Results of pellet injection into ISX-B

Conference · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5489460

Schuresko, D D

Improvements in plasma performance with pellet injection have been achieved in several tokamaks in recent experiments. On the Impurity Study Experiment (ISX-B), an increase in plasma energy by as much as 50%, has been observed following pellet injection. With 1.5-mm pellets, the value for tau/sub E/, the gross energy confinement time determined from ..beta../sub equil/, has peaked at 1.7 times ISX-B scaling for n/sub e/ = 6 x 10/sup 13/ cm/sup -3/ in both well-gettered and ungettered discharges. Following the peak, in the well-gettered shots tau/sub E/ decays to 1.2 times ISX-B scaling within 50 ms after pellet injection. In the ungettered discharges tau/sub E/ follows the Z-mode scaling that is appropriate to the plasma conditions (P/sub B/ = 1.7 MW, I/sub p/ = 180 kA). Thus, pellet injection in ISX-B shows energy confinement better than that for gas puffing in clean discharges and matches the Z-mode improvement obtained in ungettered discharges. Confinement improvement following pellet injection has also been acheived in smaller (a/sub p/ = 20 cm) plasmas with 1.0 mm diameter pellets. Comparisons of pellet shots which do show this improvement against pellet shots which do not show it was present.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5489460
• Report Number(s): CONF-8510266-6; ON: DE86014236
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
700205 -- Fusion Power Plant Technology-- Fuel
Heating
& Injection Systems
CONFINEMENT
CONFINEMENT TIME
GETTERING
ISX TOKAMAK
PELLET INJECTION
PLASMA CONFINEMENT
SCALING LAWS
THERMONUCLEAR REACTORS
TOKAMAK TYPE REACTORS