
q Plasma rotation highly important for tokamak stability and confinement• If sufficiently strong, this rotation could provide stabilization and improved performance in
ITER and future devices••

Effect of localized NTV on toroidal rotation profile : (TH/P3-11) J. Seol (NFRI) et al
Code verification and validation in most quiescent plasmas : (TH/P1-6) J.K. Park (PPPL) et al
Direct measured rotation profile andNTV offset

Phase dependence on NTV magnetic braking
q95~6

o 0-phasing : quiescent, No density pump-out
o -90 phasing : resonant configurationo 90 phasing : transitiono Final saturated rotation profile at n=2 leadto strong rotation shear at edge

(EX/P4-33) S. Sabbagh (Columbia U.) , et al(EX/P4-9) K. Kim (KAIST), et al
IAEA FEC 2016, KSTAR_YKOH- 24 -

L-H transition threshold power (Pth) depends on thelevel of error field in fusion devices
q The dependence of Pth on the applied error field (δB/B0) was reported by DIII-D team (2011).
q Pth dependence on n=1, 2 error field has been measured In KSTAR,• Pth in KSTAR is much less than the Martin scaling (Journal of Physics, 2008) at single modeerror field (δB/B0 < 2.7 x 10-4), which is level of intrinsic error field in conventional devices.
• However, in mixed mode error field case, strong dependence of Pth on δB/B0
q It showed that the n=2 error field is not negligible compared to n=1 error field to get H-mode within
limited heating power such as in early state of ITER operation.
• For ITER, the test blanket module is one of the sources of error field and need a clear mapping of δB.
19

KSTAR, 0.6MA, 1.8T, q95~4.1, ne= 2x10 mn=1
n=2PTH, scal08

1.6

4n=1(fixed) + n = 2

q = 3.4(KSTAR)3

1.2

Martin scalingfor KSTAR

1.0

1

-3

(DIII-D)

2

Martin scalingfor DIII-D

KSTAR data

1

0.8

0

19

q = 4.0 DIII-D n=3 ( 1.1-1.3MA, 1.7T, ne = 2.7-3.1x10 m )PTH, scal08

Pth [MW]Pth [MW]

1.4

-3

2

3

4

0

5

1

2

3

4

5

6

7

-4

-4

δB/B0 (10 )δB/B0 (10 )(EX/P4-4) W.H. Ko (NFRI), et al

P. Gohil (GA), et. al, NF 51 103020 (2011)

IAEA FEC 2016, KSTAR_YKOH- 25 -

OUTLINEqIntroductiono Research directionso Unique research tools on KSTAR and role for the test bed
for ITER and beyondqResearch highlights of KSTARo Extension of H-mode and high performance discharges
into long pulse and steady-stateo Reliable ELM crash free operation and analysis
o Exploring confinement and stability issues using KSTAR
unique research toolsq

Future plan & summary
IAEA FEC 2016, KSTAR_YKOH- 26 -

Major system upgrade toward high beta long pulse
operation (~2021)
q Up to 2020, research campaigns to explore the optimum operation regime for steadystate and high beta using NBI-2 : Confinement, Stability, Bootstrap current, etc.
q From 2021, In-vessel components upgrade for the optimized plasma volume andshapeq Optimized divertor configuration with new first wall material (compatible for k-DEMO)q Optimum current drive configuration: high field side LHCD, Helicon CD, top launching
ECCD
2008
First plasma• Research on long pulse &steady-state H-mode
operation• Stable ELM–crash free
operation• Study of MHD dynamics

2016

2018

2021

NBI-II

Major upgrade• Stable high beta regimes
explored using NBI-II (Ti ~10 keV)• In-depth physics using
advanced diagnostics• Prepare major upgrade
IAEA FEC 2016, KSTAR_YKOH• Advanced operation
scenarios (k-DEMO
relevant)• Advanced divertor
research• Advanced current drive- 27 -

Upgrade plan of heating system for high performancesteady-state operation
q Heating system upgrade to ~28 MW•

NBI : 5.5 MW à total 12 MW (‘18) : on & off-axis,
collab. KAERI, QST, PPPL••

ECH/CD : 105/140 GHz (2 MW) & 140/170 GHz(4 MW) collab. QST, PPPL, KAERILHCD : 5 GHz (4 MW, PAM or HFS launch) collab.
CEA, MIT, POSTECH•POSTECH•

Courtesy : J.M Park (ORNL)

Helicon CD : 0.5 MHz (4MW) collab. KI, SLAC,ICRF : 30-60 MHz, optimize for IC wall condition
NBI-1

NBI-2
Fusion performance, GG = β NH89/q952 = 0.92
(cf: G~0.5 for ITER)

Near TermLong TermPNB On/Off

4/4 MW

6/4 MWPEC (X2)

2.4 MW

4.8 MW

PLH-

3 MW (n//=2.0 from off-mid)

Ip/BT

0.6 MA/1.8 T

1 MA/1.8T

q95

5.2

3.1

Shape

SN

DN

𝞫N

3.45

4.2

fNI/fBS

1.0/0.5

1.1/0.47

H89

2.2

2.1

qmin

1.54

1.63

G=H89𝞫N/q952

0.3

0.92

Te/Ti

1.31

1.1

IAEA FEC 2016, KSTAR_YKOH- 28 -

Contribution to IAEA FEC from KSTAR collaborators[Overview & scenarios]• OV/2-3
Y.K. Oh
KSTAR Overview• EX/P4-1 S.W. Yoon High beta operation• EX/P4-12 S.H. Hahn
Vertical stabilization control• EX/P4-13 H.S. Kim
Physics based profile control• EX/P4-14 J.W. Lee
Trap Particle Confinement• EX/P4-53 H. Lee
EBW assisted startup, VEST
[3D field, ELM & NTV]
• EX/1-3
Y. In• EX/10-3 G.S. Yun• TH/P3-11 J. Seol
• EX/P4-33 S. Sabbagh• TH/P1-28 J. Kim• EX/P4-4 W.H. Ko• EX/P4-7 M. Kim• EX/P4-9 K. Kim• EX/P4-15 J.H Lee

Nonaxissymetric
ELM & global structure
NTV & rotation
NTV profile & 3D
Magnetic perturbation
L-H treshold under 3D field
ECEI ELM observation
Magnetic braking
Edge turbulence interaction[Divertor & PSI]
• EX/P4-21 S.H. Hong• EX/P4-24 H.H. Lee• EX/P4-25 M.K. Bae• EX/P4-30 J.W. Ahn• TH/P6-5 W. Choe

Deposition inside gaps
Divertor target heat load
Heat flux to first wall
Diverter heat flux & 3D
Divertor heat flux & 3D

[Fusion engineering]• FIP/3-3
J. Kang• FIP/P7-15 J. Park

Algorithm for K-DEMO
Structure analysis for K-DEMO[MHD, EP & disruption]• EX/P4-3 H. Park
Sawtooth crash• TH/P1-17 A. Aydemir Disruption• EX/P3-19 D. Orlov
Perturbation & MHD• EX/P4-2 Y.S. ParkMHD stability at high betaN• EX/P4-5 J.Kim
Destabilizing Edge instability• EX/P4-6 Y. In
Locked mode dissipation• EX/P4-8 J.G. Bak
Halo current• EX/P4-10 S.G. Lee
Long-lived mode
• EX/P4-20 W. Lee
Ion-scale turbulence• EX/P4-26 J.H. Kim
Alfven Eigenmode• EX/P4-28 M. Cheon
Runaway Runaway electron• EX/P4-29 C.M. Ryu
TAE• EX/P4-22 J.G. Kwak
Neutron yield[Confinement & transport]• TH/P2-25 J.Y. Kim
Energy confinement• EX/P4-16 S. Ko
Toroidal rotation & ELM• EX/P4-23 K.C. Lee
Poloidal asymetry on ELMs
• EX/P4-17 Y. Shi
Rotation reversal & transport• TH/P2-24 Y.S. Na
Particle transport• EX/P4-19 D.H. Na
Intrinsic rotation reversal• EX/P4-27 J. Ko
Current profile evolution• EX/P4-18 JH. Hong
Ar transport• TH/8-3
H.G. Jhang Zonal flow and edge collapse• TH/P3-13 H.H. Kaang Momentum transport• TH/P3-25 T.S. Hahm ExB shear• TH/P3-27 M. Leconte Zonal flow & RMP• TH/P3-29 S.S. Kim
Turbulence BOUT++• TH/P3-32 C.Y. An
Energy non-trapping

IAEA FEC 2016, KSTAR_YKOH- 29 -

Summary
KSTAR, as an international collaboration device, has directions to resolve the scientificand technical issues in developing steady-state high beta and advanced plasma
operation regime for ITER and K-DEMO.
KSTAR is well engineered superconducting tokamak with several unique research tools
as a test bed for ITER and K-DEMO ;• lowest intrinsic error field and ITER relevant in-vessel control coils (top/middle/bottom)• Advanced 2D/3D imaging diagnostics and long pulse heating/CD systems
Remarkable progress in plasma operation and physics research has been conductedaccording to strong contribution from domestic and international collaborators.
• extension of H-mode discharge into large Ip (1 MA) and long pulsed (up to 70s)
• developing stationary high performance discharge (high beta and ITB operation)• robust ELM-crash suppression (~10sec) at n=1 under static and rotational RMP.
• theoretical and experimental validation of MHD instabilities (sawtooth and ELMs)
Improved research long pulse & high performance operation (Ti ~ 10 keV) and in-depth
research are planned using NBI-II installation (2018) and in-vessel components upgradein divertor and current drive (2021).
Your recommendation and collaboration on KSTAR are very welcome everytime.
IAEA FEC 2016, KSTAR_YKOH- 30 -

Thank you for your attention !

IAEA FEC 2016, KSTAR_YKOH

31

31- 31 -

Back Up Slides

IAEA FEC 2016, KSTAR_YKOH- 32 -

Upgrade plan of the heating and CD for high performancesteady-state operation
q 12 MW NBI systems• 8 MW on-axis and
4MW off-axis• Broader j(r) & p(r) for
higher βN limits
q 6 MW ECH/CD• 4MW 105/140 & 2 MW
140/170 GHz• Higher Te/Ti, q(r)tailoring, Rotation
control, MHD control
q 4 MW LHCD and 4MW
Helicon• off-axis CD & βN ~ 5(RS with qmin > 2)
q Expected highperformance discharge•

IAEA FEC 2016, KSTAR_YKOH

G = βNH89/q 952 = 0.92
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