The influence of impurity and particle control on TMX-U (Tandem Mirror Experiment Upgrade) plasma operation

Conference · Fri Nov 01 00:00:00 EST 1985

OSTI ID:6473134

Allen, S L; Yu, T L; Foote, J H; Pickles, W L

A variety of techniques are used in TMX-U to control impurities and reflux: repeated plasma pulses, glow discharge cleaning (GDC), and gettering. A series of experiments under three different plasma-wall conditions was performed: no wall conditioning after a machine maintenance cycle, a glow-discharge-cleaned wall, and a gettered wall. Several plasma diagnostics to determine the effect of these procedures on TMX-U plasma parameters were used. Spectroscopic measurements indicated that GDC reduced impurities and increased the electron temperature, enabling full-duration beam-sustained plasma operation without a large number of repeated plasma pulses. Gettering further reduced the impurities and the neutral pressure, and this improved condition persisted for several shots after gettering was stopped. Measurements from residual gas analyzers and an end-loss ion spectrometer indicated that hydrogen is present in the plasma during the initial deuterium operation after pumpdown; the hydrogen level decreased after plasma operation with gettering, indicating reduced wall recycling.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6473134
• Report Number(s): UCRL-93542; CONF-851174-43; ON: DE87009592
• Resource Relation: Conference: 32. AVS national vacuum symposium and topical conference, Houston, TX, USA, 19 Nov 1985; Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
TMX DEVICES
GETTERING
IMPURITIES
ECR HEATING
ELECTRON TEMPERATURE
EXPERIMENTAL DATA
GLOW DISCHARGES
NEUTRAL ATOM BEAM INJECTION
PLASMA WAVES
THERMAL BARRIERS
BEAM INJECTION
DATA
ELECTRIC DISCHARGES
HEATING
HIGH-FREQUENCY HEATING
INFORMATION
MAGNETIC MIRRORS
NUMERICAL DATA
OPEN PLASMA DEVICES
PLASMA HEATING
TANDEM MIRRORS
THERMONUCLEAR DEVICES
700103* - Fusion Energy- Plasma Research- Kinetics