Initial physics results from the National Spherical Torus Experiment

S. M. Kaye, M. G. Bell, R. E. Bell, J. Bialek, T. Bigelow, M. Bitter, P. Bonoli, D. Darrow, P. Efthimion, J. Ferron, E. Fredrickson, D. Gates, L. Grisham, J. Hosea, D. Johnson, R. Kaita, S. Kubota, H. Kugel, B. LeBlanc, R. MaingiJ. Manickam, T. K. Mau, R. J. Maqueda, E. Mazzucato, J. Menard, D. Mueller, B. Nelson, N. Nishino, M. Ono, F. Paoletti, S. Paul, Y. K.M. Peng, C. K. Phillips, R. Raman, P. Ryan, S. A. Sabbagh, M. Schaffer, C. H. Skinner, D. Stutman, D. Swain, E. Synakowski, Y. Takase, J. Wilgen, J. R. Wilson, W. Zhu, S. Zweben, A. Bers, M. Carter, B. Deng, C. Domier, E. Doyle, M. Finkenthal, K. Hill, T. Jarboe, S. Jardin, H. Ji, L. Lao, K. C. Lee, N. Luhmann, R. Majeski, S. Medley, H. Park, T. Peebles, R. I. Pinsker, G. Porter, A. Ram, M. Rensink, T. Rognlien, D. Stotler, B. Stratton, G. Taylor, W. Wampler, G. A. Wurden, X. Q. Xu, L. Zeng

Research output: Contribution to journalConference articlepeer-review

47 Scopus citations


The mission of the National Spherical Torus Experiment (NSTX) is to extend the understanding of toroidal physics to low aspect ratio (R/a ≃ 1.25) in low collisionality regimes. NSTX is designed to operate with up to 6 MW of high harmonic fast wave (HHFW) heating and current drive, 5 MW of neutral beam injection (NBI) and co-axial helicity injection (CHI) for noninductive startup. Initial experiments focused on establishing conditions that will allow NSTX to achieve its aims of simultaneous high βt and high-bootstrap current fraction, and to develop methods for noninductive operation, which will be necessary for Spherical Torus power plants. Ohmic discharges with plasma currents up to 1 MA and with a range of shapes and configurations were produced. Density limits in deuterium and helium reached 80% and 120% of the Greenwald limit, respectively. Significant electron heating was observed with up to 2.3 MW of HHFW. Up to 270 kA of toroidal current for up to 200 ms was produced noninductively using CHI. Initial NBI experiments were carried out with up to two beam sources (3.2 MW). Plasmas with stored energies of up to 140 kJ and βt = 21% were produced.

Original languageEnglish (US)
Pages (from-to)1977-1987
Number of pages11
JournalPhysics of Plasmas
Issue number5 II
StatePublished - May 2001
Event42nd Annual Meeting of the APS Division of Plasma Physics - Quebec, Que, Canada
Duration: Oct 23 2000Oct 27 2000

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics


Dive into the research topics of 'Initial physics results from the National Spherical Torus Experiment'. Together they form a unique fingerprint.

Cite this