High poloidal beta equilibria in the Tokamak Fusion Test Reactor limited by a natural inboard poloidal field null*

Journal Article · Thu Aug 01 00:00:00 EDT 1991 · Physics of Fluids. B, Plasma Physics

DOI:https://doi.org/10.1063/1.859647· OSTI ID:5535431

Sabbagh, S. A. ^[1]; Gross, R. A. ^[1]; Mauel, M. E. ^[1]; Navratil, G.. A. ^[1]; Bell, M. G. ^[2]; Bell, R. ^[2]; Bitter, M. ^[2]; Bretz, N. L. ^[2]; Budny, R. V. ^[2]; Bush, C. E. ^[2]; Chance, M. S. ^[2]; Efthimion, P. C. ^[2]; Fredrickson, E. D. ^[2]; Hatcher, R. ^[2]; Hawryluk, R. J. ^[2]; Hirshman, S. P. ^[2]; Janos, A C ^[2]; Jardin, S. C. ^[2]; Jassby, D. L. ^[2]; Manickam, J. ^[2] ; McCune, D. C. ^[2]; McGuire, K. M. ^[2]; Medley, S. S. ^[2]; Mueller, D. ^[2]; Nagayama, Y. ^[2]; Owens, D. K. ^[2]; Okabayashi, M. ^[2]; Park, H. K. ^[2]; Ramsey, A. T. ^[2]; Stratton, B. C. ^[2]; Synakowski, E. J. ^[2]; Taylor, G. ^[2]; Wieland, R. M. ^[2]; Zarnstorff, M. C. ^[2]; Kesner, J. ^[3]; Marmar, E. S. ^[3]; Terry, J. L. ^[3]

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1. Columbia Univ., New York, NY (United States). Department of Applied Physics
2. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
3. MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States). Plasma Fusion Center

Recent operation of the Tokamak Fusion Test Reactor (TFTR) (Plasma Phys. Controlled Nucl. Fusion Research 1, 51 (1986)) has produced plasma equilibria with values of Λ≡β _{p eq}+ l _i/2 as large as 7, εβ _{p dia}≡ 2μ₀ε {l angle} p _⊥ {r angle}/{l angle}{l angle} B _p{r angle}{r angle}² as large as 1.6, and Troyon normalized diamagnetic beta (Plasma Phys. Controlled Fusion 26, 209 (1984); Phys. Lett. 110A, 29 (1985)), β _Ndia≡10⁸{l angle}β_t⊥{r angle} aB ₀/ I_p as large as 4.7. When εβ _{p dia}≳ 1.25, a separatrix entered the vacuum chamber, producing a naturally diverted discharge that was sustained for many energy confinement times, τ _E. The largest values of εβ _p and plasma stored energy were obtained when the plasma current was ramped down prior to neutral beam injection. The measured peak ion and electron temperatures were as large as 24 and 8.5 keV, respectively. Plasma stored energy in excess of 2.5 MJ and τ _E greater than 130 msec were obtained. Confinement times of greater than 3 times that expected from L-mode predictions have been achieved. The fusion power gain Q _DD reached a value of 1.3 x 10^₋3 in a discharge with I _p=1 MA and εβ _{p dia} = 0.85. A large, sustained negative loop voltage during the steady-state portion of the discharge indicates that a substantial noninductive component of I _p exists in these plasmas. Transport code analysis indicates that the bootstrap current constitutes up to 65% of I _p.

• Research Organization: Columbia Univ., New York, NY (United States). Department of Applied physics
• Sponsoring Organization: USDOE
• DOE Contract Number: FG02-89ER53297; AC02-76CH03073; FG02-90ER54084
• OSTI ID: 5535431
• Journal Information: Physics of Fluids. B, Plasma Physics, Vol. 3, Issue 8; ISSN 0899-8221
• Publisher: American Institute of Physics
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
HIGH-BETA PLASMA
EQUILIBRIUM
TFTR TOKAMAK
OPERATION
BALLOONING INSTABILITY
BOOTSTRAP CURRENT
ELECTRIC DISCHARGES
ELECTRON TEMPERATURE
ENERGY STORAGE
ION TEMPERATURE
PLASMA CONFINEMENT
PRESSURE GRADIENTS
STABILITY
STEADY-STATE CONDITIONS
VACUUM SYSTEMS
CONFINEMENT
CURRENTS
ELECTRIC CURRENTS
INSTABILITY
PLASMA
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
STORAGE
THERMONUCLEAR REACTORS
TOKAMAK TYPE REACTORS
700101* - Fusion Energy- Plasma Research- Confinement
Heating
& Production
700102 - Fusion Energy- Plasma Research- Diagnostics
700107 - Fusion Energy- Plasma Research- Instabilities