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 Engineering College 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 AINSE 1 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: 1992 Major radius1m Minor radius m Vacuum chamber33m 2 excellent access Aspect ratio5+ toroidal Magnetic Field  1 Tesla (0.2 DC) Heating Power0.2MW 28 GHz ECH 0.3MW 6-25MHz ICH Parameters: achieved to date :: expected n3e18 :: 1e19 T~100eV(T e ) :: 500eV(T e )  0.1 :: 0.5%

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 of transform (  ) magnetic well and shear 

Blackwell, Australian ITER Workshop, 10/2006 E-Beam mapping (wire tomography) Rotating wire array 64 Mo wires (200um) 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 PLCS Cooling, vacuum and sequence control Generator and heating power control H-1 Sequencer

Blackwell, Australian ITER Workshop, 10/2006 H-1 Remote data access MDSPlus IDL RFX JScope VNC

Blackwell, Australian ITER Workshop, 10/2006 H-1NF Data: MDSPlus + MySQL 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 Microwave Source: (Kyoto-NIFS-ANU collab.)  28 GHz gyrotron u 230 kW ~ 40ms ICRF Heating: B=0.5Tesla,  =  CH (f~7Mhz) Large variation in n e 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 5/45/4 4/34/3 7/57/5 5/45/4 4/34/3 7/57/5 gap D. Pretty, J. Harris

Blackwell, Australian ITER Workshop, 10/2006 Large Device Physics on H-1 Confinement Transitions, Turbulence (Shats, ) –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 tokamakH-1

Blackwell, Australian ITER Workshop, 10/2006 Magnetic fluctuations approach high temperature conditions: H, He, D; B ~ 0.5T; n e ~ 1e18; T e > 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, kHz, Alfvénic scaling with n e 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 n e 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 - n e : tomographic interferometer. (10kHz, ~2cm resol.) -T i,v i : “coherence imaging” optical system -  B ext : 2 x 20 coil “Mirnov” arrays  (m,n) up to 200 kHz -  B ext : CAE measurements, f< 5MHz OMAHA coils (UKAEA) -  B int : 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 – 2 C 20 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 – 2 C 20 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 – 2 C 20 coil combinations –100 shots ……. Cluster structures according to phase differences (m numbers)  reduces to 7-9 clusters for an iota scan Grouping 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=3,1 m=0, 3,5 m=3 m=2 m=0m=1 m=4 m=1,2, 3

Blackwell, Australian ITER Workshop, 10/2006 Diagnostic Collaborations e.g. Helium Diagnostic Beam Purpose – to locally measure T e and n e (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.