Assessment of hot-electron microstability in the initial TMX-U experiments

Technical Report · Fri Apr 01 04:00:00 EST 1983

DOI:https://doi.org/10.2172/6046750· OSTI ID:6046750

Casper, T A; Chen, Y J; Ellis, R; James, R; Lasnier, C

During the initial TMX-U experiments, we investigated the sloshing-ion and hot-electron distributions. We require these components to ultimately construct a thermal barrier for improved tandem mirror confinement. The plasma parameters we achieved approach values required for thermal barrier operation but have been limited by the power available. This report is concerned with the stability of the hot electron distribution formed. Nonthermal microwave emissions near the electron-cyclotron frequency f/sub ce/ of the minimum end-cell magnetic field indicate the presence of electron microinstabilities, which we have tentatively identified by their frequencies. We observed the upper-hybrid loss-cone mode (f/f/sub ce/ approx. 1.1) during high density operation with a relatively small fraction of hot electrons. At lower density operation with a higher hot electron fraction, we observed emissions consistent with the whistler instability. During emission bursts at 12.5 GHz (f/f/sub ce/ approx. 0.9) we observed a rapid rise in the high frequency thermal emissions, indicating a spreading of the distribution. Some of the more violent bursts are correlated with enhanced end loss currents.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6046750
• Report Number(s): UCID-19783; ON: DE83012837
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
CONFINEMENT
ELECTROMAGNETIC RADIATION
ELECTRON TEMPERATURE
INSTABILITY
MAGNETIC MIRRORS
MICROWAVE RADIATION
NOISE
OPEN PLASMA DEVICES
PLASMA CONFINEMENT
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES
RADIATIONS
RADIO NOISE
RADIOWAVE RADIATION
THERMAL BARRIERS
THERMONUCLEAR DEVICES
TMX DEVICES
WHISTLERS