fom-institute for plasma physics rijnhuizen association euratom-fom tp-3.2: determine transport...

FOM-Institute for Plasma Physics RijnhuizenAssociation Euratom-FOM

TP-3.2: Determine transport dependence on Ti/Te ratio in L-mode plasma

Roger Jaspers For: S. Soldatov, A. Kraemer-Flecken (TEXTOR)X. Duan (HL-2A)V. Vershkov (T-10)

Association Euratom-FOM Trilateral Euregio Cluster

R. Jaspers - ITPA ORNL 2008 - TP3.223 April 2008 2

TP-3.2: Transport dependence on Ti/Te in L-mode

- Machines involved: T-10, TEXTOR, HL-2A- Aims:

1. Measure E vs ne at different heating methods (change of Ti/Te: range from 0.1-1.2)

2. a. Measure plasma rotation Vturb b. Measure ExB Vturb

- Status: - TEXTOR: experimental session performed in Feb. 2008

- T-10: Measurements in October-december 2008

- HL-2A: experiments planned for November 22-29, 2007(incl visit Hogeweij/Jaspers), but failure power generator



1.0 1.5 2.0 2.5 3.0

20

30

40

50

We

Wi

Wi , P

ECRH scan

PICRH

scan

We, W

i [kJ]

Ptot

[MW]

We , P

ECRH scan

not yet saturated

Paux [MW]

1.0 1.5 2.0 2.5 3.0

20

25

30

35

40

45

1.0 1.5 2.0 2.5 3.0

55

60

65

70

75

80

106222

106224106224106224106224

106224106224106224

106225106225

106225106225

106225106225106225

106226106226106226106226

106226106226106226

106217106217106217106217

106217106217

106218106218106218106218

106218106218

106219106219106219106219106219106219

106221106221106221106221106221106221

106222106222106222106222106223106223

106223

106222

106224

106224106224

106224

106224106224

106224

106225106225

106225106225

106225106225106225

106226106226

106226

106226106226106226

106226

106217

106217

106217106217

106217

106217

106218106218

106218106218

106218

106218

106219

106219

106219

106219

106219

106219

106221

106221106221

106221106221

106221

106222106222106222106222

106223106223

106223

Reference. NBI only ~1.2 MW

ECRH scan ICRH scan

Exper., fit 0.22*Ip*P-2/3

0.15*Ip*P-2/3 [Weynants, NF 1999]

E [

ms]

Ptot

[MW]

We+

Wi [

kJ]

TEXTOR. Ip=250 kA, Bt=2.5, NBI+ICRH, NBI+ECRH

saturated

The dependencies We(Paux), Wi(Paux) are sufficiently different for ECRH and ICRH scans.

The Wtot saturation at Paux>2MW. The L-mode scaling ~P-2/3 is fulfilled. 0.48<Ti(0)/Te(0)<0.85

Global confinement with ECRH and ICRH



bc

de

bc,de=0.025 radcd= 0.05 radbd,ce=0.075 radbe= 0.1 rad

rcutoff

5 horns are focused to the center of vacuum camera.The middle one is launching.

O-modef0=2637 GHz, HOPPINGnc=(0.841.70)·1013cm-3

The layout provides 4 probing areas and 4 distances in poloidal direction. Good bases for investigation of turbulence spatial-temporal properties. The confident measurements of turbulence velocity in any regime.

=5.75

Scheme of experiment.New Correlation Reflectometer



Turbulence rotation. (I=250 kA, Bt=2.5,<ne>=1.5-2)

• Spontaneous rotation is observed.

• ECRH – leads to speed up of

turb, – no dependency on PECRH. !

• ICRH. – Low P ICRH – not much

influence/decrease. – higher P ICRH –spin up in EDD.

• “Rigid body rotation” for L-mode plasmas for r<35 cm.

0 5 10 15 20 25 30 35 400

2

4

6

Reference

+ICRH200 kW400 kW1400 kW

+ECRH200 kW400 kW550 kW

pol

[cm]

[k

m/s

]EDD

15 20 25 30 35 408

10

12

14

16

Reference

+ECRH200 kW400 kW550 kW

[k

rad

/s]

pol

[cm]

+ICRH200 kW400 kW1400 kW

EDD

TEXTOR. Reflectometry. Velocity profiles.



TP 6.1 Spontaneous rotation: Ohmic

• For Ohmic plasmas (Bt=2.25T, 350 kA):– Perpendicular turbulence rotation ~ 12krad/s– Rigid body rotation

0.4 0.5 0.6 0.7 0.8 0.9 1.0-3.00

-2.00

-1.00

0.00

1.00

2.00 m=2

= 1.27 [rad/s]

TEXTOR. Reflectometry. Turbulence rotation.

"rigid body"rotation

[ 1

04 r

ad

/s]

r/a

Ohmic, Normal FieldsOhmic, Reversed FieldsNBI-Co (1.4MW)NBI-Counter (1.4MW)



TP 6.1 Spontaneous rotation: ICRH

Toroidal rotation (CXRS) changes dramatically in the COUNTER – current direction after ICRH is applied.

Reflectometry = - + B/B

because of Co-NBI switched

after ICRH application

Er<0 agrees with fast ions losses because of ICRH.

1.0 1.5 2.0 2.5 3.0 3.5 4.00.0

0.5

1.0

CO

rc=28.5cmr

c=28cm

rc=32cm

rc=32.5cm

rc=33.5cm

rc=27.5cm

[10

4 rad

/s]

Time [s]

TEXTOR. #101066. Bt=1.9T, I=200kA. Reflectometry (32 GHz).

co-NBI = 300 kW

ICRH1.0MW

EDD

1,0 1,5 2,0 2,5 3,0 3,5 4,0

-10

0

10

20

30

40

CO

R=1.71 m R=1.74 m R=1.81 m R=1.86 m R=1.92 m R=1.94 m R=1.99 m R=2.03 m

Time [s]

[1

04 ra

d/s]

TEXTOR. #101061. Bt=1.9T, I=200kA. Plasma toroidal rotation from CXRS

ICRH1.5MW

co-NBI = 300 kW

CO

UN

TE

R



Further Plans:

• TP 3.2: - finalize task:– Density (collisionality) scan– Turbulence characterisation

• TP 6.1: (TEXTOR) no dedicated experiments, but simply contribute to database



ECRH



ICRH

fom-institute for plasma physics rijnhuizen association euratom-fom tp-3.2: determine transport...

Documents