Density fluctuations and confinement in the Nagoya Bumpy Torus (NBT-1M)

Journal Article · Mon Apr 01 04:00:00 EST 1991 · Physics of Fluids B; (USA)

DOI:https://doi.org/10.1063/1.859833· OSTI ID:5750340

Komori, A; Iguchi, H; Fujiwara, M; Shoji, T; Hosokawa, M; Kawai, Y; Ikegami, H ^[1]

---

1. Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga, Fukuoka 816, Japan (JP)

The stabilization of low-frequency density fluctuations is evidenced in the Nagoya Bumpy Torus (NBT-1M) ({ital Plasma} {ital Physics} {ital and} {ital Controlled} {ital Nuclear} {ital Fusion} {ital Research} (IAEA, Vienna, 1985), Vol. 2, p. 551) in the presence of microwave-heated hot-electron rings. Flute-type fluctuations, which are considered to be stabilized by the charge-uncovering effect of the rings, are found to cause large plasma losses, and to affect radial density profiles in the way that the lower fluctuation level yields the steeper density gradient. The particle confinement is, therefore, improved by the hot-electron rings to some extent, but is mainly determined by the plasma convection, which is expected from the discrepancy between density and potential profiles. It is also found that fluctuations in a toroidal plasma inside the ring grow when a weak negative ambipolar potential and a steep density gradient are formed, and are reduced to a low level when a deep potential well is achieved.

• OSTI ID: 5750340
• Journal Information: Physics of Fluids B; (USA), Journal Name: Physics of Fluids B; (USA) Vol. 3:4; ISSN 0899-8221; ISSN PFBPE
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
CONFINEMENT
CONVECTION
ELECTROMAGNETIC RADIATION
ELECTRON RINGS
ENERGY TRANSFER
FLUCTUATIONS
HEAT TRANSFER
HEATING
HOT PLASMA
INSTABILITY
MASS TRANSFER
MICROWAVE RADIATION
PLASMA
PLASMA CONFINEMENT
PLASMA DENSITY
PLASMA HEATING
PLASMA INSTABILITY
POTENTIALS
RADIATIONS
STABILITY
TORI
VARIATIONS