Biasing Experiments with a Ti Electro de in the Tohoku University Heliac

Improvement of plasma confinement was observed in the Tohoku University Heliac (TU-Heliac) when the Titanium (Ti) electrode was biased positively. In addition, the electron density and the line intensity of H increased by about 10-fold as compared with those before biasing when the Ti electrode was biased negatively. The latter phenomenon, which was not observed by negative biasing with a stainless steel electrode, suggested that the Ti electrode emits electrons/neutral particles into the plasma when biased negatively.