Overview of KSTAR - IAEA NA · Overview of KSTAR Initial Experiments National Fusion Research...

Overview of

KSTARInitial Experiments

National Fusion Research InstituteKSTAR Research CenterM. KWON on behalf of KSTAR Team

OV/1-1

KSTAR Team and Collaborators

§ National Fusion Research Institute : YK Oh, WC Kim, HL Yang, JH Kim, SW Yoon, YM Jeon, SH Hahn, HK Na, KR Park, JH Lee, SH Hong, A England, ZY Chen, Y Yaowei, JG Bak, SG Lee, SH Seo, DC Seo, WH Ko, YU Nam, JI Jeong, ST Oh, KD Lee, KI Yoo, BH Park, DK Lee, JC Seol, DS Lee, JW Yoo, H Lee, SW Kim, JG Lee, JS Hong, Y Chu, IS Woo, YO Kim, KP Kim, WS Han, Y Yonekawa, SH Park, MK Park, MK Kim, SI Lee, WL Lee, SH Baek, TG Lee, JS Park, KW Cho, DS Park, J Ju, KM Moon, JS Kim, HS Kim, HK Kim, KM Kim, EN Bang, KS Lee, HT Kim, YM Park, HJ Lee, SW Kwak, NH Song, YB Jang, HT Park, YS Bae, JS Kim, M Joung, SI Park, HJ Do, YS Kim, JH Choi, JK Jin, DG Lee, CH Kim, JD Kong, SR Hong, YJ Kim, ST Kim, NY Jeong, DS Lim, JY Kim, JM Kwon, SS Kim, HG Jang, L Terzolo, SM Lee, S Tokunaga, K. Miki, JC Kim, DR Lee, S Sajjad, I Chavdarovski, JH Sun, L Wang, M LeConte

§ Korea Atomic Energy Research Institute : JG Kwak, SH Jeong, SJ Wang, SH Kim, DH, Chang, BH Oh§ Seoul National University : YS Hwang, YS Na, HS Kim, KM Kim, DH Kim§ Pohang University of Science and Technology : H Park, MH Cho, CM Ryu, W Namkung§ Korea Advanced Institute of Science and Technology : W Choe, CS Chang, SH Lee§ Hanyang University : KS Chung, YH Kim, HJ Woo, JH Sun § Daegu University : OJ Kwon § Soongsil University : CB Kim § Ajou University : SG Oh § Kyungpook University : KW Kim§ University of California at San Diego : P Diamond § Oak Ridge National Laboratory : D Hillis, RJ Colchin (deceased), JW Ahn§ Princeton Plasma Physics Laboratory : D Mueller, L Grisham, JK Park, TS Hahm§ General Atomics : A Hyatt, M Walker, D Humphrey, J Leur, N Eidietis, AS Welander, GL Jackson, J Lohr§ Columbia University : S Sabbagh, YS Park § Fartech : JS Kim, YK In§ Japan Atomic Energy Agency : T Hatae, K Watanabe, M Dairaku, M Kikuchi, K Sakamoto§ National Institute of Fusion Science : K Kawahata, Y Nagayama, K Ida, T Mutoh, B Patterson, N Narihara, T Seki, S Kubo § Kushu University : A Mase, N Yagi§ ASIPP : B Wan, Y Shi§ National Cheng Kung University : F Cheng, K Shaing§ Australian National University : M Hole

Contents

I. INTRODUCTION

II. KSTAR AS A STEADY-STATE DEVICE

• Super-conducting Magnets• Heating & Current Drive• Active Plasma Control• Plasma-Wall Interaction

III. COLLABORATION

IV. FUTURE PLAN

V. SUMMARY

Overview of


I. INTRODUCTION

23rd IAEA Fusion Energy Conference, Daejeon Korea, 11-16 October 2010

►To achieve the superconducting tokamak construction and operation experiences, and

►To develop high performance steady-state operation physics and technologies that are essential for ITER and fusion reactor development

Major radius, R0

Minor radius, a Elongation, kTriangularity, dPlasma volume

Bootstrap Current, fbs

PFC Materials

Plasma shape

Plasma current, IP

Toroidal field, B0

Pulse length

bN

Plasma fuel

Superconductor

Auxiliary heating /CD

Cryogenic

PARAMETERS

1.8 m

0.5 m

2.0

0.8

17.8 m3

> 0.7

C, CFC (W)

DN, SN

2.0 MA

3.5 T

300 s

5.0

H, D

Nb3Sn, NbTi

~ 28 MW

9 kW @4.5K

Designed

1.8 m

0.5 m

2.0

0.8

17.8 m3

-

C

DN

0.5 MA

3.6 T

7 s

> 1.0

H, D, He

Nb3Sn, NbTi

2.0 MW

5 kW @4.5 K

Achieved

KSTAR Parameters

•Black : achieved •Red : by 2010

4

Mission and Achievements

KSTAR Mission


(a)

5

Advanced

High b, fbs

Long-pulse op.

Advanced Tokamak

Shaping (2010)

H-mode (2011)

bN < 3(2012)

Current profile control (2012)

Wall stabilization (2012)

Transport barrier (2012)

Standard


CharacteristicTime (sec)

yearplasma performance (βn)

2015

10-3

10-2

10-1

100

101

102

103

104

PFC cooling, Wall inventory

Particle Confinement

Energy Confinement

Disruption, ELM

MHD

Current Diffusion

Erosion

KSTAR OperationWindow

6

Long Pulse Operation


NBI-180 keV

1 MW, 2 s

NBI-180 keV

1 MW, 2 s

PFC Baking & Cooling200 C

PFC Baking & Cooling200 C

Cryogenic helium supply4.5 K, 600 g/s

Cryogenic helium supply4.5 K, 600 g/s

vacuum pumpingvacuum pumpingECH

84 GHz / 110 GHz0.5 MW, 2 s

ECH84 GHz / 110 GHz

0.5 MW, 2 s

ICRH30 ~ 60 MHz1 MW, 300 s

ICRH30 ~ 60 MHz1 MW, 300 s

KSTAR Device for 2010 Campaign

7


1st campaign (2008) 2nd campaign (2009)

3rd campaign (2010) 8

KSTAR Device Evolution

Overview of



•Super-conducting Magnets• Heating & Current Drive• Active Plasma Control• Plasma-Wall Interaction


Date (D/M/Y)

Aug. 6

Aug. 19Temperature (K)

300

250

200

150

100

50

07/8/10 10/8/10 13/8/10 16/8/10 19/8/10

3rd cool-down (2010)1st cool-down (2008)

SC Magnet Cool-down

►1st & 2nd cool-down (2008 / 2009)• Cool-down (from 300 K to 4.5 K) : 21 days (1st ), 31 days (2nd) • All the joints have resistance less than 5 nano-ohm

►3rd cool-down (2010) :• ITER cryogenic system study using KSTAR HRS was conducted in early 2010.

• Cool-down (from 270 K to 4.5 K) : 14 days (from Aug. 6 to Aug. 19)• Total 4700 hours of magnet operation without quench

10

FTP/P6-05, 28


TF Magnet Operation

11

►The TF magnet system was charged up to 35 kA, producing 3.5 T at the center of the vacuum vessel. The coil temperature increment was less than 0.2 K leaving the margin more than 4 K.

►The measured maximum mechanical stress of the TF structure at 35kA was 152 MPa, which is lower than the operational criteria of 500 MPa and maximum radial displacement from the estimation is less than 0.4 mm.


PF Magnet Operation

12

►Each PF coil was ramped-up and ramped-down to Max. 10 kA with 1 kA/s, while the temperature increase was approximately 1.5 K .

►At the fast ramp rate (±6 kA, 10 kA/s ramp-up, 100 ms blip ) test for single coil, the temperature increase was 8.7 K mainly due to the AC losses of super-conductors / jackets and the insufficient conditioning to reduce the coupling loss. Conditioning to the full current and optimization of the He distribution circuits will be planned.

23rd IAEA Fusion Energy Conference, Daejeon Korea, 11-16 October 2010 13

Effect of Incoloy on Magnetic Configuration

-0.5 0 0.5

-20

-15

-10

-5

0

5

10

Z[m]

Bz[G

]

-0.5 0 0.5

-10

-8

-6

-4

-2

0

2

4

6

8

10

Z[m]

Br[G

]calculated without incoloy

calculated with incoloy

the measured : + charging

the measured : - charging

BTF=0.1T

BTF=2T

Bz scan by Hall ProbeMulti-spot at field null

Bz exist but Br is negligible

Bz

loop voltage analysis due to up/down asymmetry in

cryostat

0 0.02 0.04 0.06 0.08 0.1

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

time[s]

curre

nt[kA

]

I PF1I PF2I PF3I PF4I PF5I PF6I PF7I VV[100kA]

0 0.02 0.04 0.06 0.08 0.1

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

time[s]

loop v

oltag

e [V]

FL01FL12FL23FL34FL45

Dashed : the calculatedSolid : the measured

Up-down asymmetry!

► Static magnetic field error investigation :• Bz distortion was about 25 G but Br distortion was negligible.• FEM calculation results agreed with hall probe & e-beam detection.

► Dynamic magnetic field error investigation :• Vertical displacement of KSTAR plasma found in 2008/ 2009. • Up-down asymmetric shape of the cryostat structure could generate

asymmetric eddy current (ITER will have the same issues).

EX/5-1


► Bz deformation due to ferromagnetic incoloy effect is compensated in 2010 KSTAR start-up scenario.

1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2-70

-60

-50

-40

-30

-20

-10

0Radial Bz profile around current channel formation phase

R [m]

Bz

[G]

KSTAR shot #2068 in 2009KSTAR shot #3148 in 2010

Required Bz for Ip=8 kA

Required Bz for Ip=10 kA

Modified Bz slope prevents plasma inboard crashduring initial current channel formation phase.

Effect of Incoloy on Plasma Startup EXS/P2-12


Robust Discharges up to 500 kA

PF coil current waveforms for 500 kA discharge

First 500 kA discharge without tuning the plasma control precisely (red) compared to the controlled discharges (blue)


Perspective Toward Steady-State Operation

SC magnet system for steady-state :• Reliable operations of SC magnet & cryogenic facility for long pulse operation

• Magnetic material effects on magnetic configuration characterized

Divertor & PFC :• Active-cooling on PFC & divertor will be prepared for long pulse operation• Particle and flow control (fueling, wall conditioning, pumping)• Dust characterization as a ITER safety issue

Heating & Current drive optimization :• Simulation study with ASTRA, ONETWO, TSC/TRANSP predicts possible steady-state operation scenarios

• Long-pulse, non-inductive NBCD, LHCD, ECCD being installed

Advanced confinement by active plasma control:• Predictive simulations showed the possibilities of control of ELM, RWMand NTM by active means

• Extensive experimental program will be done for advanced confinementphysics using profile diagnostics, heating and current drive systems andIVCC

Overview of



• Super-conducting Magnets

•Heating & Current Drive• Active Plasma Control• Plasma-Wall Interaction


KSTAR Specification Role in 2010

NBI

14 MW, 300 s D0/H0- Two beam lines- Three ion sources per each

beam line- Positive based ion source at120 keV

-Ion heating & CD-H-mode in initial phase

1 MW D0- One beam lines- One ion source- Beam energy : max. 80 keV- Beam pulse : less than 2 s

ICRF30 – 60 MHz, 8 MW(source), 300 s-Sources: Four 2MW transmitter

-Ion & electron heating in high density-On- and off-axis CD-Wall cleaning by RF discharge between shot

Frequency : 30 MHzSource power : < 1 MWPulse : <5 sUse 2 straps in the antenna

LHCD 5 GHz, 2 MW(source), 300 s- 4 x 500 kW CW klystrons

-Electron heating-Off-axis CD for plasma current profile control-RS-mode

ECH/CD

84/110 GHz, 0.5 MW(source), 2 s-84 GHz, 0.5 MW gyrotron

170 GHz, 3 MW(source), 300 s- 3 x 1 MW CW gyrotrons

• 84 (or 110) GHz ECH Startup system-Assisted startup using pre-ionization

•170 GHz ECCD system-2nd harmonic heating & CD-NTM stabilization leading to high beta-Sawteeth mode control (heating around q=1 surface)

ECH-assisted start up with

110 (and 84) GHz, 0.5 MW (5 s)Gyrotron

KSTAR Heating and Current Drive Systems


►Successful pre-ionization with 2nd harmonic ECH• 2nd harmonic ECH pre-ionization : 1.5 T with 84 GHz and 2.0 T at 110 GHz• Low voltage for startup could be lowered to 2 V.• Pre-ionization scanned according to injection direction, gas pressure and

ECH power. Power threshold was about 250 kW. • 2nd harmonic ECH pre-ionization could be applicable to ITER startup.

19

#1949TF = 20.36 kA

R = 1.8 m

t=-6.8 ms

Black: 84 GHz in 2008 (#794)Blue: 110 GHz in 2009 (#1767)

Plasma current

ECH (not calibrated)

Electron density (line-integrated)

Neutral pressure

Loop voltage Dα

t=0 t=0

ECH pre-ionization for 84 GHz and 110 GHzECH-assisted startup

ECH-assisted Startup EXW/P2-05


► Time delay in 2nd harmonic ECH and low electron density of pre-ionization are potentially harmful for machine safety.

► Before the formation of current channel (i.e. good confinement), low electron density of pre-ionization state cannot effectively absorb ECH beam power.

20

ECH-assisted Startup

a) ECH power (kW)

b) Electron line density

c) Da emission (A.U.)

2.3x10-18 m-2

300 kW

90 ms delay

0.8x10-18 m-2

t=0 (PF blip timing)

KSTAR shot 3124

20

Arc by reflected ECH beam around t=-43 msArc by reflected ECH beam around t=-43 ms


► To prevent the damage due to ECH beam, KSTAR adopts Ohmic breakdown -ECH-assisted burn-through scenario.

► Background plasma produced by Ohmic breakdown of neutrals can effectively absorb ECH power without the reflection of ECH beam.

21

ECH-assisted Startup

21

d) ECH power (kW)

b) Electron line density

c) Da emission (A.U.)

a) Plasma current (A)

5.0x10-18 m-2

t=0 (PF blip timing)

250 kW

50 ms delay

KSTAR shot 3223

Current channel formation from background plasma

Current channel formation from background plasma


Beam-Line in the Main Experimental Hall

Ion Source Power Supplies

Fabrication and Installation of the 1st NBI (NBI-1)


Deuterium Beam Extraction

▶The achieved beam data and the waveforms of the 3-s beam extraction with the beam energy of 80 keV and the beam current of 27 A

FTP/P6-16


Divergence and Perveance Doppler Shifted Spectrum

Beam Divergence and Species Ratio

q D+ : D2+ : D3

+ = 74 % : 23 % : 3 %

(at 64 kV/19 A, 3 s, 1.13 μperv)


First Beam Injection

2.8 2.85 2.9 2.95 3 3.05 3.1 3.15 3.20

0.5

t [s]NB

pow

er

[MW

]

2.8 2.85 2.9 2.95 3 3.05 3.1 3.15 3.21.82

2.2

t [s]

Da [A

.U.]

2.8 2.85 2.9 2.95 3 3.05 3.1 3.15 3.20

500

t [s]

FC

count [#

]

1st NB test shot : 0.4 MW with 50 keV for 50 msec Shot No. : 3455

A test shot to find beam trajectory without PF blip and

ECH pre-ionization

A test shot to find beam trajectory without PF blip and

ECH pre-ionization

Beam Power

Neutron (Fission chamber)

Da


▶ Transmitter• Frequency: 30, 37, 45, 50, 60MHz• Anode V/I: 22.2 kV/ 122 A• Screen grid V/I: 980 V/ 2.4 A• Control grid V/I: -470 V/ 9.2 A• Input RF power: 86.2 kW• Efficiency of FPA: 64.7%• VSWR (Driver/FPA): 1.22• VSWR (FPA/Dummy load): 1.51• Ion pump current: 0.6 mA

2 MW ICRF System

26

IC Wall Cleaning Experiments In 2009

EXW/P7-11

ICRH Experiment Result In 2009 Campaign


Bay Em

polarizer

Power monitor

Gauge

Pump-out Tee

D1

Torus Hall

ECH

WG SW

38 m

14 m

6 m

Arc detector

Arc detector

Power monitor

170 GHz, 1 MW ECH/CD system (2011)

1 MW, CW, 170 GHz Gyrotron

Goals: → H-mode: requires ECH for NTM control→ Steady-state: definitely requires off-axis CD ® ECCD + LHCD

2011

2013

2015

Transmission Line§ Total length ~ 70 m§ 63.5 mm corrugated circular waveguide§ 8 Miter bends§ No diamond window§ Estimated transmission loss 20%

Dummy load

JAEA

Launcher (PPPL)

27

Output RF


5 GHz, 0.5 MW LHCD system (2011)► CW prototype Klystron ► LH launcher system

• The prototype of 5 GHz, 500 kW CW klystron for KSTAR, has been commissioned and tested using two dummy loads successfully.

• The 5 GHz, 1 MW un-cooled LH launcher for KSTAR LHCD is designed.• For the RF performance test of the LH launcher, a prototype of one-channel 4-way

splitter is under fabrication.

Component Spec. 2010 2011 2012 2013

Klystron 5 GHz, 500 kW, CW Commissioning Order (for 1 MW) Installation

Launcher Based on 4-waysplitter

DesignPrototype fabrication

Fabrication (for 1 MW, 2 s)

Transmission Line WR 187 w/g, 70 m, 760 torr SF6 gas

DesignOrder

Installation

Power Supply 2 MW thyristor typeInstallation (for 500 kW)

CommissioningChange to chopper type

Order (for 1 MW)Fabrication

Installation

Control system EPICS and PLC based remote control

InstallationCommissioning

28

► Future work


2008 2009 2010 2011 2012

ECH/CD

- 84 GHz 0.5 MW/0.4 s 0.5 MW/2 s 0.5 MW/2 s 0.5 MW/2 s 0.5 MW/2 s

- 110 GHz 0.5 MW/2 s 0.5 MW/2 s 0.5 MW/2 s

- 170 GHz 1 MW/10 s 1 MW/300 s

LHCD 0.5 MW/2 s 1 MW/2 s

ICRF 30MHz50kW/10s

45 MHz300 kW/10 s 1 MW/10 s 1 MW/10 s 2 MW/300 s

NBI 80 keV D01.0 MW/2 s

100 keV D02.5 MW/10 s

120 keV D05 MW/300 s

Total 0.5 MW < 1 MW 2 MW > 5 MW > 9 MW

29

H&CD System Upgrade


Predictive Simulation

0.0 0.2 0.4 0.6 0.8 1.00.0

0.5

1.0

1.5

2.0

jLH

jTOT

jNBjBS

Curre

nt D

ensi

ty (M

A/m

2 )

rtor

0 2 4 6 8 10 120.0

0.2

0.4

0.6

0.8

LHCD

NBCD

total NI

bootstrap

total

Ip, M

ATime, s

Predictive simulations have been performed to establish steady-state operations by optimising current drive schemes in KSTAR.

TSC/TRANSP (PPPL)

ONETWO (ORNL)

ASTRA (SNU/NFRI)

ITER-relevant steady state scenario• 0.8 MA, 1.95 T• fully non-inductive current drive with

a bootstrap current fraction above 0.6• βN above 3, H98(y,2) above 1.5

THS/P2-04


Perspective Toward Steady-State Operations








Overview of



• Super-conducting Magnets• Heating & Current Drive

•Active Plasma Control• Plasma-Wall Interaction


Parameters Descriptions

Coil radiusTop & Bottom IVCC : 2,120 mmUpper & Lower IVCC : 2,500 mm

Coil case 3 mm thickness of SS316LN

ConductorHalf hard copper32 mm × 15 mm with 7 mm dia. Hole

Turn insulation 1 mm thickness of Kapton/glass fiber/ epoxy

Section insulation 1 mm thickness of Glass fiber/ epoxy

Ground insulation 1 mm thickness of Glass fiber/ epoxy

Total cross-section 80 mm × 80 mm

Coil Case

Filler

Ground Insulation

Section Insulation

Turn InsulationConductor

Corner Roving Filler

Top IVCC

Upper IVCC

Lower IVCC

Bottom IVCC

In-Vessel Control Coil (IVCC) FTP/P6-09


Upper VerticalControl Coil

Upper Radial Control Coil

Top FEC/RWM

Middle FEC/RWM

Bottom FEC/RWM

Lower RadialControl Coil

Schematic Diagram

Lower VerticalControl Coil

Upper IVC

Top FEC/RWM

Upper IRC

Middle FEC/RWM

Lower IVC Lower IRC

Bottom FEC/RWM

Electrical Connection Scheme of IVCC


Upper IVCCUpper IVCC

Top IVCCTop IVCC

Lower IVCCLower IVCC

Bottom IVCC

Bottom IVCC

Inboard Limiter(w/o tiles)

Inboard Limiter(w/o tiles)

Inboard Divertor(w/o tiles)

Inboard Divertor(w/o tiles)

Central Divertor(w/o tiles)

Central Divertor(w/o tiles) In-Vessel

CryopumpIn-Vessel

Cryopump

Coolant Manifold for PFCs

Coolant Manifold for PFCs

IVCC under Installation


First Results of the IVCC

Vertical Stabilization By IVC

KSTAR #3408 @4.422


Plasma Shaping THS/P2-05


Passive Stabilizer

• Two toroidal- ring shaped plates, 9 mechanical bridges • Segmented into quadrants, each quadrant is connected to

each other through gap resistors (totally 1.2 mW in toroidal)• Total 32 sectors (16 x 2)• 12 vertical supports, 4 horizontal supports • Upper parts support lower parts with 9 mechanical bridges • Graphite tile (impurity < 10ppm)• Back plate : CuCrZr alloy, water cooled

Changing material

Increasing cuts

THS/P2-05


►X-ray Imaging Crystal Spectrometer· Ti & Te & toroidal rotation profile

39

Wavelength

Spatial information Det 1

Det 4

Det 3

Det 2

w z

3.9494 Å 3.9944 Å

►Charge Exchange Spectroscopy· Ti & toroidal rotation profiles · 17 ch (act 8ch & back. 8 ch)

► ECE radiometry· Frequency : 110 ~ 196 GHz· Sawtooth measurement from 2009

Plasma

HFS LFS

~10cm~15cm

30~90cm

►ECE Imaging· Simultaneous high & low field sides

· 384 ch (24 x 16) · operation at 2 T

Plasma Profile Measurements

►Thomson scattering· Channels : core 4 & edge 5 (design : 42 channels)· Nd : Yag Laser : 2J, 10 Hz (ITER Laser 5J, 100Hz in 2011)

EXS/10-1


Zoom lenses

Dual Antenna/Mixer

Arrays

Local Oscillators (BWO)

HFS LFS

Focus lenses

Cassette

► Commissioned on Oct. 8, 2010► Target Sawtooth: OH discharge w/ ~1% fluctuation► More information in Oral talk, EXC/10-1Ra (Park, H.)

Before crashm=1 mode

After crashFlattened Te

First KSTAR ECEI data

40

KSTAR ECE Imaging (ECEI) System Commissioning

40


Detector Head (AXUV16ELG)

Be filter : 50 um thickness

1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.60.215

0.22

0.225

0.23

0.235

0.24

0.245

0.25

1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.60.22

0.225

0.23

0.235

0.24

0.245

0.25

0.255

SXR37(V)

SXR40(V)

Time (s)

Ch 37: outside inversion radius

Ch 40: inside inversion radius

à Sawtooth inversion radius: 19 cm

1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8

100

200

300

400

500

600

700

800

900

1000

Time (s)

Freq

uenc

y (H

z)

-20

-18

-16

-14

-12

-10

-8

-6

-4

25 Hz of sawtoothoscillation

Oscillation frequency: 25Hz

Sawtooth inversion radius : ~19 cm

ch 37

ch 40

Installed SXR array

First result of SXR

41


▶Peak bN exceeds 0.6, peak stored energy exceeds 50 kJ, Ip reaches 335 kA▶Reconstruction includes evolution of vessel currents

(a)

2048

Plasma reconstructions of long pulse, high current plasmas

THS/P2-05


Ideal MHD Stability Analysis for KSTAR Target AT Mode

L-mode edge profile H-mode edge profile

▶ A detailed calculation with DCON, GATO for equilibrium including H-mode edge profile

▶ KSTAR target AT mode with βN > 5 possible with optimized profiles of p(r), q(r)

Overview of



• Super-conducting Magnets• Heating & Current Drive• Active Plasma Control

•Plasma-Wall Interaction


11

22

22

33

55

44

66

77

88

Inboard Limiter22 Divertor (DN, 20 s)33 Passive Stabilizer44 Poloidal Limiter

11 In-Vessel Control Coil66 NB Armor77 In-Vessel Cryo-pump88 Mechanical Brides for the Passive Stabilizer

55

In-Vessel Components


Wall conditioning

2009 2010

•Baking •Vacuum vessel at 130 oC (hot water)•PFC at 130 oC (conduction)

•Vacuum vessel at 130 oC•PFC at 200 oC (Hot N2 gas)

•Glow discharge

•GDC (H2 & He)•During cool-down, GDC at daytime•During experiments, GDC at night

• Optimum GDC duration was about 2 hrseach

• Outgassing rate recover after about 5 hrs

•GDC (H2 & He)•During cool-down, GDC at daytime

•During experiments, GDC in the morning if required

• ICWC

• ICWC (He)• ICWC between shot or lunch time

• ICWC study according to pressure & power scan

• H & D Isotope exchange was observed.

• ICWC (He)• ICWC in the morning or lunch time

•Boronization

•Carborane injected (50 g)

• Impurity in vacuum decreased and maintained for about 100 shots

• In-homogeneus deposition

•Carborane

• Injection at 4 place for the homogeneus coating

Wall Conditioning Process

47

EXD/P3-17


Campaign PFC surface( unit : ㎡) Baking system

1st 1.54 • Water baking system for VV ( 100 ℃)

2nd 11• Water baking system for VV ( 130 ℃)• Jacket heater baking system for duct ( 120 ℃)

3rd 54

• Water baking system for VV ( 130 ℃)• Jacket heater baking system for duct ( 120 ℃)• Hot gas baking system for PFCs ( 200 ℃)

KSTAR 1st Campaign

KSTAR 2nd Campaign

KSTAR 3rd Campaign

Effect of Baking

Total outgassing

2nd

Campaign3rd

Campaign

Total ( mbar·ℓ/s ) 2.13 ×10-4 6.49 ×10-4

Per unit area

( mbar·ℓ/s∙㎡)1.93 ×10-5 1.22 ×10-5

48


Vacuum Wall Condition

► During the baking, D2 and He GDC is performed in both campaigns.

► The water and oxygen levels in the vacuum vessel in the 3rd campaignare much lower than that after the 1st boronization in the 2nd campaign.

49


▶Inter-shot ICWC effectively removes H2O and suppresses the water level in the vacuum vessel.

▶With an overnight D2 GDC, the walls were saturated by ~1024 D atoms (similar to TS).

▶H retention rate of 1.2-3.8ⅹ1020

H/sec is measured with almost no sign of saturation in bulk.

▶H(D) removal rate of 0.17-6.11ⅹ1019 H(D)/sec.

▶Other impurity removal rate ~ 1016

-1017 molecules/sec.

Effects of ICWC and Particle Balance


Surface after Plasma-Dust Interaction

Lab

KSTAR

▶ Different surface/internal micro-structures are identified.▶ This is due to the crystallization and the plasma-dust interaction.▶ Micro-crystal structures have a size of about 1-2 um.▶ Micro-structures are broken into pieces which leads to smaller metal dusts.

Dust Researches in KSTAR

Surface Morphology

51

FTP/P1-32


-0.05 0.00 0.05 0.100

1

2

3

4

5

6

7

8

9

Hea

t flu

x on

div

erto

r (M

W/m

2 )

Distance from striking point (m)

12 MW 10 MW 8 MW 6 MW 4 MW

2 4 6 8 10 12 140123456789

10

q peak

on

dive

rtor (

MW

/m2 )

Input power (MW)

gsput=0.0 % gsput=0.1 % gsput=1.0 % gsput=3.0 %

▶Using B2 code, divertor heat fluxes calculated for various operation powers and C+ impurity condition for KSTAR divertor model

▶It is shown that C+ impurity changes the intensive radiation position from outer SOL near divertor to private region near X-point, reducing peak heat flux

Divertor Transport Simulation for KSTAR

Overview of


III. COLLABORATION


World Leading Experts(International)

55

Collaboration frame of KSTAR

World Class Institute (WCI) Program

WLEWCITh/Sim.

Diagnostic & SSO

(POSTECH)

Reactor Engineering

(SNU)

Plasma Heating(KAERI)

Edge Plasma(HYU)

Plasma Transport

(KAIST)

ITER Pilot R&DITER-IO Fusion

SimulationSciDAC (US), etc.

KSTAR Co-Exp.ITER Members

Non-ITER

International Collaboration

Matching Funds& Collaboration

WLE

WLE

WCIExp2

WCIExp1

Domestic Collaboration

Fusion R&D Collaboration


Physics issues in KSTAR boring plasma Nature of transport• characterization of non-local transport feature, like intermittent or avalanche• mechanism of cold-pulse propagation (edge cooling -> core heating)• new approach for transport analysis (analysis of local and non-local processes)

Edge transport (for pre-LH transition phase)• thorough measurement & analysis of edge turbulence characteristics• primary mechanism among various candidates, like ITG, RBM, DTE, ETG etc.• clarification of multi-component shearing (ZF, GAM) and dynamics (burst, pulsation)

Electron thermal transport• origin of LOC/neo-Alcator scaling (the model of DTEM is not sufficient?)• Te profile stiffness degree -> exponent and coefficient• nonlinear heat pinch

Particle/impurity transport• mechanism of improved particle confinement (IOC, RI/Z-mode, p-ITB etc.)• density profile stiffness degree• dominant particle pinch mechanism?• turbulent impurity transport

Momentum transport• dependences of intrinsic rotation on density, shape, SOL-flow etc. in Ohmic, L-mode • correlation of LOC->SOC with toroidal rotation direction change


Joint Experiments in 2010

• Vertical stability controls• Real-time EFIT & isoflux control

• MHD (ECEI, SXR, MC)• Fast filtered imaging diagnostic : TV

• ECH pre-ionization (fundamental) • ICRF heating : coupling / D / minority / fastwave• NB heating

• ECH discharge cleaning• hydrocarbon flux/energy by deposition probe

• Sawtooth• Runaway• TAE• Locked mode & tearing mode• Operation space : density limit

• L-H transition• Rotation properties• Radial transport of impurity• Low density Ohmic confinement

►55 proposals submitted

►Classified into 6 tasks• Plasma commissioning (7)• Diagnostics (9)• Heating and current drive (10)• Plasma wall interaction (7)• MHD (15)• Transport and confinement (7)

Domestic (41)

§ NFRI (22) § POSTECH (6)§ KAERI (11)§ SNU (2)

International (14)

§ GA (6)§ PPPL (2) § ORNL (1)§ Far-Tech (1)§ ANU (2)§ JAEA (2)


§ TC-2 Power ratio – Hysteresis and access to H-mode with H~1§ TC-3 Scaling of the Low-Density Limit of the H-mode threshold§ TC-9 Scaling of intrinsic plasma rotation with no external momentum input§ TC-14 RF rotation drive§ PEP-22 Controllability of pedestal and ELM characteristics by edge ECH/ECCD/LHCD§ PEP-28 Physics of H-mode access with different X-point height§ DSOL-8 ICRF conditioning§ DSOL-9 C injection experiments to understand C migration§ DSOL-13 Deuterium co-deposition with carbon in gaps of plasma facing components§ MDC-13 Vertical stability physics and performance limits in Tokamaks with highly elongated plasmas§ MDC-15 Disruption database development§ MDC-16 Runaway electron generation, confinement, and loss § IOS-2.1 ECRH breakdown assist at 20-degree toroidal angle§ IOS-2.2 Ramp-down from q95=3§ IOS-5.2 Maintaining ICRH coupling in expected ITER Regime.§ IOS-6.2 li controller (Ip ramp) with primary voltage / additional heating§ DIAG-3 Resolving the discrepancy between ECE and TS at high Te§ DIAG-4 Field test of a Capacitance diaphragm Gauge as a dust monitor for ITER

58

ITER High Priority Research Topics (IEA/ITPA)

Keywords of key issues :Shaping / H-mode / rotation / disruption ECRH breakdown / ICRF conditioning / runaway / dust

Overview of


IV. FUTURE PLAN


5-Year Operation Plan (Phase I)2012

‘12. 3 ~‘12. 8

• Profile control• ITER shape• ELM & disruption

• BT : 2 ~ 3.5 T• IP > 1 MA • tP ~ 20 s• Ti ~ 5 keV• Shape ~ DN & SN• Gas : D2

• TF : 35 kA [3.5 T] • PF : +/-20 kA (~8Wb)• IVCC : FEC,RMP,RWM• Grid: 100 MVA

+ Cryopump operation

• ECH(84/110G):0.5MW• ECCD(170G): 1MW• ICRH : 1.5MW • NBI : 5MW• LHCD : 0.3MW

+ MSE / MIR / BES / VUV / CX-NPA /etc

2011

‘11. 4 ~‘11. 9

• H-mode • MHD • Disruption• Wall interaction

• BT : 2 ~ 3.5 T• IP > 1 MA• tP > 10 s• Ti ~ 3 keV• Shape ~ DN & SN• Gas : D2

• TF : 35 kA [3.5 T] • PF : +/-15 kA (~6Wb)• IVCC : VS• Grid: 100 MVA

+ PFC cooling

• ECH(84/110G):0.5MW• ECCD(170G): 1MW• ICRH : 1.5MW • NBI: 2MW• LHCD: 0.3MW

+ FIR / Div. bolometer /X-ray pinhole / Coherence imaging/ fast-ion / etc

2010

‘10.6 ~‘10. 12

• Shape control• L-mode • MHD study• Wall conditioning

• BT : 2 ~ 3.5 T• IP > 0.5 MA• tP > 5 s• Ti ~ 1 keV• Shape ~ DN (κ2.0)• Gas : D2

• TF : 35 kA [3.5 T] • PF : +/-10 kA (~4 Wb)• IVCC : VS• Grid: 100 MVA

+ Divertor+ Passive stabilizer + In-vessel coil + PFC baking

• ECH(110G):0.5MW• ICRH: 1MW • NBI: 1MW

+ Thomson (5ch)/ ECEI / IRTV / Image Bolometer / CES / neutron / XICS-2 / Ellipsometry /

2009

‘09. 8 ~‘09.12

• Startup stabilization• ECH pre-ionization• ICRF wall

conditioning

• BT : 2 ~ 3.5 T• IP > 0.3 MA• tP > 2 s• Te ~ 1 keV• Shape ~ Circular• Gas : D2

• TF : 35 kA [3.5 T] • PF : +/-4 kA (~2 Wb)• Grid : 50 MVA

• Inboard limiter + Boronization+ ICRF DC

• ECH(110G):0.2MW, 2s• ICRH: 0.3MW, 1s

+ XICS / Soft X-ray / Hard X-ray/ Resistive Bolometer / Probe / Reflectometer

• e-beam

2008

‘08. 3 ~‘08. 8

• First plasma startup• 2nd Harmonic ECH

pre-ionization

• BT ~ 1.5 T• IP > 0.1 MA• tP > 0.1 s• Te ~ 0.3 keV• Shape ~ Circular• Gas : H2

• TF : 15 kA [1.5T)• PF : 4 kA (~1 Wb)• Grid : 50 MVA

• Inboard limiter (belt)• Gas puff• Glow DC

• ECH(84G):0.3MW, 0.4s

• Magnetic Diagnostics / MMWI / ECE / Ha / VS / filterscope / TV /

• Hall probe array

Campaign

Operation Time

Experimental goals

Operation Parameters

Magnetic Control

Vacuum Conditioning

Heating & Current Drive

Diagnostics

60


Operation Phase I2008 ~ 2012

• Superconducting tokamak operation

• First plasma & inductive current ramp (2 MA)

• Plasma shaping&heating(DN & SN, H-mode)

SC Tokamak operation

Operation Phase II2013 ~ 2017

• Steady-state operation & ITER pilot device roles (300 s+)

• Plasma heating & non-inductive current drive

• Instability control in H-mode and AT-mode

Long-pulse operation

Operation Phase III2018 ~ 2022

• Advanced scenario for DEMO beyond ITER

• High-beta and high bootstrap current scenario

• Extreme operation of the superconducting tokamak

High performance operation

Phase IV2023 ~

• DEMO Engineering

• DEMO simulator

• Reactor material test

DEMO test bed

KSTAR will be operated as an international collaboratory to exploit the key scientific and technological issues for the ITER and attractive fusion reactor.

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Long-term Operation Plan

► Divertor plasma (‘10)

► H-mode operation (‘11)

► Fast stabilization (‘12)

Second Campaign (‘09)

320kA3.6sec3.0Tesla

First Plasma (‘08)

133kA0.25sec1.5Tesla

Overview of


V. SUMMARY


SUMMARY

§Successful initial operation of KSTAR showed the capability of advanced and steady-state operation which are essential for ITER and future fusion reactors.

§ECH-assisted and Ohmic plasma discharges up to 500 kA for 7 seconds have been routinely achieved.

§Plasma shaping and heating studies with active control tools are being performed and H-mode will be tried out in 2010 campaign.

§Fifty-five joint plasma experiments with domestic and international collaborators are being conducted to achieve the targeted goals in 2010 campaign, which consists of the essential part of KSTAR research activities.


Presentations on KSTAR in FEC2010Presentation Author Title

FTP/P1-32 SH Hong On the spherical dusts in fusion devices

EXS/P2-09 SH Hahn Approaches on vertical stability and shape control in KSTAR

EXS/P2-12 J Kim Stable plasma startup in KSTAR under various discharge conditions

EXW/P2-05 M Joung ECH-assisted startup by the second harmonic EC waves in KSTAR

EXW/P2-09 C Ryu Observation and analysis of HF MHD activities during sawteeth in KSTAR

THS/P2-04 YS Na Real-time control of NTM in time-dependent simulation on KSTAR

THS/P2-05 YS Park KSTAR equilibrium operating space and projected stabilization at high beta

THW/P2-04 J Seol Modeling of ECH-assisted startup in a tokamak

EXD/P3-17 WC Kim Initial phase wall conditioning in KSTAR

THC/P3-03 KM Kim Effects of pellet ELM pacing on mitigation of ELM energy loss in KSTAR

THC/3,4 SS Kim, JM Kwon ITB & momentum transport simulation

EXS/P5-08 YM Jeon Equil. Reconstruction of KSTAR plasmas

EX/5-1 SW Yoon Effects of magnetic materials on in-vessel magnetic configuration in KSTAR

FTP/P6-05 HK Na Current operation status of KSTAR

FTP/P6-09 HL Yang Status and result of the KSTAR upgrade for 2010 campaign

FTP/P6-16 YS Bae Commissioning results of the KSTAR NBI system

FTP/P6-28 SH Park Thermo-hydraulic characteristics of KSTAR magnet system

EXW/P7-11 JG Kwak First results from ICRH experiments in KSTAR

EXS/10-1 H Park Comparative study of sawtooth physics and Alfven waves via 2D ECEI

Overview of KSTAR - IAEA NA · Overview of KSTAR Initial Experiments National Fusion Research...

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