Plasma Transport and Confinement Studies in Hanbit Mirror Device

Abstract

A brief overview is presented on initial study results of plasma transport and confinement in HANBIT mirror device. The parallel confinement is calculated using a generalized Pastukhov's formula, and compared with some experimental estimates. It is shown that the confinement time is less than 1 ms in typical HANBIT discharges. Analysis and simulation study are also presented on HANBIT discharges, particularly, ting to clarify the plasma density jump phenomena, which was observed in HANBIT when the RF frequency ω becomes smaller than the ion cyclotron frequency ω_ci. It is shown that the jump in plasma density (and beta, as shown from recent measurements) might be explained mainly as due to the increase in the parallel confinement time by the onset of ICRH ion heating at ω < ω_ci. The long-pulse operation with high-density plasma, even with a small initial fueling, can be also explained as due to the strong wall-recycling by fast neutrals generated from the ICRH heated hot ion at ω< ω_ci.