First Observation of Plasma Motion in GAMMA 10 Using a Fast Camera

Abstract

Visible imaging measurement using a fast camera in conjunction with a gas puff was demonstrated in the GAMMA 10 tandem mirror. In order to image plasma behavior on the periphery, a hydrogen gas puff in the bottom of the vacuum chamber near the GAMMA 10 central-cell was used. Without the gas puff the light emission was not sufficiently bright, and SN ratio is not good. By using the gas puff, the light emission could be clearly observed, and a 5 - 6 kHz vibration of the plasma column was confirmed. This motion is most likely plasma rotation due to the electron drift wave and Er × B drift. These results show that the fast camera used in conjunction with a gas puff is a promising candidate for the measurement of peripheral plasma behavior even in low-density mirror plasmas.