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
Blackwell, Australian ITER Workshop, 10/2006
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
Blackwell, Australian ITER Workshop, 10/2006
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%
Blackwell, Australian ITER Workshop, 10/2006
Blackwell, Australian ITER Workshop, 10/2006
H-1 Vacuum Opening
Blackwell, Australian ITER Workshop, 10/2006
H-1NF Photo
Blackwell, Australian ITER Workshop, 10/2006
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
Blackwell, Australian ITER Workshop, 10/2006
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
Blackwell, Australian ITER Workshop, 10/2006
H-1 Remote control/Automatic scans
Four PLCSCooling, vacuum and sequence control
Generator and heating power control
H-1 Sequencer
Blackwell, Australian ITER Workshop, 10/2006
H-1 Remote data access
MDSPlusIDLRFX JScope
VNC
Blackwell, Australian ITER Workshop, 10/2006
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
Blackwell, Australian ITER Workshop, 10/2006
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)
Blackwell, Australian ITER Workshop, 10/2006
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
Blackwell, Australian ITER Workshop, 10/2006
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
Blackwell, Australian ITER Workshop, 10/2006
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
Blackwell, Australian ITER Workshop, 10/2006
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 )
Blackwell, Australian ITER Workshop, 10/2006
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
Blackwell, Australian ITER Workshop, 10/2006
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)
Blackwell, Australian ITER Workshop, 10/2006
“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
Blackwell, Australian ITER Workshop, 10/2006
Mode Decomposition by SVD and Clustering
D. Pretty
• 4 Gigasamples of data – 128 times– 128 frequencies– 2C20 coil combinations– 100 shots
• 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
Blackwell, Australian ITER Workshop, 10/2006
Mode Decomposition by SVD and Clustering
D. Pretty
• 4 Gigasamples of data – 128 times– 128 frequencies– 2C20 coil combinations– 100 shots
…….• 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
Blackwell, Australian ITER Workshop, 10/2006
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
Blackwell, Australian ITER Workshop, 10/2006
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
Blackwell, Australian ITER Workshop, 10/2006
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.