Vortexlike turbulent structures in hot-ion mode plasmas with several keV are observed in the case with a radially produced weak shear of electric fields E(r). However, a strong E(r) shear formation due to a high ion-confining potential phi(c) production clears up these vortices together with plasma-confinement improvement and disappearance of both drift-wave and turbulencelike Fourier spectral signals. These findings are based on three-time progress in phi(c) in comparison to phi(c) attained 1992-2002. The significant advance of phi(c) is well extended in line with proposed potential-formation physics scalings.
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 E r × 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.
Advances in potential formation have led to remarkable discoveries on the effects of radial electric field distribution on turbulence suppression and transverse loss reduction. In order to study the improvement in plasma confinement because of the formation of plasma confinement potential, we constructed a multi-channel microwave interferometer system that can measure the density and density fluctuation radial profiles in a single plasma shot. We obtained clear density fluctuation suppression by the formation of the plasma confinement potential. Therefore, we have a powerful diagnostic tool with which to study the improvement in plasma confinement.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.