Neutral beam injection experiments in ORMAK

Conference · Wed Jan 01 04:00:00 EST 1975

OSTI ID:4139536

Berry, L A; Bush, C E; Dunlap, J L; Edmonds, P H; Jernigan, T C; Lyon, J F; Murakami, M; Wing, W R

Two energetic (each approximately 26 kV, 100 kW) neutral beams were used to supplement the larger Ohmic heating of the Oak Ridge Tokamak (ORMAK) plasma. Long, constant discharge-current times and beam pulse lengths permitted an essentially equilibrium study of both plasma heating and other effects due to neutral beam injection. Both coinjection (beam parallel to the discharge current) and counterinjection (anti-parallel to the discharge current) were studied. Injection perturbs the plasma density and hence the electron-ion heat transfer, an effect which must be taken into account in evaluating the ion heating due to beam power input. The observed ion temperature increases with coinjection are in agreement with theoretical predictions both in magnitude ($delta$T/sub i//T/sub i/ ranging from 40 to 10 percent) and in scaling with plasma density. Measurements of parallel and perpendicular beam ion energy distributions are in agreement with theory, indicating little charge-exchange beam power loss, an effective ionic charge (Z) approximately 4, and significant beam energy transfer to the plasma. While net electron heating is sometimes observed with coinjection, the main effect of injection on electrons is to alter the radial distributions of electron temperature and density. Counterinjection was found to be much less effective than coinjection in plasma heating and to have a generally deleterious effect on the discharge parameters, stability, and confinement. (auth)

• Research Organization: Oak Ridge National Lab., TN
• NSA Number: NSA-33-005128
• OSTI ID: 4139536
• Country of Publication: IAEA
• Language: English

Related Subjects

*ORMAK DEVICES-- NEUTRAL ATOM BEAM INJECTION
700101* --Fusion Energy--Plasma Research--Plasma Confinement & Heating
CHARGE EXCHANGE
N70100* --Physics--Controlled Thermonuclear Research-- Confinement & Heating
PLASMA DENSITY
PLASMA HEATING
SCALING LAWS