Attainment of high confinement in neutral beam heated divertor discharges in the PDX tokamak

Technical Report · Tue Nov 01 00:00:00 EST 1983

DOI:https://doi.org/10.2172/5333542· OSTI ID:5333542

Kaye, S M; Bell, M; Bol, K; Boyd, D; Brau, K; Buchenauer, D; Budny, R; Cavallo, A; Couture, P; Crowley, T

The PDX divertor configuration has recently been converted from an open to a closed geometry to inhibit the return of neutral gas from the divertor region to the main chamber. Since then, operation in a regime with high energy confinement in neutral beam heated discharges (ASDEX H-mode) has been routine over a wide range of operating conditions. These H-mode discharges are characterized by a sudden drop in divertor density and H/sub ..cap alpha../ emission and a spontaneous rise in main chamber plasma density during neutral beam injection. The confinement time is found to scale nearly linearly with plasma current, but it can be degraded due to either the presence of edge instabilities or heavy gas puffing. Detailed Thomson scattering temperature profiles show high values of Te near the plasma edge (approx. 450 eV) with sharp radial gradients (approx. 400 eV/cm) near the separatrix. Density profiles are broad and also exhibit steep gradients close to the separatrix.

• Research Organization: Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
• DOE Contract Number: AC02-76CH03073
• OSTI ID: 5333542
• Report Number(s): PPPL-2056; ON: DE84004306
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
PDX DEVICES
PLASMA CONFINEMENT
NEUTRAL ATOM BEAM INJECTION
PLASMA DENSITY
POLOIDAL DIVERTORS
RECYCLING
THOMSON SCATTERING
BEAM INJECTION
CLOSED PLASMA DEVICES
CONFINEMENT
DIVERTORS
INELASTIC SCATTERING
SCATTERING
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
700101* - Fusion Energy- Plasma Research- Confinement
Heating
& Production