The contribution of radio-frequency rectification to field-aligned losses of high-harmonic fast wave power to the divertor in the National Spherical Torus eXperiment

Perkins, R. J.; Hosea, J. C.; Jaworski, M. A.; Ahn, J. -W.; Diallo, A.; Bell, R. E.; Bertelli, N.; Gerhardt, S.; Gray, T. K.; Kramer, G. J.; LeBlanc, B. P.; McLean, A.; Phillips, C. K.; Podestà, M.; Roquemore, L.; Sabbagh, S.; Taylor, G.; Wilson, J. R.

doi:10.1063/1.4916034

Title: The contribution of radio-frequency rectification to field-aligned losses of high-harmonic fast wave power to the divertor in the National Spherical Torus eXperiment

Journal Article · Mon Apr 13 00:00:00 EDT 2015 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4916034· OSTI ID:1279419

Perkins, R. J. ^[1]; Hosea, J. C. ^[1]; Jaworski, M. A. ^[1]; Ahn, J. -W. ^[2]; Diallo, A. ^[1]; Bell, R. E. ^[1]; Bertelli, N. ^[1]; Gerhardt, S. ^[1]; Gray, T. K. ^[2]; Kramer, G. J. ^[1]; LeBlanc, B. P. ^[1]; McLean, A. ^[3]; Phillips, C. K. ^[1]; Podestà, M. ^[1]; Roquemore, L. ^[1]; Sabbagh, S. ^[4];

^[1];

^[1]

Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Columbia Univ., New York, NY (United States)

The National Spherical Torus eXperiment (NSTX) can exhibit a major loss of high-harmonic fast wave (HHFW) power along scrape-off layer (SOL) field lines passing in front of the antenna, resulting in bright and hot spirals on both the upper and lower divertor regions. One possible mechanism for this loss is RF sheaths forming at the divertors. We demonstrate that swept-voltage Langmuir probe characteristics for probes under the spiral are shifted relative to those not under the spiral in a manner consistent with RF rectification. We estimate both the magnitude of the RF voltage across the sheath and the sheath heat flux transmission coefficient in the presence of the RF field. Though the precise comparison between computed heat flux and infrared (IR) thermography cannot yet be made, the computed heat deposition compares favorably with the projections from IR camera measurements. The RF sheath losses are significant and contribute substantially to the total SOL losses of HHFW power to the divertor for the cases studied. Our work will guide future experimentation on NSTX-U, where a wide-angle IR camera and a dedicated set of coaxial Langmuir probes for measuring the RF sheath voltage directly will quantify the contribution of RF sheath rectification to the heat deposition from the SOL to the divertor.

View Accepted Manuscript (DOE)

View Accepted Manuscript (Publisher)

Cite

Export

Save

Research Organization:: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Organization:: USDOE Office of Science (SC)

Grant/Contract Number:: AC05-00OR22725; AC02-09CH11466

OSTI ID:: 1279419

Alternate ID(s):: OSTI ID: 1228291

Journal Information:: Physics of Plasmas, Vol. 22, Issue 4; ISSN 1070-664X

Publisher:: American Institute of Physics (AIP)Copyright Statement

Country of Publication:: United States

Language:: English

Citation Metrics:

Cited by: 11 works

Citation information provided by
Web of Science

References (38)

A description of the full-particle-orbit-following SPIRAL code for simulating fast-ion experiments in tokamaks Kramer, G. J.; Budny, R. V.; Bortolon, A. Plasma Physics and Controlled Fusion, Vol. 55, Issue 2 https://doi.org/10.1088/0741-3335/55/2/025013	journal	January 2013
Far field sheaths from waves in the ion cyclotron range of frequencies Myra, J. R.; D’Ippolito, D. A.; Bures, M. Physics of Plasmas, Vol. 1, Issue 9 https://doi.org/10.1063/1.870529	journal	September 1994
SPIRAL field mapping on NSTX for comparison to divertor RF heat deposition Hosea, J. C.; Perkins, R.; Jaworski, M. A. RADIOFREQUENCY POWER IN PLASMAS: Proceedings of the 20th Topical Conference, AIP Conference Proceedings https://doi.org/10.1063/1.4864535	conference	January 2014
Fast wave current drive in H mode plasmas on the DIII-D tokamak Petty, C. C.; Baity, F. W.; deGrassie, J. S. Nuclear Fusion, Vol. 39, Issue 10 https://doi.org/10.1088/0029-5515/39/10/305	journal	October 1999
Effects of toroidal rotation shear on toroidicity-induced Alfvén eigenmodes in the National Spherical Torus Experiment Podestà, M.; Bell, R. E.; Fredrickson, E. D. Physics of Plasmas, Vol. 17, Issue 12 https://doi.org/10.1063/1.3524288	journal	December 2010
Characterisation of local ICRF heat loads on the JET ILW Jacquet, P.; Marcotte, F.; Colas, L. Journal of Nuclear Materials, Vol. 438 https://doi.org/10.1016/j.jnucmat.2013.01.075	journal	July 2013
Suppression of energetic particle driven instabilities with HHFW heating Fredrickson, E. D.; Taylor, G.; Bertelli, N. Nuclear Fusion, Vol. 55, Issue 1 https://doi.org/10.1088/0029-5515/55/1/013012	journal	December 2014
Modeling far-field radio-frequency sheaths in Alcator C-Mod D'Ippolito, D. A.; Myra, J. R.; Ochoukov, R. Plasma Physics and Controlled Fusion, Vol. 55, Issue 8 https://doi.org/10.1088/0741-3335/55/8/085001	journal	May 2013
Plasma Sheath Formation by Radio-Frequency Fields Butler, H. S.; Kino, G. S. Physics of Fluids, Vol. 6, Issue 9 https://doi.org/10.1063/1.1706905	journal	January 1963
Characterization and performance of a field aligned ion cyclotron range of frequency antenna in Alcator C-Mod Wukitch, S. J.; Garrett, M. L.; Ochoukov, R. Physics of Plasmas, Vol. 20, Issue 5 https://doi.org/10.1063/1.4803882	journal	May 2013
Surface thermocouples for measurement of pulsed heat flux in the divertor of the Alcator C-Mod tokamak Brunner, D.; LaBombard, B. Review of Scientific Instruments, Vol. 83, Issue 3 https://doi.org/10.1063/1.3689770	journal	March 2012
High harmonic fast waves in high beta plasmas Ono, Masayuki Physics of Plasmas, Vol. 2, Issue 11 https://doi.org/10.1063/1.871030	journal	November 1995
Fast-wave power flow along SOL field lines in NSTX and the associated power deposition profile across the SOL in front of the antenna Perkins, R. J.; Ahn, J. -W.; Bell, R. E. Nuclear Fusion, Vol. 53, Issue 8 https://doi.org/10.1088/0029-5515/53/8/083025	journal	July 2013
High-Harmonic Fast-Wave Power Flow along Magnetic Field Lines in the Scrape-Off Layer of NSTX Perkins, R. J.; Hosea, J. C.; Kramer, G. J. Physical Review Letters, Vol. 109, Issue 4 https://doi.org/10.1103/PhysRevLett.109.045001	journal	July 2012
Edge rotation and temperature diagnostic on the National Spherical Torus Experiment Biewer, T. M.; Bell, R. E.; Feder, R. Review of Scientific Instruments, Vol. 75, Issue 3 https://doi.org/10.1063/1.1646740	journal	March 2004
Techniques for the measurement of disruption halo currents in the National Spherical Torus Experiment Gerhardt, S. P.; Fredrickson, E.; Guttadora, L. Review of Scientific Instruments, Vol. 82, Issue 10 https://doi.org/10.1063/1.3642618	journal	October 2011
High density Langmuir probe array for NSTX scrape-off layer measurements under lithiated divertor conditions Kallman, J.; Jaworski, M. A.; Kaita, R. Review of Scientific Instruments, Vol. 81, Issue 10 https://doi.org/10.1063/1.3494381	journal	October 2010
Theory of a Probe in a Strong Magnetic Field Sanmartin, Juan R. Physics of Fluids, Vol. 13, Issue 1 https://doi.org/10.1063/1.1692776	journal	January 1970
Assessment of compatibility of ICRF antenna operation with full W wall in ASDEX Upgrade Bobkov, Vl. V.; Braun, F.; Dux, R. Nuclear Fusion, Vol. 50, Issue 3 https://doi.org/10.1088/0029-5515/50/3/035004	journal	February 2010
High harmonic fast wave heating efficiency enhancement and current drive at longer wavelength on the National Spherical Torus Experiment Hosea, J.; Bell, R. E.; LeBlanc, B. P. Physics of Plasmas, Vol. 15, Issue 5 https://doi.org/10.1063/1.2837051	journal	May 2008
Profiles of fast ions that are accelerated by high harmonic fast waves in the National Spherical Torus Experiment Liu, D.; Heidbrink, W. W.; Podestà, M. Plasma Physics and Controlled Fusion, Vol. 52, Issue 2 https://doi.org/10.1088/0741-3335/52/2/025006	journal	January 2010
Biasing, acquisition, and interpretation of a dense Langmuir probe array in NSTX Jaworski, M. A.; Kallman, J.; Kaita, R. Review of Scientific Instruments, Vol. 81, Issue 10 https://doi.org/10.1063/1.3490025	journal	October 2010
Spectral effects on fast wave core heating and current drive Phillips, C. K.; Bell, R. E.; Berry, L. A. Nuclear Fusion, Vol. 49, Issue 7 https://doi.org/10.1088/0029-5515/49/7/075015	journal	June 2009
Estimated RF sheath power fluxes on ITER plasma facing components Colas, L.; Milanesio, D.; Faudot, E. Journal of Nuclear Materials, Vol. 390-391 https://doi.org/10.1016/j.jnucmat.2009.01.248	journal	June 2009
Infrared camera diagnostic for heat flux measurements on the National Spherical Torus Experiment Mastrovito, D.; Maingi, R.; Kugel, H. W. Review of Scientific Instruments, Vol. 74, Issue 12 https://doi.org/10.1063/1.1623625	journal	December 2003
Full wave simulations of fast wave heating losses in the scrape-off layer of NSTX and NSTX-U Bertelli, N.; Jaeger, E. F.; Hosea, J. C. Nuclear Fusion, Vol. 54, Issue 8 https://doi.org/10.1088/0029-5515/54/8/083004	journal	May 2014
Exploration of spherical torus physics in the NSTX device Ono, M.; Kaye, S. M.; Peng, Y. -K. M. Nuclear Fusion, Vol. 40, Issue 3Y https://doi.org/10.1088/0029-5515/40/3Y/316	journal	March 2000
Effect of a R.F, signal on the characteristic of a langmuir probe Boschi, A.; Magistrelli, F. Il Nuovo Cimento, Vol. 29, Issue 2 https://doi.org/10.1007/BF02750367	journal	July 1963
Divertor sheath power studies in DIII-D using fixed Langmuir probes and three-dimensional modeling of tile heat flows Donovan, D.; Nygren, R.; Buchenauer, D. Physica Scripta, Vol. T159 https://doi.org/10.1088/0031-8949/2014/T159/014064	journal	April 2014
Advanced ST plasma scenario simulations for NSTX Kessel, C. E.; Synakowski, E. J.; Bell, M. E. Nuclear Fusion, Vol. 45, Issue 8 https://doi.org/10.1088/0029-5515/45/8/007	journal	July 2005
RF sheath-enhanced beryllium sources at JET’s ICRH antennas Klepper, C. C.; Jacquet, P.; Bobkov, V. Journal of Nuclear Materials, Vol. 438 https://doi.org/10.1016/j.jnucmat.2013.01.124	journal	July 2013
Towards identifying the mechanisms underlying field-aligned edge-loss of HHFW power on NSTX Perkins, R. J.; Ahn, J-W.; Bell, R. E. RADIOFREQUENCY POWER IN PLASMAS: Proceedings of the 20th Topical Conference, AIP Conference Proceedings https://doi.org/10.1063/1.4864505	conference	January 2014
Advances in high-harmonic fast wave physics in the National Spherical Torus Experiment Taylor, G.; Bell, R. E.; Hosea, J. C. Physics of Plasmas, Vol. 17, Issue 5 https://doi.org/10.1063/1.3371956	journal	May 2010
ITER ion cyclotron system: Overview and plans Swain, D. W.; Goulding, R. H. Fusion Engineering and Design, Vol. 82, Issue 5-14 https://doi.org/10.1016/j.fusengdes.2007.05.056	journal	October 2007
Investigation of the fluxes to a surface at grazing angles of incidence in the tokamak boundary Matthews, G. F.; Fielding, S. J.; McCracken, G. M. Plasma Physics and Controlled Fusion, Vol. 32, Issue 14 https://doi.org/10.1088/0741-3335/32/14/004	journal	December 1990
Edge ion heating by launched high harmonic fast waves in the National Spherical Torus Experiment Biewer, T. M.; Bell, R. E.; Diem, S. J. Physics of Plasmas, Vol. 12, Issue 5 https://doi.org/10.1063/1.1871953	journal	May 2005
Recent Fast Wave Coupling and Heating Studies on NSTX, with Possible Implications for ITER Hosea, J. C.; Bell, R. E.; Feibush, E. RADIO FREQUENCY POWER IN PLASMAS: Proceedings of the 18th Topical Conference, AIP Conference Proceedings https://doi.org/10.1063/1.3273706	conference	January 2009
Notes on the Effect of Noise on Langmuir Probe Characteristics Garscadden, A.; Emeleus, K. G. Proceedings of the Physical Society, Vol. 79, Issue 3 https://doi.org/10.1088/0370-1328/79/3/311	journal	March 1962

Cited By (2)

Resonance in fast-wave amplitude in the periphery of cylindrical plasmas and application to edge losses of wave heating power in tokamaks Perkins, R. J.; Hosea, J. C.; Bertelli, N. Physics of Plasmas, Vol. 23, Issue 7 https://doi.org/10.1063/1.4954899	journal	July 2016
Resolving interactions between ion-cyclotron range of frequencies heating and the scrape-off layer plasma in EAST using divertor probes Perkins, R. J.; Hosea, J. C.; Taylor, G. Plasma Physics and Controlled Fusion, Vol. 61, Issue 4 https://doi.org/10.1088/1361-6587/aaf69c	journal	March 2019

Similar Records

The contribution of radio-frequency rectification to field-aligned losses of high-harmonic fast wave power to the divertor in the National Spherical Torus eXperiment

Journal Article · Wed Apr 15 00:00:00 EDT 2015 · Physics of Plasmas · OSTI ID:1279419

Hosea, J. C.; Jaworski, M. A.; Diallo, A.; +14 more

Predictions of VRF on a Langmuir Probe under the RF Heating Spiral on the Divertor Floor on NSTX-U

Conference · Tue Jul 01 00:00:00 EDT 2014 · OSTI ID:1279419

Hosea, J C; Perkins, R J; Jaworski, M A; +2 more

Towards identifying the mechanisms underlying field-aligned edge-loss of HHFW power on NSTX

Journal Article · Wed Feb 12 00:00:00 EST 2014 · AIP Conference Proceedings · OSTI ID:1279419

Perkins, R. J.; Bell, R. E.; Bertelli, N.; +18 more

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Title: The contribution of radio-frequency rectification to field-aligned losses of high-harmonic fast wave power to the divertor in the National Spherical Torus eXperiment

Citation Formats

References (38)

Cited By (2)

Similar Records

Related Subjects