Dependence of the energy confinement time on the density, safety factor, and major radius of the column in the T--13 tokamak

The time scale of the energy confinement in electrons, tau/sub E/, has been studied as a function of various parameters of the plasma column in the T--13 tokamak: the discharge current, the safety factor, and the major radius, in the region where tau/sub E/ depends linearly on the plasma density. This region is typical of tokamaks. Three regimes, differing in empirical behavior, have been observed. Their existence is manifested in a nonmonotonic dependence of tau-circumflex/sub E/ = tau/sub E// on the plasma current. In discharges in which tau-tilde/sub E/ is at a maximum, the behavior tau/sub E/proportionalqR/sup <1/.88$ is found. At higher and lower currents, and correspondingly at lower values of tau/sub E/, the R dependence is weaker