Status of the advanced research under long-pulse operation in … · 2015-05-27 · Status of the...
Transcript of Status of the advanced research under long-pulse operation in … · 2015-05-27 · Status of the...
Status of the advanced research
under long-pulse operation in KSTAR Yeong-Kook Oha, J.G. Kwaka, K.R. Parka, Y.S. Baea, S.W. Yoona, Y.M. Jeona, Y. Ina,
J.M. Kwona, S.H. Honga, Y.U. Nama, Y. Chua, S.G. Leea, B.H. Parka, J. Honga, H.S. Ahna,
J.H. Choia, J.D. Konga, S.T. Kima, H.L. Yanga, H.K. Kima, D.S. Park a, H. Parkab,
W.H. Choec, Y.S. Nad, G.S. Yune, Y. Parkf, S. Sabbaghf, and KSTAR team
a National Fusion Research Institute, Daejeon, Korea
b Ulsan National Institute of Science and Technology, Ulsan, Korea c Korea Advanced Institute of Science and Technology, Daejeon, Korea
d Seoul National University, Seoul, Korea e Pohang University of Science and Technology, Pohang, Korea
f Princeton Plasma Physics Laboratory, Princeton, NJ, USA
8th IAEA TM Steady State Operation of Magnetic Fusion Devices, May 26-29, 2015, Nara, Japan
- 2 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
OUTLINE
Introduction
Mission and machine status
Highlights of the recent experiments to the steady-state operation
Long-pulse extension toward the steady-state operation
High beta operation above the no-wall limit
Development of the advanced operational modes
Validation of the low error field
ELM control using in-vessel control coils
Advanced research utilizing unique features of KSTAR
Advanced plasma control
Understanding the error fields effects with the 3D fields
Improved heating & current drive
Plasma wall interaction
Diagnostics & Modeling
Summary
- 3 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
OUTLINE
Introduction
Mission and machine status
Highlights of the recent experiments to the steady-state operation
Long-pulse extension toward the steady-state operation
High beta operation above the no-wall limit
Development of the advanced operational modes
Validation of the low error field
ELM control using in-vessel control coils
Advanced research utilizing unique features of KSTAR
Advanced plasma control
Understanding the error fields effects with the 3D fields
Improved heating & current drive
Plasma wall interaction
Diagnostics & Modeling
Summary
- 4 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
KSTAR mission and achieved key parameters
Parameters Designed Achieved
(~2014)
Major radius, R0
Minor radius, a
Elongation,
Triangularity,
Plasma shape
Plasma current, IP
Toroidal field, B0
H-mode duration
N
Superconductor
Heating /CD
PFC
1.8 m
0.5 m
2.0
0.8
DN, SN
2.0 MA
3.5 T
300 s
5.0
Nb3Sn, NbTi
~ 28 MW
C, CFC, W
1.8 m
0.5 m
1.8
0.8
DN, SN
1.0 MA
3.5 T
45 s
4.0
Nb3Sn, NbTi
~ 7 MW
C
Achieved key parameters KSTAR missions
• To achieve the superconducting
tokamak construction and operation
experiences
• To explore the physics and
technologies of high performance
steady-state operation that are
essential for ITER and fusion reactor
- 5 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
KSTAR machine status in 2015 campaign
NBI-1
5.5 MW / 50s)
170 GHz ECH
(1 MW / 50 s)
110 GHz ECH
(0.7 MW / 2 s)
30~60 MHz ICRF
(1 MW / 10 s)
5 GHz LHCD
(0.5 MW / 2 s)
XICS
FIR
ECEI
MIR
H
ECE
Thomson
Bolometer
CES / BES
MSE
SXR / IR /
Deposition
mmWI
Reflect.
105/140 GHz ECH
(1 MW / CW)
- 6 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
OUTLINE
Introduction
Mission and machine status
Highlights of the recent experiments to the steady-state operation
Long-pulse extension toward the steady-state operation
High beta operation above the no-wall limit
Development of the advanced operational modes
Validation of the low error field
ELM control using in-vessel control coils
Advanced research utilizing unique features of KSTAR
Advanced plasma control
Understanding the error fields effects with the 3D fields
Diagnostics & Modeling
Improved heating & current drive
Plasma wall interaction
Summary
- 7 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
H-mode discharge using 3 beam sources and X2 ECCD at
Bt = 3T, Ip = 0.5MA was limited at 40 sec
7
• Bt = 3.0 T (X2 170GHz ECCD), Pext ~ 4.6 MW (PNBI ~ 3.8 MW, PEC ~ 0.8 MW)
• N ~ 1.4, ~ 1.8, ~ 0.6, Vloop = 0.1~0.2 volts
• Discharge stopped by temperature interlock of outer divertor
Lack of X-point control
t=23s t=35s
Outer divertor
Divertor IRTV
- 8 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
H-mode pulse-length at 0.6 MA is extended over 40 s using
only NBI with new divertor striking target
• Ip = 0.6MA, Bt=2T, <ne> ~ 2x1019/m3, N ~ 2.1, tH=43s
• Pext ~ 4.3 MW (ENBI = 95keV/90keV/80keV), Wdia ~ 0.4MJ,
• N ~ 2.1, fNI = 82% (fNB = 63%, fBS = 19%), H89 ~ 1.7
Discharge stopped by PF electricity (MVAr) interlock
D
New target
- Central divertor striking
- 9 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Increase of plasma current up to 1 MA for 9 sec
- Ip~ 100 kA at the first plasma in 2008
- Ip~ 320 kA with circular plasm in 2009
- Ip~ 900 kA H-mode with 8s in 2012
- Ip~ 1000 kA H-mode with 9s in 2014
- Final goal : 2MA(300s)
• Much efforts on plasma control were devoted to overcome the harsh
disruption events at the high plasma current operation
I MA discharge in 2014
- 10 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
High beta(N~4) above the no-wall limit is
achieved transiently by optimal Ip/BT
Note that the KSTAR key mission is to explore physics and technology
of high performance steady state operation that are essential to ITER
and DEMO.
S. Sabbagh, IAEA 2014
bN /li = 5 bN /li = 4
n = 1 wit
h-wall li
mit
n = 1 no-wall
limit
First H-mode in 2010
Operation
in 2012
Operation
in 2011
Operation
in 2014
• By early heating for low li
• Optimizing BT & Ip
BT in range 0.9-1.5 T
Ip in range 0.4-0.7 MA
• Present maximum bN~4
(transiently) due to lack of radial
control reliability
• KSTAR is ready for RWM
instability study.
- 11 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
More details in Yongsu Na’s talk
Fully non-inductive (overdrive) is achieved
transiently.
q95 ≥ 8.5 for steady-state operation with
high βp at 0.4 MA, 2T
• 𝛽𝑁 ~ 3.0, 𝛽𝑝 ~ 3.5, H89 ~2.2, H98 ~ 1.7
transiently.
• 𝑓𝑁𝐼 = 124%, 𝑓𝑁𝐵 = 72.3%, 𝑓𝐵𝑆 = 51.8% at
𝑛𝑒 0 ~ < 𝑛𝑒 > ~1.1
• No sawtooth instabilities.
• Oscillations due to limitation of the plasma
radial position control.
#10956
0 2 4 6 8 10
-2
0
2
0
1
2
3
0
2
4
0.0
0.2
0.4
0
2
4
6
0
1
2
𝑯𝟖𝟗
𝜷𝑵
𝑫𝜶 (a.
u.)
𝐧𝐞 (#/𝐦𝟑 )
LV (V)
LV (V)
𝐈𝐏
(MA)
𝐏𝐍𝐁 (MW)
𝑻𝒊𝒎𝒆 (𝒔)
Analysis time
- 12 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Unique features of KSTAR : Low EF and ripple
Ideal machine for 3D & rotation physics
Intrinsically low toroidal ripple and low error field
• Full angle scan shows that the error field would be lower than sub Gauss (resonant
field at q=2/1 based on IPEC calculations)
• Low error field : extremely low value was confirmed (Bm,1/B0~10-5)
• Passing q95=2 (li=0.75) without (violent) MHD
Modular 3D field coils (3 poloidal rows / 4 toroidal column of coils)
• Provide flexible poloidal spectra of low-n magnetic perturbations
Error field scan based on MID RMP coils only
- 13 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Low EF is supported by accessing low q95 Ohmic
discharges without any external means
The discharge survived near q95< 2
w/o any feedforward or feedback
control of error field / RWM
q95 < 2.0
q95 ~ 3.0
Q95<2.0
800 ms
Indirect evidence of extremely low
intrinsic error field and capability for
extreme operation research in
KSTAR.
• Green : Ohmic discharge reaching q95=2.0
after passing q95=3 (li=1.0) without (violent)
MHD.
• Blue : External error field (Berror/BT~1x10-4)
makes the discharge disrupted (q95 ~3)
- 14 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Successful ELM suppression using low-n error
field uniquely in KSTAR
Mitigation Suppression
+ + - -
- - + +
- + + -
n=1, +90 phase
+ - + -
- + - +
n=2, even
+ - + -
KSTAR is unique device showing the ELM suppression at n=1 (up to 4s).
• It could related to the low intrinsic error field and low TF ripple.
• According to poloidal phasing, expanded q95 windows for ELM suppression was
tested (q95 = ~ 7.0 at 180 degree, ~6.0 at 90 degree, ~ 5.1 at mixed).
ELM suppression at n=1 (4s) ELM suppression at n=2 (2s)
Suppression
- 15 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
- + + -
Middle only
ELM suppression with only middle coil of n=2 was demonstrated.
• Extension of the ELM suppression requires a stable PCS control to maintain the
narrow operation window of q95(shaping).
• Opens the possibility of tokamak operation by (simple) external coil to the vessel.
2012 (~2s) 2014 (~5s)
Long ELM-suppression period (up to ~5s) is
demonstrated using the n=2 middle FEC coil
- 16 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
OUTLINE
Introduction
Mission and machine status
Highlights of the recent experiments to the steady-state operation
Long-pulse extension toward the steady-state operation
High beta operation above the no-wall limit
Development of the advanced operational modes
Validation of the low error field
ELM control using in-vessel control coils
Advanced research utilizing unique features of KSTAR
Advanced plasma control
Understanding the error fields effects with the 3D fields
Improved heating & current drive
Plasma wall interaction
Diagnostics & Modeling
Summary
- 17 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Strategy of the KSTAR research
New Task Forces are formed to support the new strategy and the results will
be used to accelerate the high performance long pulse operation of the KSTAR.
They are:
• Plasma control – expand the operation space of SC device and establish ITER
relevant control
• 3D physics – quantification of confinement characteristics and stability limits based
on the low field ripple and low error field which can be perturbed by IVCC
• Diagnostics – priority on profile diagnostics and improvement/development of new
diagnostics
• Modeling – validation of theory and simulation toward the predictive capability with
sets of advanced imaging diagnostics
• Heating and current drive – improvement of the existing Heating and CD system
and study of new concept for improved efficiency and possible implementation
• Plasma wall interaction and divertor – establish wall conditioning for efficient daily
operation and future steady state operation.
- 18 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Advanced Plasma Control Task Force
to resolve control issues for advanced scenario
Major roles of APC-TF are
• To resolve several important control issues that are urgent for 2015 campaign
• To establish a tactical plan and framework for advanced tokamak scenario
operations
Reliable & robust
baseline plasma control
(VDE, isoflux etc)
High performance,
steady state operation
Off-normal event &
Disruption control
MHD stability control
(NTM, RWM etc)
Flexible 3D field control
Five tasks defined for APC-TF
- 19 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Baseline plasma control
Baseline plasma control as the most important task in APC-TF
• Establish a reliable & robust isoflux control scenario
• Re-assessment of vertical stability control under the change of gap-resistance
KSTAR has similar magnetic
control systems with ITER
However, more challenging due
to poor proximity
• Similar configurations of control
coil structure
- Directly applicable to ITER
• Poor proximity of coil-to-plasma in
KSTAR
- More challenging than ITER
ITER
PF1
PF2
PF3
PF4
PF5
PF6
PF7
KSTAR
- 20 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Baseline plasma control improved significantly,
but marginal vertical controllability
#11660: Long pulse
Reproducible long pulse discharges
achieved
• Not limited by plasma shape control
• Limitations given by PFC temperature
and total apparent power (MVA)
#11721: MA plasma
MA-class discharge achieved
• However, X-point control is still need
optimization
Vertical stability was a severe issue
on attempt of MA-class plasmas
• Vertical stability was marginal
• Thus, the achieved MA discharges
were obtained by reducing plasma
elongation
- 21 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Improved control for high performance steady-
state operation
Significant and abrupt increases of plasma
performances by the advanced operation scenario Leads
to the fast radial movement
Further decoupling of IP and shape control will be
pursued
New fast radial control by using IRC coils will be
integrated into the baseline plasma control additionally.
IVC (Fast Vertical Control)
IRC (Fast Radial Control)
- 22 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Real-time control of ECCD power and mirror
position for NTM control
ECCD system is ready for real-time
applications of ST and NTM controls
• Mirror control of 170GHz ECCD
- Mirror response time: 18~20 msec
- Mirror speed: 20 cm/sec
- Vertical position: -25 +45 cm
• Power control of 170GHz ECCD
- Operated up to 50 sec
- Injection power: 0.8 ~ 1.0 MW
Both ‘search & suppression’ and ‘q-
tracking’ control algorithm have been
implemented into PCS and tested
- 23 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
3D physics task force to quantify the confinement
characteristics and stability limits
Mission:
• To investigate and quantify 3D field impacts on transport and
stability, and their limits in KSTAR (uniquely equipped with
extremely low intrinsic error fields and ripples)
3D physics related to transport :
• Energy confinement (E) (or H89 and H98) depends on 3D field
• Momentum transport () depends on 3D field
• Edge transport changes depends on ELM-suppression/mitigation
• 3-D neoclassical transport verification and validation
3D physics related to stability :
• MHD-driven 3D fields and their structures
• MHD spectroscopy
• RMP-ELM control/physics
• Disruption
- 24 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
The low level intrinsic EF may allow us an easy access to
the no-wall stability limit in KSTAR
0
5
10
0 1 2 3 4
B/B0 vs N in KSTAR (measured/linearly projected)
Typical Intrinsic EF level in Ohmic
plasmas
N
B/B0 (x10-5)
bN, no-wall ~ 2.6 (nominal)
Y. In
NF 2014
- 25 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
New installation of the In-Vessel Control Coil
Power Supply for 3D field study
IPS1 IPS4 IPS2 IPS3 IPS5
Top Botto
m Middle IRC
Patch panel IPS Power Supply (5sets)
Poor flexibility and controllability of 3D fields until 2014
• 3 DC power supply with Unipolar operation only
• 3D physics studies were heavily limited due to
configuration change was done by hands and based on
week-by-week change
Upgrade with broadband high speed power supplies
• Output : 500 V, 5 kA,
• Switching freq. : 10 kHz
• Bandwidth : dc ~ 1 kHz
IVCC coil terminals
- 26 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Newly available features of 3D field control in
2015
B F J N B
: Top-FEC PS1A
PS1B
PS4A
PS4B
: Bot-FEC
: Mid-FEC
PS2B
PS2A PS3B
PS3A
* Fully generalized 3D field configuration *
- Any n(=1 or 2), phase (), and phasing () -
# Predefined 8 sets for 3D field #
Setup Descriptions
STD-N2 Generalized n=2 fields
STD-N1 Generalized n=1 fields with
arbitrary phasing ()
STD-N1A n=1, 90 phasing fields with arbitrary phase
STD-N1B n=1, 180 phasing fields with arbitrary phase
STD-N1C STD-N1 with +90 phase shift
STD-RA Standard RWM control
STD-RB Fully generalized 3D field
STD-RC n=1 phase shooting
Goals • Provide stable operations of new systems (IVCC patch panel + IPSs)
• Provide a flexible and reliable control for newly featured 3D fields
• Real-time feedback of 3D fields such as RWM will be prepared later
- 27 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Heating and CD TF is to improve the existing
Heating/CD systems and to study new concept
Improvement of existing heating devices
• NBI-1 output power upgrade
• Steady state ECH launcher upgrade
• High power coupling in LHCD (local gas puffing, ne measurement, gap
control, PAM launcher, off-midplane launching)
• Increasing ICRF system efficiency for specific physics topics and IC wall
cleaning (ICWC)
Upgrade (near term)
• Plan of new off-axis NBI for high scenario in near term
• New 3MW, 105/140 GHz ECH system for NTM stabilization and q profile
control
• R&D of helicon wave current drive for high KSTAR operation and leading
research for DEMO
- 28 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Neutral beam injector worked as a leading heating
and CD source in KSTAR
• Max. injected beam power ~ 4.8 MW
• Longest pulse ~ 45 s at 4.3 MW (80-
95keV)
No. 3 (2014)
No. 1 (2010)
No. 2 (2012)
SECOND
Beam Line
45
cm
13 cm
Long pulse capable Positive ion based ion source
and multi-aperture plasma grid with CuCrZr
1 Beam box with 3 ion sources
Strong on-axis heating & CD (NUBEAM simulation)
Strong central rotation (CES measurement)
• ~250-300 km/s / 4 MW (H-mode) at core
• Te ~ Ti ~ 4 keV / 4 MW (H-mode) at core
1 Beam Box with 3 IS
10 m long BL
NUBEAM simulation peak ~ 0.1
- 29 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
170GHz ECH equipped by CW JAEA gyrotron and
water-cooled launcher
More details in Jinhyun Jeong’s talk
• RF output power (avg.) is 0.91MW at the window
with duration of 50 sec
• Total electrical efficiency is about 40 %
• Maximum collector surface temperature was 150
deg.
• Water cooling temperature saturated during pulse
RF power:
0.8 MW avg. (from diode detector)
VBODY: 24 kV
VK: 48 kV
Beam current:
not stabilized even for overheating
during pulse
Vac. Ion curr. 1.5×10-6 A max.
Temperature of collector surface
VAK: 42.6 45.1 kV (volt. control)
RF power:
0.8 MW avg. (calorimetric)
53 A 41 A
∆T of dummy load ~ 20 deg.
(June 03, 2014)
Water-cooled mirror
(collaboration with PPPL)
- 30 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Research activities with low power RF Heating &
CD systems
5GHz LHCD system;
• Steady-state PAM launcher design to
support high beta steady state scenario in
KSTAR
• Off-midplane LHCD launching modeling
30-60 MHz ICRF system ;
• IC wall cleaning (ICWC)
• Tungsten coating at the inner conductor in
2015 for increasing of pulse length up to 10
s at maximum 1 MW without arcing inside
VFT
R&D of helicon wave current drive
• for high operation in KSTAR and leading
research for DEMO
30
Simulation of helicon current drive in KSTAR
Tungsten coating at the inner conductor
- 31 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Plan of off-axis co-tangential NBI (’16 - ’18)
Off-axis neutral beamline
• Two 2 MW off-axis beam sources (+one 2MW on-axis)
• Ion source in vertical plane with longer dimension in
horizontal plane
• All beam-let beam focusing
• Maximum transport efficiency ~ 85%
Preliminary design of off-axis NBI
Co on-axis NBI
Co/counter
off-axis NBI
Ip
On-axis
Off-axis
Off-axis
- 32 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Goals of H&CD upgrade for high N (4~5) steady
state operation research in KSTAR
On-axis NBI-1 up to 6 MW at ~100 keV (’15-’16)
New off-axis NBI-2 up to 6 MW (’16-’18)
• 4 MW off-axis and 2MW on-axis at 95-100 keV
• Broader j(r) & p(r) for higher N limits
• N ~ 3.5 (with 2.4 MW ECCD)
6 MW ECH
• 3MW 105/140 GHz (’15-’17),
• 3MW 170 GHz (~‘20)
• Increasing flexibility of q(r) tailoring
• Te ~ Ti
• Rotation control, MHD control
4 MW LHCD and 4 MW Helicon (’19-’22)
• Efficient off-axis CD using off-midplane PAM
and TWA antenna
• N ~ 4-5 (RS with qmin > 2)
All long pulse capable up to 300 s
Off-midplane
5 GHz LHCD
0.5 GHz
Helicon
Off-axis NBI configuration
GENRAY
n//0 = 2.5
Bt = 2 T
TH2178,
500MHz,
0.8MW
CW
E3732,
508MHz,
1.2MW
CW
CURRAY
- 33 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
PWI task force to solve physics issues related to
PSI during long pulse steady state operation
Short pulse operation
Heat Flux Control
Density Control
Long Pulse Steady
State Operation
Impurity Transport
Control
Neutral Pressure Control
Wall Conditioning
Heat Load on PFCs
PFC Material Development
PFC Shaping
Impurity Source
Impurity Migration
Core accumulation/Removal
Fuel Retention
ISSUES
- 34 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Preparation of the in-vessel components for
longer pulse operation
Passive stabilizer
structure upgrade
(‘14)
Preparing for liquid helium
circulation into cryopump
(‘16) Heat load on “naturally
misaligned W-tile castellation”
Active water cooling in
divertor & limiter (‘15)
ICWC between shots (‘14~)
Pellet injector (‘16)
IVCC power supply (IPS)
upgrade
- 35 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Wall conditioning under TF field using IC wall
conditioning 35
Wall conditioning & Particle Control
• Long-pulse discharge leads large amount of retention in 2014
• Inter-shot He ICWC could reduce the accumulated retention and maintain the
retention low during a day
Accu
mu
late
d r
ete
nti
on
Shots with ICWC Accu
mu
late
d r
ete
nti
on
Shots with ICWC
Nov. 25 Nov. 26 Nov. 27
- 36 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Heat load on divertor according to ELM control
w/o RMP w/ RMP
A B
Temperature(oC)
KSTAR Div. IRTV #10880 (tm
= 6.0534 sec, tep
= 0.5 ms)
80
100
120
140
160
180
200
220
240
260
0 20 40 60 80 100 120 1400
1
2
3
4
Distance [mm]
Heat
flux
[MW
/m2]
A B
Temperature(oC)
KSTAR Div. IRTV #11211 (tm
= 10.7668 sec, tep
= 0.5 ms)
60
80
100
120
140
160
180
200
220
240
260
0 20 40 60 80 100 120 1400
0.5
1
1.5
2
2.5
Distance [mm]
Heat
flux
[MW
/m2]
1st maximum
2nd maximum
• Splitting the peak was found when RMP was applied.
- 37 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Diagnostic systems upgrade for steady-state
operation
Control related diagnostics
• For real-time measurements
• MD, Interferometer (+ECE, MSE)
• Ground system will be rearranged for decoupling of the system noise
• Fast sampling FPGA (100MHz) will be adopted for real-time fringe-jump correction
in interferometer.
Profile diagnostics
• To provide reliable & comprehensive profile data for physics study
• TS, ECE, CES, XICS, MSE
• Proto-type ITER laser for TS will be returned / new commercial laser will be installed
• For S/N improvement in TS, baffle installed on input port and EMI shield covers
• MSE system will be commissioned in the coming 2015 campaign
Two-dimensional diagnostics
• for validation of the modelling , theories & simulation
• ECEI, MIR, BES (+IR TV)
- 38 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Front optics inside cassette PEM Mirror
Beam splitter
MSE
CES
Top view
19 fibers per channel (600 um)
• 25 channels / 1 ~ 3 cm spatial resolution • Polarization-preserving collection optics shared with Charge-Exchange Spectroscopy (CES) • To solve spectral overlap of three ion sources, Stark spectrum was simulated for required
filter parameter & operating range
New diagnostic system : Motional Stark Effect
(MSE) is installed for q profile measurement
- 39 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Modeling task force
Mission:
• Lead experimental analysis using various simulation
codes and theoretical models
• Facilitate interaction between simulation and diagnostic
development
• Promote domestic & international collaborative researches
for simulation and analysis of KSTAR experiment
2015 experimental plan related to transport :
• Dedicated experiments for gyrokinetic code validation
• Develop target discharges with a single dominant
fluctuation population (either TEM or ITG)
2015 experimental plan related to MHD :
• H-mode with clear inter-ELM MHD activities
• H-mode with on-axis ECH to study internal kink
• Tearing mode control with resonant / non-resonant 𝛿𝐵
BOUT++ simulation of RMP
response in KSTAR
- 40 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Operation plan of KSTAR 2015 campaign
Extension of H-mode plasma operation range
• H-mode ~ 60 s at 0.5 MA, ~ 20s at 1 MA,
• 3D physics & ELM control (~ 10s)
• Reliable operation of advanced tokamak operation (high beta, non-inductive)
System maintenance and upgrade
• IVCC power supply (broadband) : 5 kA, 10 kHz, 0.5 kV, 5 set
• ECH/CD extension : 1 MW, 105/140 GHz
• PWI : Active cooling in PFC/Divertor, ICWC between shots
• Diagnostics : MSE, Thomson laser, etc.
FY2014 1 2 3 4 5 6 7 8 9 10 11 12
Schedule of 2015 campaign
Plasma experiments
Evacuation, wall conditioning
Machine commissioning
Magnet warm-up
Maintenance & upgrade
Magnet cool-down
Research Forum
- 41 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Superconducting
Tokamak operation
Long-pulse H-mode
and ITER pilot
Advanced scenario
related to DEMO Advanced Technology
for K-DEMO
Phase I (FY08 ~ FY12)
• Integrated control of
SC tokamak
• First plasma
• H-mode discharge
• Experimental
collaboration
Phase II (FY13 ~ FY17)
• ITER priority research
(ELM, Disruption, NTM)
• High performance
plasma study using
KSTAR intrinsic tools
(intermediate heating
power, low density)
Phase III (FY18 ~ FY22)
• Advanced operation
scenario demonstrate
• Integrated control of
profile and stability
• Research application
to K-DEMO
Phase IV (FY23 ~ )
• Stabilization and
optimization of
advanced scenario
• Technologies at
extreme
environments
Research under long-pulse H-mode discharge
•Plasma operation ~ 1 MA, 50 s, betaN ~ 2
•Heating/CD : ~ 15MW
- NBI ~ 10MW (4 MW off-axis)
- ECH/CD ~ 3MW
- RF (ICRF, LHCD, Helicon) ~ 2 MW
•Divertor/PFC : active cooled graphite tile
•Density : pellet & cryopump
•Stability control : ELM, disruption, NTM
•Electric : grid 100 MVA + MG 200 MVA
Research under advanced steady-state operation
• Plasma operation ~ 2 MA, 300 s, betaN~4
• Heating/CD : ~ 28 MW
- NBI ~ 12 MW
- ECH/CD ~ 6 MW
- RF (ICRF, LHCD, Helicon) ~ 10 MW
• Divertor/PFC : detached divertor & new material
• Density : pellet & cryopump
• Stability control : NTM, RWM
• Electric : grid 100 MVA + MG 200 MVA
Long-term operation plan of KSTAR
- 42 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
We appreciate the strong contribution on the engineering or physics
research in KSTAR from the domestic and international collaborators.
Collaborators
Korea Asia & Australia America Europe and Russia
• NFRI
• KAERI
• Seoul Nat’l U.
• KAIST
• UNIST
• POSTECH
• Hanyang U
• Daegu U.
• Ajou U.
• Jeju Nat’l U.
• Yonsei U.
• Dankook U.
• Kyungpook Nat’l U.
• Chungnam Nat’l U.
• UST
• NIFS
• JAEA
• ASIPP
• HUST
• IPR
• SWIP
• Nagoya U.
• Kyushu U.
• Australia Nat’l U.
• PPPL
• General Atomics
• ORNL
• Columbia U
• MIT
• UC Davis
• Maxplanck IPP
• CEA
• CCFE
• ENEA
• TU/e
• York U
• EURATOM-FOM
• Karlsruhe Inst. Of
Technolegy
• Politecnico di Torino
• Kurchatov Inst
• ITER
- 43 - 8th IAEA TMSSO – Yeong-Kook Oh (May 2015)
Summary
KSTAR showed remarkable progress in the long-pulse H-mode discharge
over 40s at 0.6 MA and increased current operation up to 1 MA.
High performance operations were achieved transiently such as high N
(~4.0) operation, fully non-inductive scenario (fNI ~ 124%).
The unique features of the KSTAR such as extremely low intrinsic error
field and low TF ripple could enables research exploring the limits of
confinement and instability.
In preparing the KSTAR 2015 campaign, six TFs are organized to support
the new strategy and the results will be used to accelerate the high
performance long pulse operation of the KSTAR.
This work was supported by MSIP under KSTAR project and was partly
supported by the NRF under A3 Foresight Program (No. 2012K2A2A6000443).
44
Thank you for your attention !
44
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