Blackwell, Australian ITER Workshop, 10/2006 H-1NF: the National Plasma Fusion Research Facility Boyd Blackwell* on behalf of the H-1 team* and the Australian

Blackwell, Australian ITER Workshop, 10/2006

H-1NF: the National Plasma Fusion Research Facility

Boyd Blackwell* on behalf of the H-1 team* and the Australian ITER forum

*Plasma Research Laboratory, Research School of Physical Science and EngineeringCollege of Science, Australian National University


H-1NF National Plasma Fusion Research Facility

A Major National Research Facility established in 1997 by the Commonwealth of Australia and the Australian National University

Mission:• Detailed understanding of the behaviour of magnetically confined hot plasma

in the HELIAC configuration• Development of advanced plasma measurement systems• Fundamental studies including turbulence and transport in plasma• Contribute to global research effort, maintain Australian presence in the field

of plasma fusion power

The facility is available to Australian researchers through the AINSE1 and internationally through collaboration with Plasma Research Laboratory, ANU.1) Australian Institute of Nuclear Science and Engineering

International collaboration played an important role in the success of H-1 in obtaining facility funding

Contract extended until 2010: limited operational funding


H-1 Heliac: Parameters

3 period heliac: 1992Major radius 1mMinor radius 0.1-0.2mVacuum chamber 33m2 excellent access

Aspect ratio 5+ toroidal

Magnetic Field 1 Tesla (0.2 DC)Heating Power 0.2MW 28 GHz ECH

0.3MW 6-25MHz ICH

Parameters: achieved to date::expected n 3e18 :: 1e19

T ~100eV(Te)::500eV(Te)

0.1 :: 0.5%



H-1 Vacuum Opening


H-1NF Photo


H-1 Configuration Map

• Original heliac: limited configuration range.

• “flexible heliac” : helical winding, with helicity matching the plasma, 2:1 range of iota

• H-1NF can control 2 out of 3 oftransform ()magnetic well andshear


E-Beam mapping (wire tomography)

Rotating wire array• 64 Mo wires (200um)

• 90 - 1440 angles

High accuracy (0.5mm)

Moderate image quality

Always available

Excellent agreement with computation

B.D.Blackwell, J. Harris, T.A. Santhosh Kumar, J.Howard


H-1 Remote control/Automatic scans

Four PLCSCooling, vacuum and sequence control

Generator and heating power control

H-1 Sequencer


H-1 Remote data access

MDSPlusIDLRFX JScope

VNC


H-1NF Data: MDSPlus + MySQL

Summary Database: one entry per shot - machine generated ~100 columnsId Shot iring Gas flow_2 rf_power p_iong ne_18 p_iong lenth Comment9001 45001 6500 He 0.0 59.1 1.1e-6 1.18 1.1e-6 .09 Test new MOSS camera9002 45002 6500 He 2.0 57.4 2.5e-6 1.51 1.2e-6 .091 Test new MOSS camera9003 45003 6600 H/He 0.5 59.4 1.1e-6 1.61 1.1e-6 .09 Test new MOSS camera9004 45004 6700 H/He 0.5 55.1 1.1e-6 1.63 1.1e-6 .09 Test new MOSS camera9005 45005 6800 H/He 0.5 61.7 1.2e-6 1.69 1.2e-6 .091 Test new MOSS camera….. ….

gas propertiesid name gauge fact flowfact1 hydrogen 2.2 2.92 helium 5.5 0.728 oxygen 0.99 8.018 argon 0.78 8.0

Log Entry Database: many entries per shot, 21 columnsId Shot topic precis Owner Comment script Comment5001 45001 datasys camac Disk full error5002 45001 impuriti

esNi impurity bdb112 Possible line at

4047plot_ccd_spectrum, sel-28

5003 45001 shotnote increase flow to 1.5 cam1125004 45001 MOSS modulation voltage

too lowcam112 need to modify

analysisfact=2.5 &anal_moss,foo,fact

need to modifyanalysis

5005 45002 shotnote He flow 2.0 cam112….. ….

topicsid topic description1 operations currents, timing2 RF RF heating3 ECH ECH system4 MHD equilibrium5 MOSS cameras, wheel6 probes LP, TMT,create table topics (id int unique auto_increment,topic enum('shotnote',

'unknown','operations','config','datasys','RF','ECH',

php web interface

mySQL database server

Graphic and textual queries

Machine and human generated data tables


ICRF and ECH Plasma

puff

ech

rf pre-ion.

diamagnetism

ne

Microwave Source:

(Kyoto-NIFS-ANU collab.)

28 GHz gyrotron

230 kW ~ 40ms

ICRF Heating:

•B=0.5Tesla, = CH

(f~7Mhz)

•Large variation in ne with iota

Backward Wave Oscillator Scanning Interferometer (Howard, Oliver)


Configuration scan: Magnetic Fluctuations

ICRF plasma configuration scan

Mode spectrum changes as resonances enter plasma

No simple explanation for “gap”

left side corresponds to zero shear at resonance

Gap not obvious in ECH 5/4 4/37/5

5/4 4/37/5

gap

D. Pretty, J. Harris


Large Device Physics on H-1

Confinement Transitions, Turbulence (Shats, 1996--)– H-mode 1996

– Zonal Flows 2001

– Spectral condensation of turbulence 2005

Magnetic Island Studies – H-1 has flexible, controlled and verified geometry

– Create islands in desired locations (shear, transform)

– Langmuir probes can map in detail

Alfvén Eigenmodes• (over)

D3D tokamak H-1Pinj (MW)

1

2

3

Edge ne (1019 m–3)10

Edge Te (keV)

0.1

0.2

0.3

1600 2000 2400 2800t (ms)

Edge Te (eV)

t (ms)

6

3

Prf (kW)

ne (r/a = 0.3) (1017 m–3)

80

40

0

030

20

10

20 40 60


Magnetic fluctuations

approach high temperature conditions: H, He, D; B ~ 0.5T;ne ~ 1e18; Te<50eV

i,e << a,

mfp >> conn

• spectrum in excess of 100kHz

• mode numbers not yet accurately resolved, but appear low: m ~ 1- 8, n > 0

b/B ~ 2e-5

• both broad-band and coherent/harmonic nature

• abrupt changes in spectrum for no apparent reason


Poloidal mode number measurements

“bean-shaped” 20 coil Mirnov array• Phase vs poloidal angle is not

simple– Magnetic coordinates– External to plasma

• Propagation effects• Large amplitude variation

Significant interpretation problem in advanced confinement configurations

Expected for m =2

phase

magnitude

coil number (poloidal angle )


Two possible GAEs ~20-25kHz

Identification with Alfvén Eigenmodes

• Coherent mode near iota = 1.4, 26-30kHz, Alfvénic scaling with ne

• m number resolved by bean array of Mirnov coils to be 2 or 3.

• Cylindrical theory predicts two possible GAEs at m=2, and m=3

• Scaling in ne and k|| (iota)• Many other examples of Alfvénic

scaling

phase


Planned : Exploration of EPM Physics

• Passive Alfvén eigenmodes: Synergistic theory/experiment study of wave drive, and effect on confinement.

• Experiment: Multiple sources of non-thermal particle populations: RF heating, ECH, molecular beam and gas puff.

•Active Excitation :

– Compressional Alfvén antenna ~ 100’s kW.

– Selective frequency tuning for electron or ions (4-26 MHz)

• Diagnosis. Essential for EPM studies. Some include

- ne : tomographic interferometer. (10kHz, ~2cm resol.)

-Ti,vi : “coherence imaging” optical system

- Bext : 2 x 20 coil “Mirnov” arrays (m,n) up to 200 kHz

- Bext : CAE measurements, f< 5MHz OMAHA coils (UKAEA)

- Bint : sensitive mm-wave homodyne polarimeter/interferometer.

200 kW, 28GHz gyrotron

(also with M. J. Hole, L. C. Appel)


“Data Mining” handles large quantities of data

• 4 Gigasamples of data – 128 times– 128 frequencies– 2C20 coil combinations– 100 shots

• Data mining allows sub sampling, exploring and rule extraction

• Initial work with “Weka” java and Gabor transforms for time freq analysis

Huge data sets are a common problem in complex geometries often associated with advanced confinement configurations

D. Pretty


Mode Decomposition by SVD and Clustering

D. Pretty


• Initial decomposition by SVD ~10-20 eigenvalues

• Remove low coherence and low amplitude• Then group eigenvalues by spectral

similarity into fluctuation structures• Reconstruct structures

to obtain phase difference at spectral maximum

• Cluster structures according to phase differences (m numbers)

reduces to 7-9 clusters for an iota scan


Mode Decomposition by SVD and Clustering

D. Pretty


…….• Cluster structures according to phase

differences (m numbers) reduces to 7-9 clusters for an iota scanGrouping by clustering potentially more

powerful than by mode number– Recognises mixtures of mode numbers

caused by toroidal effects etc– Does not depend critically on knowledge of

the correct magnetic theta coordinate

m=3,1m=0,3,5

m=3m=2

m=0m=1

m=4m=1,2,3


Diagnostic Collaborationse.g. Helium Diagnostic Beam

• Purpose – to locally measure Te and ne (Sasaki et al.)

• Very narrow (15mm) very brief (200us) burst of He

• Allows point localised measurements

Pulsed jet

Skimmer

The University

of Sydney

D. Andruczyk, S. Collis

J. Howard Thurs PM


Summary• Configurational effects demonstrated:

– particle confinement effects, magnetic fluctuation spectra– Poloidal mode numbers identification with Mirnov array, Toroidal

soon– Alfvénic modes observed– New campaign of surface mapping provides further insight into

configuration scan

– Data mining – unsupervised reduction into physically significant clusters

• New Diagnostics (J. Howard Thurs PM) • Possible Contributions to ITER Effort

– Better understanding of plasma phenomena• Confinement Transitions• Alfvén Eigenmodes• Magnetic Islands

– Test Bed for Advanced Diagnostic Development– H1 plasma is similar to reactor edge plasma


Future• New diagnostics

– LIF E-field measurements – Triple probe array (T3)– Soft X-ray arrays, one interchangeable foil (University of Canberra)

•Dynamics - modulation of n and T, gas puffing– possibility of high field confinement transitions with increased power

•Plasma Generation: RF and ECH: improve Te and pulse length– 200kW ECH, 250kW RF, improved discharge cleaning

•Progression to high temperature: e.g.– Turbulence/Flow studies via correlation spectroscopy, microwave

scattering– Radial force balance information via coherence imaging

spectroscopy– Extensive Configuration Studies

• three control windings iota, well and shear• higher power for stability studies approaching ~ 0.5%• interchange, ballooning modes.

Documents

Blackwell, Australian ITER Workshop, 10/2006 H-1NF: the National Plasma Fusion Research Facility Boyd Blackwell* on behalf of the H-1 team* and the Australian