The Role of Plasma Biasing in the H‐Modes in the STOR‐M Tokamak

Abstract

H‐modes have been induced in the STOR‐M tokamak with various techniques, including short current pulses, electrode/limiter biasing, and compact torus injection.The common features of the H‐modes in STOR‐M include a sudden drop in the Hα radiation level, a significant increase in the electron density, and modification of the edge electron density and floating potential profiles. Other phenomena specific to certain types of H‐modes in STOR‐M will also be presented.

Simultaneous evolution of plasma rotation, radial electric field, MHD activity and plasma confinement in the STOR-M tokamak

“…This experimental observation is a consistent phenomenon of plasma fluctuation damping by electric field shear under the assumption that the temperature effect on the floating potential gradient is less than the electric field influence. Such plasma behavior is usually accompanied by H-mode transitions and has been observed during the induced H-Modes in STOR-M [1][2][3][4][5][6][7].…”

“…An important challenge for enhanced tokamak operation is the development and understanding of the basic physics involved in the process that leads to the transition to improved confinement modes. As shown in previous investigations [1][2][3][4][5][6][7], H-mode confinement in the STOR-M [8] tokamak can be induced through methods such as plasma biasing, current pulse (turbulent heating) and compact torus (CT) injection. Investigation of the plasma behavior in ohmic discharges without the aforementioned external factors provides a better understanding of STOR-M confinement.…”