1. Results of NSTX heating experiments
- Author
-
Mueller, D., Ono, M., Bell, M.G., Bell, R.E., Bitter, M., Bourdelle, C., Darrow, D.S., Efthimion, P.C., Fredrickson, E.D., Gates, D.A., Goldston, R.J., Grisham, L.R., Hawryluk, R.J., Hill, K.W., Hosea, J.C., Jardin, S.C., Ji, H., Kaye, S.M., Kaita, R., Kugel, H.W., Johnson, D.W., LeBlanc, B.P., Majeski, R., Mazzucato, E., Medley, S.S., Menard, J.E., Park, H.K., Paul, S.F., Phillips, C.K., Redi, M.H., Rosenberg, A.L., Skinner, C.H., Soukhanovskii, V.A., Stratton, B., Synakowski, E.J., Taylor, G., Wilson, J.R., Zweben, S.J., Dorland, W.D., Peng, Y.K.M., Barry, R., Bigelow, T., Bush, C.E., Carter, M., Maingi, R., Menon, M., Ryan, P.M., Swain, D.W., Wilgen, J., Sabbagh, S.A., Paoletti, F., Bialek, J., Zhu, W., Raman, R., Jarboe, T.R., Nelson, B.A., Maqueda, R.J., Wurden, G.A., Pinsker, R.I., Schaffer, M., Ferron, J., Lao, L., Stutman, D., Finkenthal, M., Wampler, W., Kubota, S., Peebles, W.A., Gilmore, M., Mau, T.K., Lee, K.C., Domier, C.W., Deng, B.H., Johnson, M., Luhmann, N.C., Jr., Bonoli, P., Bers, A., Ram, A., Akers, R., Takase, Y., Ejiri, A., Ono, Y., Shiraiwa, S., Nishino, N., Mitarai, O., Nagata, M., Yang, J.G., Na, H., and Pacella, D.
- Subjects
Fusion reactors ,Business ,Chemistry ,Electronics ,Electronics and electrical industries - Abstract
The National Spherical Torus Experiment (NSTX) at Princeton University, Princeton, NJ, is designed to assess the potential of the low-aspect-ratio spherical torus concept for magnetic plasma confinement. The plasma has been heated by up to 7 MW of neutral beam injection (NBI) at an injection energy of 100 keV and up to 6 MW of high harmonic fast wave (HHFW) at 30 MHz. NSTX has achieved [[beta].sub.T] of 32%. A variety of MHD phenomena have been observed to limit [beta]. NSTX has now begun addressing [T.sub.E] scaling, [beta] limits, and current drive issues. During the NBI heating experiments, a broad [T.sub.i] profile with [T.sub.i] up to 2 keV, [T.sub.i] > [T.sub.e] and a large toroidal rotation were observed. Transport analysis suggests that the impurity ions have diffusivities approaching neoclassical. For L-Mode plasmas, [T.sub.E] is up to two times the ITER97L H-Mode scaling and exceeds the ITER98pby2 H-Mode scaling in some cases. Transitions to H-Mode have been observed which result in an approximate doubling of [T.sub.E] after the transition in some conditions. During HHFW heating, [T.sub.e] > [T.sub.i] and [T.sub.e] up to 3.5 keV were observed. Current drive has been studied using both coaxial helicity injection with up to 390 kA of toroidal current and HHFW. HHFW has produced H-modes with significant bootstrap current fraction at low [I.sub.p], high q, and high [[beta].sub.p]. Index Terms--Fusion reactors, plasma confinement, tokamaks.
- Published
- 2003