Confinement Studies of Reversed Field Pinch Plasma on TPE-1Rm20

Confinement properties of a reversed field pinch (RFP), TPE-1Rm20, are intensively presented. Plasma current, I_p, dependencies of confinement properties are particularly shown in comparison with the forerunner machine, TPE-1RM15. The results without any active density controls are presented in this paper. It is shown that the both machines have almost the same, relatively high, I/N values (= 12×10^–14 Am) and the poloidal beta, β_p, (= 0.1) and they do not change very much with I_p, where N is the column density. The energy confinement time, τ_E, linearly increases with I_p and the behavior of the resistive part of the loop voltage has an important role to the I_p dependence of τ_E.