K. Tanaka 1) , H. Takenaga 2) , K. Muraoka 3) , C. Michael 4) , L. N. Vyacheslavov 5) ,

Comparison study of particle transport and role of fluctuation in low collisionality regime in LHD and JT-60U

K. Tanaka1), H. Takenaga2), K. Muraoka3), C. Michael4), L. N. Vyacheslavov5),A. Mishchenko6), M. Yokoyama1), H. Yamada1), N. Oyama 2), H. Urano2), Y.

Kamada2), S. Murakami7),A. Wakasa8), T. Tokuzawa1), T. Akiyama1), K. Kawahata1),

M. Yoshinuma1), K. Ida 1),I. Yamada1), K. Narihara1), N. Tamura1)

1)National Institute for Fusion Science, Toki 509-5292, Japan2)Japan Atomic Energy Agency, 801-1 Mukouyama, Naka, Ibaraki 311-0193,

Japan3)Chubu University, 1200 Matsumoto, Kasugai, Aichi 487-8501, Japan

4) EURATOM/UAKEA Fusion Association, Oxfordshire OX14 3 DB, United Kingdom

5) Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia6) Max-Planck-Institute fur Plasmaphysik, EURATOM-Association, D-17491,

Greifswald, Germany7) Department of Nuclear Engineering, Kyoto University, Kyoto 606-8501,

Japan8) Graduate School of Engineering, Sapporo Hokkaido University, 060-8628,

Japan

Outline

1.General comparison of density profile in JT-60U and LHD

2.Density profiles and turbulence in JT-60U

3.Density profile and turbulence in LHD

4.Summary and Discussion(Possibility of curvature pinch)

Outline

1.General comparison of density profile in JT-60Uand LHD




The particularity of helical/stellarator is enhanced neoclassical transport in low collision regime

Neo

clas

sica

l Tra

nspo

rt

coeffi

cien

t

Banana

regime

ei

Plateau regime

1/ regime

Future operation regime of reactor

Around one order

Experimental De,e

Around one order

helical/stellaratortokamaktokamakFuture operation regime of reactor

Neo

clas

sica

l Tra

nspo

rt

coeffi

cien

t

Plateau regime

Experimental De,e

1/ regime

Plateau regime

ei

Magnetic axis position change magnetic helical ripple and higher ripple results in larger neoclassical transport

Position along Field Line

Mag

neti

c F

ield

+-

Helical ripple

Toroidal ripple

Trapped particle by the helical ripple

h_e

ff

t

Flux Surface

Orbit of guiding center

H C -I

Plasma

Helical coil

Shifts by external vertical field and Shafranov shifts

B contour

0

1

2

Rax

=3.5m

Rax

=3.6m

(c)

0

1

2

3

0 0.5 1

(d)

0

1

2

3

4

5

Low densityHigh Density

n e(1019

m-

3 )

(a)

0

1

2

3

4

5

0 0.5 1

Te(k

eV)

(b)

Density profile is Clear difference of density profiles were observed in JT-60U and LHD

JT60U Elmy H mode LHD

In both devices, the effect of particle fueling is small, the observed difference is due to the difference of particle transport

Both NBI heated plasma

0.8

1

1.2

1.4

1.6

1.8

10-1 100

LHD Rax=3.5mLHD Rax=3.6m

JT-60U Elmy H mode

b =0.5

n e(0.2

)/<

n e>Similar b

* dependence with tokamak at Rax=3.5m, opposite b

* dependence at Rax=3.6m were observed

Larger neoclassical

Larger anomalous

This is more important.

10-3

10-2

10-1

100

101

3.5 3.6 3.7 3.8 3.9

Experimental value Neoclassical value

Dco

re (=

0.4~

0.7)

(m

2 /sec

)

Rax (m)

Lines at Te core

=1.25keV

Neoclassical Minimum

Experimental Minimum

Anomalous contribution

Outline

1.General comparison of density profile in JT60-U and LHD




In tokamak, particle transport is dominated by anomalous one

Ware pinch is negligible in the present data set of JT-60U.

Linear Gyro kinetic theory (Angioni Nucl. Fusion 2004) and non linear gyro fluid theory (Garbet, P.R.L. 2003) predicts peaked density profile in ion dominant heating. These are caused by ion temperature gradient (ITG) mode.

In the dataset of JT-60U,i=Ln/Lt>1, this suggests ITG is lenaerly unstable.

Role of turbulence was experimentally studied by using correlation reflectometry.

Omode correlation reflectmetry was used to measure radial correlation for different peaked density profiles

Two frequency channelsOne is fixed at 47.3GHz (Cut off density (nc) 2.78x1019m-3)The other is scanned from 42.3 -46.8GHz (nc=2.23-2.73x1019m-3)Six frequencies were scanned in step. Each frequency was 20msec duration.

0

1

2

3

4

5

0 0.5 1

8.889-10.010s 12.131-13.002s

n e(1019

m-3

)

(a)Measurements region of reflectometer

f2

ne2

f3

ne3

f1

ne1

t

Freq.

120ms

0

0.5

1

-400 -200 0 200 400

coh 9.261seccoh 12.153sec

Coh

eren

ce a

t R

=10

mm

f(kHz)

Radial correlation was analyzed from correlation reflectometry

For quantitative estimation of radial correlation, coherence at R=20mm was used for parameter dependence.

0

0.5

1

0 50 100

8.889-10.010s12.131-13.002s

Coh

eren

ce

R(mm)

0.18

0.53

R=20mm

1. Representative values were averaged one for -200 - -100kHz.

2. Error was standard deviation for this frequency regime

3. 2~5 scans were accumulated for constant Ne and PNB duration.Accumulated

1.7

1.8

1.9

2

2.1

0.3 0.4 0.5 0.6 0.70.80.9 1

n e(0.2

)/<

n e>

eff

(=0.5)

Data used for analysis

Density peaking factor increased with decrease of collisionality as reported previously

de

eieff

ITG induce density peaking for eff<1

0.4

0.5

0.6

0.7

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Ln(m

)=-(

1/n

dn/d

r)-1

(m

)

Coherence at R=20.0mm

(a)

0.2

0.3

0.4

0.5

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Lt(m

)=-(

1/T

dT

/dr)

-1 (

m)


(b)

0

1

2

3

4

5

0 0.5 1

8.889-10.010s 12.131-13.002s

n e(1019

m-3

)


0

1

2

3

4

5

6

0 0.5 1

Te(k

eV)

(b)

Ln decreased with coherence. Coherence was higher for more peaked profile. Lt does not show any systematic trend with coherence

Ln and Lt was estimated from two YAG points (-0.15 and 0.5) indicated by arrow.

Peaked

Longer correlation

Longer correlation

1.75

1.8

1.85

1.9

1.95

2

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

y = 1.7447 + 0.33005x R= 0.6206

n e(0.2

)/<

n e>

coh at R=20.0mm

1.75

1.8

1.85

1.9

1.95

2

0 0.1 0.2 0.3 0.4 0.5

y = 1.968 - 0.3227x R= 0.48687

n e(0.2

)/<

n e>

eff

at cut off layer (-0.35)

Radial correlation shows clearer dependence on density peaking factor more than collisionality

V

D

n

nL

e

en

VnnD ee

Density peaking Smaller Ln

Larger radial coherence

Larger radial diffusion

Particle flux is given by

For steady state

Enhancement of inward pinch

Outline

1.General comparison of density profile in JT-60U and in LHD




These differences are not due to particle fueling but due to transport These differences are not due to particle fueling but due to transport characteristics.characteristics.

0

1

2

3

0 0.5 1

8.5MW 2.7MW 1MW

Te(k

eV)

0

1

2

0 0.5 1

n e(x10

19m

- 3 )

1011

1012

1013

1014

Par

ticl

e So

urce

Rat

e (A

.U.)

Density profile of LHD changes from peaked to hollow.

PNBI=

Change of density profile in N-NBI heated plasma at Rax=3.6m

Last closed flux surface

Last closed flux surface

Magnetic axis position changes density profile as well.

Inward shiftedSmall magnetic helical ripple and reduced neoclassical transport

Outward shiftedLarge magnetic helical ripple and enhanced neoclassical transport

0

1

2

3Rax=3.50m, Bt=2.83T Rax=3.75m, Bt=2.64m

0 0.5 1

Te(k

eV)

0

1

2

0 0.5 1

n e(x10

19m

- 3 )

Density modulation experiments shows Dcore is anomalous, outward Vcore is comparable with neoclassical one (K.Tanaka FUSION SCIENCE AND TECHNOLOGY VOL. 51 JAN. 2007 97)

Dcore

Dedge

0.7

Vcore

Vedge0.7

1.0

10-3

10-2

10-1

100

101

0.1 1 10

h_core

Dco

re(m

2 /sec

)

Neo.

Exp.

This difference can be driven by turbulence

-1

0

1

2

3

0.1 1 10

h_core

Vco

re a

t =

0.7

(m/s

ec)

Inward

Outard

Exp. Neo.

Dn

eo

*h

1* h

Plateau1/

2

3

1

21_

e

e

e

r

e

eneoe T

T

D

D

T

eE

n

nnD

2

3

1

21_

e

e

e

rneoe T

T

D

D

T

eEDV

Vneo is dominated by thermo diffusion.

20

With increase of PNB, density pump out and increase of core turbulence were observed.

1MW 6MW

VExB

VExB

Ne Ne

TeTe

0.01

0.1

1

10

0.01 0.1 1

n e2 at

ky

s

s=1.77mm

Noise Level

=0.6

T.H. Watanabe, H.Sugama Non linear GKV simulationi=3Nucl. Fusion 47 (2007) 1383–1390

Comparison between non linear GKV simulation and PCI measurement shows rough agreement.

kyi-0.3 kys-0.4

Preliminary

Measurement by 2 dimensional phase contrast imaging (2D-PCI)Te/Ti-2, so, kyi-0.3

Further confirmation is necessary.

=0-0.7

Outline

1.General comparison of density profile in JT-60U and in LHD




General formulation ( both for tokamak and stellarator/heliotron) of curvature pinch was developed (A.

Mishchenko et al, POP 14,102308 (2007)

The calculation is based on Isichenko’s model (M,B, Isichenko et al., Pjys. Plasma 3,1916 (1995))

It was assumed that the anomalous pinch is only curvature pinch and profile is in the steady state.

For large aspect ratio (r/R<<1) approximation, canonical density profile is given by

For larger aspect ration, curvature pinch becomes smaller. Sign of lnq (positive for tokamak, negative for stellarator/heliotron ) change the profile peaked or hollow.

Only trapped electron was taken into account (b>>)

0

1

2

3

4

5

0 0.2 0.4 0.6 0.8 1

ne (

x10

19m

-3)

0.5

0.6

0.7

0.8

0.9

1

1.1

0 0.2 0.4 0.6 0.8 1n e Nor

ma

lize

d P

rofil

e (

A.U

.)

Comparison between JT60-U density profile and curvature pinch model (data set of density scan)

Both exp. and model profile are peaked for higher density

The modeled curvature pinch is not large enough to account for observed profile.

high density, low density Exp. Model

0

0.5

1

1.5

2

2.5

0 0.2 0.4 0.6 0.8 1 1.2

ne(x

101

9 m-

3 )

0.8

0.9

1

1.1

1.2

0 0.2 0.4 0.6 0.8 1n e Nor

mal

ized

Pro

file

(A.U

.)

Comparison between LHD density profile and curvature pinch model (data set of scan)

=0.11%, =1.0%

Both exp. and model profiles are more peaked for lower .

Curvature pinch is not large enough. Neoclassical effect may be necessary.

Exp. Model

Density Peaking factor *dependence

Particle diffusion

Turbulence behavior

JT-60U Increase with a decrease of b*

Anomalous Radial correlation increases with increase of density peaking

LHD Increase with a decrease of b*at Rax=3.5m, increase with a increase of b* at Rax=3.6m

Anomalous, but neoclassical contribution increases with a decrease of b*.

Fluctuation power increase with decrease of density peaking

Summary I

Direction of particle convection

Origin of particle convection

Thermo diffusion

Curvature pinch

JT-60U Inward Anomalous ? Induce inward but not strong enough for observation

LHD Inward at Rax=3.5m. increase outward with a decrease of b* at Rax=3.6m

Neoclassical at hollowed profile, anomalous at peaked profile

Strong and induces outward due to neoclassical effect

Induce outward but not strong enough for observation

Summary II

28

t=4.0secBefore pump outNeo classical ambipola condition

predict weak positive Er field in core (<0.5) before and after density pumping out. If this is correct, phase velocity increases to i-dia direction in plasma frame. This is against GLF23 prediction in tokamak.

1. Are there different role between tokamak and helical plasma?

2. Are there different propagation direction between linear and non linear status?

3. Does larger contribution of neoclassical cause different role of turbulence?

4. Plasma poloidal rotation should be measured.

t=4.5secAfter pump out

1. Different collisionality dependence of density peaking was observed in JT-60U and LHD.

2. At Rax=3.5m with larger anomalous contribution, collisionality dependence of density peaking is similar to tokamak one (peaking factor increases with decrease of collisionality).

3. At Rax=3.6m with smaller anomalous contribution, collisionality dependence was opposite to Rax=3.5m and JT-60U.

4. With increase of NB power, density profile becomes more peaked in JT-60U.5. Radial correlation becomes higher for more peaked density profile6. With increase of PNB, density profile become hollow in Rax=3.6m of LHD.7. Peak wavenumber did not change with low and high PNB. This suggests correlation

length did not change.8. Fluctuation power increased with increase of PNB.9. Both in JT-60U and LHD, fluctuation characteristics changed for different density

profiles.10. In JT-60U, fluctuation may induce both diffusion and convection. 11. In LHD, fluctuation may induce diffusion, convection may be due to neoclassical

process.

Summary

Additional considerations are necessary.

1. Qualitative tendencies were agreed both in JT-60U and LHDi) Peaked profile for positive lnq in JT-60U and hollow profile for negative lnq.ii) JT-60U; more peaked profile in smaller density (lower collisionality) iii) LHD; more hollow profile in higher beta

2. In both case, curvature pinch is not strong enough.

3. Is situation really stationary?

4.Anomalous thermo diffusion should be considered in JT-60U5.Neoclassical thermo diffusion should be considered I LHD.

kcB

kkD

kql ,

),(

,

2

ebe

e

Tk

e

n

n

~

Larger fluctuation power induce larger diffusion according to quasi linear theory

Density flattening

Larger Ln

Larger fluctuation power

Larger radial diffusion

Smaller V(V is reversed. This may casused by neoclassical process

V

D

n

nL

e

en

nVd

dnDanom

ˆˆ

aBdjDD 2/3

08

1)(ˆ <>a is averaged for

trapped electron

aBBdjDV ln

82

3)(ˆ 2/3

0

d

D

Vnncan 0 )(ˆ

)(ˆexp)0()(

kc

B

kkD

k

,),(

,

2

0

Shape of density profile does not require saturated level of fluctuation.

D0 is canceled out.

What can we measure from correlation reflectometer?

1. The interpretation of the reflectometer signal is not simple.

2. The change of signal power does not represent fluctuation power (may indicate change of fluctuation power in some stage but sensitive to density gradient and curvature of the magnetic surface).

3. In the present system, we looked correlation of the signal assuming signal correlation represent correlation of fluctuation.

1.75

1.8

1.85

1.9

1.95

2

0.4 0.45 0.5 0.55 0.6 0.65 0.7

y = 2.6679 - 1.4115x R= 0.8184

n e(0.2

)/<

n e>

-Ln Yag(m) (=0.15-0.5)

1.75

1.8

1.85

1.9

1.95

2

0.4 0.5 0.6 0.7 0.8 0.9

y = 2.0681 - 0.30591x R= 0.71473

n e(0.2

)/<

n e>

eff

at

1.75

1.8

1.85

1.9

1.95

2

0 0.1 0.2 0.3 0.4 0.5

y = 1.968 - 0.3227x R= 0.48687

n e(0.2

)/<

n e>

eff

at cut off layer (-0.35)

Density peaking factor increases with decrease of Ln. Cleaer tred is seen between peaking factor and eff(0.5) more than between peaking facotr

and eff(0.35)

In both tokamak and helical/stellarator, turbulence driven transport is important for density profiles.

Therefore, it is essential to investigate characteristics of turbulence for different density profiles. from the measurements.

Comparison study between turbulence and density profiles will give a god guidance for numerical simulation.

The particularity of helical/stellarator is enhanced neoclassical transport in low collision regime

Neo

clas

sica

l Tra

nspo

rt

coeffi

cien

t

Banana

regime

ei

Plateau regime

1/ regime

Future operation regime of reactor

Around one order

Experimental De,e

Around one order

helical/stellaratortokamaktokamakFuture operation regime of reactor

Neo

clas

sica

l Tra

nspo

rt

coeffi

cien

t

Plateau regime

Experimental De,e

S. Murakami Nucl. Fusion 42 (2002) L19–L22

Axis Position Axis Position

Dne

o/D

toka

mak

pla

teu

Dne

o/D

toka

mak

pla

teu1/

regimePlateau regime

In 1/, neoclassical transport is minimum at Rax=3.53m

In Plateau, neoclassical transport is smaller at more inward axis.

Inward shifted

Outward shifted

Inward shifted

Outward shifted

ei

Role of neoclassical transport in tokamak and heliotron/stellarator in low collisionality regime

1. In tokamak , neoclassical effect (Ware pinch) is negligible in low collsionality regime

2. In LHD, diffusion is anomalous but convection is comparable with neoclassical thermo-diffusion in certain configuration.

( K.Tanaka 2007 Fusion Sci. Tech. , K.Tanaka 2008 Plasma Fusion Research )

0.4

0.5

0.6

0.7

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Ln(m

)


(a)

0.4

0.5

0.6

0.7

0.8

0.9

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

eff a

t cut

off

laye

r


More systematic trend was observed between Ln and coherence more than eff and coherence

Radial coherence might be more essential parameter for density peaking more than eff.

Core fluctuation may play role on density profile shaping.Most of fluctuation components exists in ITG/TEM unstable region

Tokamak like. Turbulence transport produce peaked profile

Helical particular. Inward turbulence driven flux can be balanced with outward neoclassical

Propagation direction tells local field angle. Local field angle tells local position.

Decomposed by FFT and MEM

Measured by 2D detector

Strong magnetic shear helps as well.

Shear techniques was done by Truc on Tore Supra (RSI (1992)) and Kado on Heliotron E (JJAP (1996))

toroidal

10-3

10-2

10-1

100

101

3.5 3.6 3.7 3.8 3.9


Dco

re (=

0.4~

0.7)

(m

2 /sec

)

Rax (m)

(a)Lines at Te core

=1.25keV



-2

-1

0

1

2

3

4

3.5 3.6 3.7 3.8 3.9

Vco

re (=

0.7)

(m

/sec

)

Rax (m)

(c)Lines at Te core

=1.25keV


Out

war

dIn

war

d

ExperimentalMinimum

Rax=3.5m →Peaked density profile Rax=3.6m→Peaked ~ hollow density profileRax>3,75m→hollow density profile

Anomalous contribution becomes larger

K. Tanaka et al., Journal of Plasma Fusion and Research 2008

Minimum Rax is different between experimental (~anomalous) and neoclassical diffusion coefficient→It is a contrast to energy confinement eff 1/∝ e is minimum at neoclassical minimum.

Vexp is comparable with Vneo. Both are minimum at Rax=3.5m

10-3

10-2

10-1

100

0.2 0.4 0.60.81 3

Dcore_exp

(=0.4~0.7)

Dcore_neo

(=0.4~0.7)

Dedge_exp

(=0.7~1.0)

Dedge_neo

(=0.7~1.0)

D (

m2 /s

ec)

Te(keV)

Rax=3.5m, Bt=2.83T

core exp. =1.8

core neo.=3.4

edge exp. =2.3

edge neo.=3.6

(a)

10-3

10-2

10-1

100

0.2 0.4 0.60.81 3

D (

m2 /s

ec)

Te(keV)

core exp. =1.4

core neo.=2.9

edge exp. =1.0

edge neo.=2.9

Rax=3.6m, Bt=2.75, 2.8T

(b)

Dcore

Dedge

0.7

Rax=3.5m →Peaked density profile→stronger Te dependence of D Rax=3.6m→Peaked ~ hollow density profile→weaker Te dependence of D

-1.5

-1

-0.5

0

0.5

1

1.5

0.6 0.8 1 2 3

Vexp

Rax=3.5m, Bt=2.83T

Vneo

Rax=3.5m, Bt=2.83T

Vexp

Rax=3.6m, Bt=2.75, 2.8T

Vneo

Rax=3.6m, Bt=2.75,2.8T

V a

t =

0.7

(m/s

ec)

Te (=0.4~0.7) (keV)

Out

war

dIn

war

d

V

v

Vcore

Rax=3.5m →Peaked density profile→negative Te dependence of Vcore Rax=3.6m→Peaked ~ hollow density profile→positive Te dependence of Vcore

10-3

10-2

10-1

100

101

3.5 3.6 3.7 3.8 3.9


Dco

re (=

0.4~

0.7)

(m

2 /sec

)

Rax (m)

(a)Lines at Te core

=1.25keV



-2

-1

0

1

2

3

4

3.5 3.6 3.7 3.8 3.9

Vco

re (=

0.7)

(m

/sec

)

Rax (m)

(c)Lines at Te core

=1.25keV


Out

war

dIn

war

d

ExperimentalMinimum

In LHD, anomalous and neoclassical contribution depends on magnetic configuration. The biggest configuration effect is magnetic ripple.

Inward-> Smaller ripple, Outward -> larger ripple

Diffusion; Anomalous contribution is larger at more inward shifted configuration.Convection; More or less comparable with neoclassical, but direction becomes inward against neoclassical prediction at more inward shifted configuration.

Rax=3.6m was compared with JT-60U data

0.6

0.8

1

1.2

1.4

1.6

10-1 100 101 102

Rax=3.5m, Bt=2.83TRax=3.6m, Bt=2.75,2.8TRax=3.75m, Bt=2.64TRax=3.9m,Bt=2.54T

h

* at =0.5

n e(0.2

)/(n

e>

Peaked profile

Hollow

profile

Dn

eo

*h

1* h

Plateau

1/

Larger neoclassical

Smaller neoclassical

At more outwardly Rax, neoclassical transport becomes larger and density profile becomes more hollow.

1. Different collisionality dependence of density peaking was observed in JT-60U and LHD.

2. At Rax=3.5m with larger anomalous contribution, collisionality dependence of density peaking is similar to tokamak one (peaking factor increases with decrease of collisionality).

3. At Rax=3.6m with smaller anomalous contribution, collisionality dependence was opposite to Rax=3.5m and JT-60U.

4. With increase of NB power, density profile becomes more peaked in JT-60U.5. Radial correlation becomes higher for more peaked density profile6. With increase of PNB, density profile become hollow in Rax=3.6m of LHD.7. Peak wavenumber did not change with low and high PNB. This suggests correlation

length did not change.8. Fluctuation power increased with increase of PNB.9. Both in JT-60U and LHD, fluctuation characteristics changed for different density

profiles.10. In JT-60U, fluctuation may induce both diffusion and convection. 11. In LHD, fluctuation may induce diffusion, convection may be due to neoclassical

process.

Summary

Density profiles were scanned from scan of NB power

Change of power spectrum suggest the change of fluctuation property.

0.4

0.5

0.6

0.7

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Ln(m

)


(a)

0.2

0.3

0.4

0.5

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Lt(m

)


(b)

0

1

2

3

4

5

0 0.5 1

8.889-10.010s 12.131-13.002s

n e(1019

m-3

)


0

1

2

3

4

5

6

0 0.5 1

Te(k

eV)

(b)

Ln decreased with coherence. Coherence was higher for more peaked profile. Lt does not show any systematic trend with coherence

Ln and Lt was estimated from two YAG points (-0.15 and 0.5) indicated by arrow.

0

5000

1 104

1.5 104

2 104

8000 90001 1041.1 1041.2 1041.3 104

498374983849845

4984849849

PNBI

TIME(ms)

2 1015

3 1015

4 1015

5 1015

6 1015

7 1015

8000 9000 1 1041.1 1041.2 1041.3 104

NELCU2

TIME(ms)

Ne scan for constant power1.49837 profile time 12.501s2.49838 profile time 12.566s3.49845 profile time 10.781s4.49848 profile time 10.297s5.49849 profile time 9.2826.49849 profile time, 12.399s

Power scan for constant Ne case11.49838 profile time 9.45s2.49848 profile time 9.556s3.49849 profile time 9.282s

Power scan for constant Ne case21.49838 profile time 12.566s2.49848 profile time 12.422s3.49849 profile time 12.399 s

Ne scan and Power scan

0

5000

1 104

1.5 104

2 104

8000 90001 1041.1 1041.2 1041.3 104

PNBI49837PNBI 49838PNB 49845PNBI 49848PNBI 49849

PNBI

TIME(ms)

2 1015

3 1015

4 1015

5 1015

6 1015

7 1015

8000 9000 1 1041.1 1041.2 1041.3 104

NELCU2 49837NELCU2 49838NELCU2 49845NELCU2 49848NELCU2 49849

NELCU2

TIME(ms)

14 cases for constant density (0.5~1s) and PNB from 5 discharges were used fro analysis.

Both profile and coherence was accumulated for each cases.

0.4

0.5

0.6

0.7

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Whole data Ne scan fo constant PowerPower scan for constant Ne

Ln(m

)

Averaged coh R=20.0mm

0.4

0.5

0.6

0.7

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Power scan for constant Ne, case1

Power scan for constant Ne, case2

Ln(m

)


0.4

0.5

0.6

0.7

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Ne scan fo constant Power

Ln(m

)


Ne scan and Power scan

It is difficult to say systematic trend for Power scan for constant Ne because of limited number of data

1.75

1.8

1.85

1.9

1.95

2

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

y = 1.7447 + 0.33005x R= 0.6206

n e(0.2

)/<

n e>

coh at R=20.0mm

The density peaking factor increases with increase of radial coherence

Density modulation experiments shows Dcore is anomalous, outward Vcore is comparable with neoclassical one (K.Tanaka FUSION SCIENCE AND TECHNOLOGY VOL. 51 JAN. 2007 97)

Blank; Experiment, Colored; Neoclassical

10-3

10-2

10-1

100

101

0.1 1 10

h_core

Dco

re(m

2 /sec

)

Neo.

Exp.

Rax=3.6n, Bt=2.75, 2.8T

Rax=3.6n, Bt=1.49T

Rax=3.75n, Bt=1.5T

Rax=3.9n, Bt=1.54T

-1

0

1

2

3

0.1 1 10

h_core

Vco

re a

t =

0.7

(m/s

ec)

Inward

Outard

Dcore

Dedge

0.7

Vcore

Vedge0.7

1.0

10-3

10-2

10-1

100

101

0.1 1 10

h_core

Dco

re(m

2 /sec

)

Neo.

Exp.

This difference can be driven by turbulence

-1

0

1

2

3

0.1 1 10

h_core

Vco

re a

t =

0.7

(m/s

ec)

Inward

Outard

Exp. Neo.

At lower collisionality Dcore is close toDneo.

Dn

eo

*h

1* h

Inward Vcore is not neoclassical.

Plateau1/

K. Tanaka 1) , H. Takenaga 2) , K. Muraoka 3) , C. Michael 4) , L. N. Vyacheslavov 5) ,

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Transcript of K. Tanaka 1) , H. Takenaga 2) , K. Muraoka 3) , C. Michael 4) , L. N. Vyacheslavov 5) ,