마스터 부제목 스타일 편집Wonho CHOE Fusion Plasma Transport Research Center (FPTRC)

Korea Advanced Institute of Science and Technology (KAIST)

February 18, 2014

Research Activities in KAIST-FPTRC

PPPL Visit

2SXR & VUV imaging diagnostics on KSTAR (as of now)

Soft X-ray array (SXRA) 2 arrays, 32 ch (64 ch) t = 2 μs, r = 5 cm Ar Ross filters (Cl & Ca K-edge): 2.8 – 4.0 keV Be filters (10, 50 μm: 0.5, 1.0 keV): 2 color

VUV spectroscopy 28 ch for imaging (5 - 20 nm), t = 13 ms 1 ch for survey (15 - 60 nm), t = 13 ms

2-D Tangential X-ray pinhole camera (TXPC) Duplex (2 color), 50x50 ch t = 0.1 ms, r = 2 cm

GEM detector for 2-D X-ray camera 12x12 pixels, 128 ch t = 1 ms, r = 2 - 6 cm 3 – 30 keV

Tomographic reconstruction codes developed Max. Entropy Method Phillips-Tikhonov Min. Fisher Information Cormack

3

edge

0.004

0.006

0.008

0.01

0.012

0.014

0.016

0.018

0.02

HD arrays (33-64)

HU arrays (1-32)

16 ch (32)

16 ch (32)

HU

HD

VD2

VU2

• 4 arrays, 256 ch• 2 cm, 2 μs

1 array, 60 ch

• 2 filters multi energy, neural network

• 1.3 cm, 2 μs

(1) SXR array diagnostic system

4 array, 256 channels

2013 20142 array, 64 ch

• Be filters (10, 50 mm)• Ar Ross filters (Ar trans-

port)• Bolometer (No filter)

S.H. Lee J. Jang

4

(2) Imaging VUV spectroscopy

2013 (5-20 nm, ~3 ms)2012 (15-60 nm, 13-40 ms)

0.004

0.006

0.008

0.01

0.012

0.014

0.016

0.018

0.02

ITER prototype on KSTAR (5 – 60 nm)

Vacuum extension

VUV spectrometer on the optical table

28 ch, imaging

In collaboration with ITER KO-DA (C.R. Seon)

1 ch, survey

He I : 53.70 nmHe II : 25.63, 30.37 nmO V : 15.61, 19.28, 21.50 nmO VI : 17.30, 18.40 nmC III : 38.62 nmC IV : 24.49, 38.41, 41.96 nmC V : 22.72, 24.87 nmFe XV : 28.42 nmFe XVI : 33.54, 36.08 nmW : 5-20 nm

Ar XIV 18.79 nmAr XV 22.11 nmAr XVI 35.39 nm

5

2.50 2.52 2.54 2.56 2.58 2.60 2.62 2.64 2.66 2.68 2.700

100

200

300

400

500

600 r/a = 0.10 r/a = 0.30

Time (s)

X-r

ay p

hoto

n co

unt (

A.U

.)

(a) (b)

Sawtooth crash in #7640

(3) ‘Tangential’ X-ray pinhole cameraIn collaboration with KAERI (M. Moon)

‘Duplex (2-color) Multi-Wire Proportional Counter (MWPC) detector

7640image-81.1s - 81.2s

10 20 30 40 50

5

10

15

20

25

30

35

40

45

50

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

7640image-81.2s - 81.3s

10 20 30 40 50

5

10

15

20

25

30

35

40

45

50

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

(a) (b)

Channel

Cha

nnel

Channel

Outboard Outboard

5 10 15 20 25 30 35 40 45 50

5

10

15

20

25

30

35

40

45

50 -20

-15

-10

-5

0

5

10(b) - (a)

5 10 15 20 25 30 35 40 45 50

5

10

15

20

25

30

35

40

45

50

6

TXPC, RT-EFIT

Major radius, R

Visible camera

Major radius, R

Vloop

Ip

Stored en-ergy

ECE

Da

Shot 7886

Consistent with RT-EFIT and visible camera Tangential reconstruction on-going

X-ray imaging of VDE

S. Jang et al., CAP 13, 819 (2013)

7

Pulse Height Analyzer mode

Te by TXPC (PHA mode)

0 1 2 3 4 5 6 7 8 9 100

1

2

3

Te (A

.U.)

Time (sec)

ECE_2 TXPC_11

40 60 80 100 120 140 160 180 200 220 240 260

0.81.01.21.41.61.82.02.22.42.62.83.0

1 s 2 s 3 s 4 s Linear Fit of 1 Linear Fit of 2 Linear Fit of 3 Linear Fit of 4

# of

pho

tons

(log

_sca

le)

Pulse height (A.U.)

8

(4) GEM detector for TXPC Front Back

128 ch in 12x12 cm2 Spatial & time resolution:

2-6 cm, 1 ms

In collaboration with ENEA (D. Pacella)

55Fe Source

Gas inGas out

Lan cable

HV cable

FPGA

Zoom in & out

GEM

[4] W. Bonivento et al., Nucl. Instr. and Meth. A, 491, 233 (2002)

X-position mov-able

GEM foils: 50 µm thick kapton foil, copper clad on each side

Triple-GEM geometry: 3/1/2/1 mm Front-end electronics: CARIOCA micro chips by

LNF and CERN [4]

Active area: 10 x 10 cm2

Channels: 12 x 12 pixels (each pixel has 0.8 x 0.8 cm2)

Temporal: 10 µs (up to 255 frames), 1 ms (60k frames)

Mixed gas (flow): 70% Ar, and 30% CO2 at 1 atm Movable system

(zoom in & out and horizontally movable)

9

Preliminary result of GEM detectorshot 9033

Zoom inshot 9034 shot 9035 shot 9056

Zoom in & out

10

Time (s)

Freq

uenc

y (k

Hz)

2.632 2.634 2.636 2.638 2.64 2.6420

20

40

60

80

100

Sawtooth crash in H-mode

m = 1 (f = 19 kHz) is shown by spectrogram. Maximum displacement from the initial posi-

tion: 0.13 m Maximum rotation speed: 10.7 km/s

Spectrogramm = 1f = 19 kHz

R (m)

Z (m

)

Time 2.642000 sec

1.6 1.65 1.7 1.75 1.8 1.85 1.9 1.95 2-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

Trajectory of the hot core

rtEFIT

11

2.632 2.634 2.636 2.638 2.64 2.642

0.6

0.8

1

SXR

007

(kW

/m2 )

2.632 2.634 2.636 2.638 2.64 2.6420

0.1

0.2

(m

)

2.632 2.634 2.636 2.638 2.64 2.6420

5

10

15

v (k

m/s)

Time (s)

Comparison between L- & H-mode

1.028 1.03 1.032 1.034 1.0360.2

0.3

SXR

007

(kW

/m2 )

1.028 1.03 1.032 1.034 1.0360

0.1

0.2

(m

)

1.028 1.03 1.032 1.034 1.0360

5

10

15

v (k

m/s)

Time (s)

Crash

< 5 km/s

0.1 m

Crash

< 10 km/s

< 0.1 m

L-mode, low vФ H-mode, high vФ

1.028 1.03 1.032 1.034 1.0360.2

0.3

SXR

007

(kW

/m2 )

1.028 1.03 1.032 1.034 1.0360

0.1

0.2

(m)

1.028 1.03 1.032 1.034 1.0360

5

10

15

v (km

/s)

Time (s)

2.632 2.634 2.636 2.638 2.64 2.642

0.6

0.8

1

SXR

007

(kW

/m2 )

2.632 2.634 2.636 2.638 2.64 2.6420

0.1

0.2

(m)

2.632 2.634 2.636 2.638 2.64 2.6420

5

10

15

v (km

/s)

Time (s)

Crash in multi steps

Crash in a single step

Displacement from central position

Displacement from central position

Poloidal velocity Poloidal velocity

12Correlation between SXR rotation speed & vФ (XICS)

50 100 150 200 2500

5

10

15

20

25

Toroidal Rotation Velocity [km s-1]

Freq

uenc

y (m

= 1

) [kH

z]

#7640#7642#7644#7645#7646#7647

• The m=1 SXR rotation speed is compared with toroidal rotation speed (XICS).• Toroidal rotation frequency

0 5 10 15 20 250

5

10

15

20

25

Rotation Frequency [kHz]

Freq

uenc

y (m

= 1

) [kH

z]

#7640#7642#7644#7645#7646#7647

Rf

2

13

ECH effect on Ar transport Argon gas injection through a piezo valve (nAr/ne < 0.1%)

Different transport with varying ECH positions Feasibility of impurity control? Analysis of Ar transport coefficients in L-mode (#7566, #7574) & H-mode (#7745, #7863)

by using UTC-SANCO code with diagnostic results (SXR, VUV, XICS)

0.4

0.2

0 1 2 3 4 Time (sec)

Ip (M

A)

Ar puffing20 ms

#756

6 0.4

0.2

0 1 2 3 4 Time (sec)

Ip (M

A)

Ar puffing20 ms

#757

4

ECH110 GHz350 kW

#786

3

L-mode

w/o ECH

R [m]

Z [m

]

1.2 1.4 1.6 1.8 2 2.2 2.4

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

Heating positions(r/a = 0, 0.16, 0.30, 0.59)

w/ ECH

40 cm20100

Ar puffing after ECH start

Ar

14

1.8 1.9 2 2.1 2.2 2.3-10

0

10

20

30

40

50

60

70

80

Time [s]

P SXR [W

m

-2]

No ECHOn-axis ECH = 0.16 = 0.30 = 0.59

Depending on ECH position

Time (s)

400

mm

20

0 m

m

100

mm

O

n-ax

is

No

ECH

Chor

d #

1.5 2 2.5 3 3.5

1

161

161

161

161

16

No ECH

On-axis ECH

ECH @r/a = 0.16

0.30

0.59

Less core accumulation of Ar impurity with ECHMost effective (i.e., least core impurity concentration) with on-axis ECHLess effective with resonance layer position at larger radius

No ECH

On-axis ECH

0.16

0.30

r/a = 0.59

L-mode

15

2-D Reconstructed Ar emissivity• Core-focused reconstruction (Cormack algorithm)• Emissivity images of mainly Ar16+ & Ar17+ impurities

No ECH On-axis ECH

1.4 1.6 1.8 2 2.20

0.1

0.2

0.3

R (m)

I SXR (k

W/m

3 )

0.04

0.06

0.08

P SXR (k

W/m

3 )

SXR004

0.1

0.15

0.2

P SXR (k

W/m

3 )

SXR007

0.1

0.15

0.2

P SXR (k

W/m

3 )

SXR010

0.01

0.02

0.03

0.04

0.05

P SXR (k

W/m

3 )

SXR019

2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3

0.1

0.15

0.2

0.25

Time (s)

P SXR (k

W/m

3 )

SXR024

Shot #7566, Time: 2.240000 s

1.4 1.6 1.8 2 2.20

0.1

0.2

R (m)

I SXR (

kW/m

3 )

0.04

0.06

0.08

0.1

P SXR (

kW/m

3 )

SXR004

0.1

0.15

0.2

0.25

P SXR (

kW/m

3 )

SXR007

0.1

0.15

0.2

0.25

P SXR (

kW/m

3 )

SXR010

0.02

0.04

0.06

P SXR (

kW/m

3 )

SXR019

2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 30.1

0.15

0.2

0.25

Time (s)

P SXR (

kW/m

3 )

SXR024

Shot #7574, Time: 2.194000 s

1.41.6

1.82

2.2

-0.5

0

0.5

0

0.05

0.1

0.15

0.2

0.25

R (m)Z (m)

PSX

R (k

W/m

3 )

1.41.6

1.82

2.2

-0.5

0

0.5

0

0.05

0.1

0.15

0.2

0.25

R (m)Z (m)

PSX

R (kW

/m3 )

16

• With ECH, central diffusion and convection are increased.• The pinch direction reverses at r/a < 0.3.

Modification of D & V by ECH

0 0.2 0.4 0.6 0.8 10.1

0.2

0.3

0.4

0.5

Diff

usio

n (m

2 /s)

r/a0 0.2 0.4 0.6 0.8 1

-15

-10

-5

0

Con

vect

ion

(m/s

)

r/a

0 0.2 0.4 0.6 0.8 10.1

0.2

0.3

0.4

0.5

Diff

usio

n (m

2 /s)

r/a0 0.2 0.4 0.6 0.8 1

-15

-10

-5

0

5

Con

vect

ion

(m/s

)

r/a

Non ECH (#7566)

On-axis ECH (#7574)

Outward Inward

Inward

17

0 0.2 0.4 0.6 0.8 10

0.5

1

1.5

2

2.5

3

3.5

4

4.5x 10

16

#/m

3

r/a

No ECH

Total ArAr+17

Ar+16

0 0.2 0.4 0.6 0.8 10

2

4

6

8

10

12

14

16x 10

15

#/m

3

r/a

On-axis ECH

Total ArAr+17

Ar+16

◈ Radial profile of total Ar density at peak time (2.3 s)

◈ Total Ar density

r/a

Tim

e (s

)

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.82.05

2.1

2.15

2.2

2.25

2.3

1

2

3

4x 1016

r/a

Tim

e (s

)

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.82.05

2.1

2.15

2.2

2.25

2.3

0

2

4

6

8

10

12

14

16x 10

15No ECH (#7566) On-axis ECH (#7574)

Total Ar Total Ar

Hollow Ar density profile by ECH

18

Neoclassical contribution of Ar transport

No ECH (#7566)

On-axis ECH (#7574)

0 0.1 0.2 0.3 0.4 0.50

0.1

0.2

0.3

0.4

0.5

Diff

usio

n (m

2 /s)

r/a

0 0.1 0.2 0.3 0.4 0.5-15

-10

-5

0

5

Con

vect

ion

(m/s

)

r/a

0 0.1 0.2 0.3 0.4 0.50

0.1

0.2

0.3

0.4

0.5

Diff

usio

n (m

2 /s)

r/a

0 0.1 0.2 0.3 0.4 0.5-10

-5

0

5

Con

vect

ion

(m/s

)r/a

0 0.1 0.2 0.3 0.4 0.5

7

8

9

10x 10

-3

Diff

usio

n (m

2 /s)

r/a

0 0.1 0.2 0.3 0.4 0.5-0.1

-0.05

0

0.05

0.1

0.15

Con

vect

ion

(m/s

)

r/a

Neoclassical calculation of D and V by NCLASS - The same input (Te, ne) of SANCO calculation - Ar16+ (dominant charge state) distribution at the peak time is used.

D, V calculated by NLCASS is smaller by an order of magnitude than the experimental D, V.

The impurity transport is anomalous, rather than neoclassical.

NCLASS

Exp

19Impurity pinch 3 impurity pinch terms[1] in Weiland multi-fluid model

Pinch type Description Pinch directionby turbulence type

Curvature pinch Compressibility of ExB drift v Inward

Thermodiffusion pinch Compression of the diamagnetic drift v ITG OutwardTEM Inward

Parallel impurity compression

Parallel compression of parallel v fluctuations produced along the field line by fluctuating

electrostatic potential

ITG InwardTEM Outward

GYRO and XGC simulations are on-going to find the dominant turbulence mode of No ECH and on-axis ECH cases.

It is expected that TEM is the dominant mode because of ECH effect on Te profile. It may be due to parallel impurity compression driven by increased R/LTe

[2]

[1] H. Nordman et al., 2011 Plasma Phys. Control. Fusion 53 105005 [2] C. Angioni et al.,2006 Phys. Rev. Lett. 96 095003

Curvature pinch

Thermodiffusion pinch

Parallel compression

pinch

20Diagnostics & analysis tools ready for W injection experiment

5 - 20 nm wavelength range is mainly used for measurement of W emission spectra. ASDEX-U: VUV (~5 nm) JET: VUV (~5 nm) & SXR JT-60U: VUV (6.23 nm) LHD: EUV (6.09, 6.23 & 12.7 nm) KSTAR

- VUV (5 – 60 nm): ITER prototype- SXR

Simulation & Atomic data: SANCO-ADAS

W test particle injector under preparation/consideration Particle gun (under preparation on KSTAR) Laser blow-off system (C-Mod) Particle dropper (NSTX) Pellet injection (LHD)

21

Presentations and discussionsDesign and tomography test of Soft X-ray Array diagnostics

on KSTAR (Seung Hun LEE)

Design and tomography test of Edge Multi energy Soft X-ray Array diagnostics on KSTAR (Juhyeok JANG)

Impurity transport analysis and preparation of W injection experiments (Joohwan HONG)

Development of a tungsten injection injector for high Z impurity study (Joohwan HONG)