Microstability of the sloshing ions in TMX-U

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5463695

Berzins, L V

The microstability of the sloshing ions in the Tandem Mirror Experiment-Upgrade (TMX-U) was measured. This is the first experimental measurement of the microstability of a sloshing-ion distribution. It was found that the sloshing ions were unstable to the drift-cyclotron loss-cone instability. This instability was driven at the outer turning point of the sloshing ions. Experimental observations are compared with theoretical predictions for the drift-cyclotron loss-cone instability. It was on the basis of these comparisons that this instability was identified as the drift-cyclotron loss-cone instability. This instability affected the lifetime of the sloshing ions. The author compared the observed scaling of the sloshing-ion lifetime with the amplitude of the instability to the results of a quasi-linear theory where ion trapping is important. He shows that this instability can be stabilized by two different cold-ion populations in TMX-U. He observed warm-plasma stabilization of the instability by the cold-ion end losses. The amount of stream necessary to stabilize the instability is consistent with the theory for the drift cyclotron loss-cone instability. He also shows that warm ions trapped at the midplane can stabilize this instability, even though the instability is driven at a location removed from the midplane. This is the first experimental verification of the stabilizing effect of trapped ions for a sloshing-ion distribution.

• Research Organization: California Univ., Davis, CA (USA)
• OSTI ID: 5463695
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
CHARGED PARTICLES
INSTABILITY
ION MOBILITY
IONS
LOSS CONE INSTABILITY
MAGNETIC MIRRORS
MOBILITY
OPEN PLASMA DEVICES
PARTICLE MOBILITY
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PLASMA MICROINSTABILITIES
STABILIZATION
TANDEM MIRRORS
THERMONUCLEAR DEVICES
TMX DEVICES
TRAPPED-PARTICLE INSTABILITY
TRAPPING