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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, a...

The Korea Superconducting Tokamak Advanced Research (KSTAR) project is the major effort of the national fusion programme of the Republic of Korea. Its aim is to develop a steady state capable advanced superconducting tokamak to establish a scientific and technological basis for an attractive fusion reactor. The major parameters of the tokamak are: major radius 1.8 m, minor radius 0.5 m, toroidal field 3.5 T and plasma current 2 MA, with a strongly shaped plasma cross-section and double null divertor. The initial pulse length provided by the poloidal magnet system is 20 s, but the pulse length can be increased to 300 s through non-inductive current drive. The plasma heating and current drive system consists of neutral beams, ion cyclotron waves, lower hybrid waves and electron cyclotron waves for flexible profile control in advanced tokamak operating modes. A comprehensive set of diagnostics is planned for plasma control, performance evaluation and physics understanding. The project has completed its conceptual design and moved to the engineering design and construction phase. The target date for the first plasma is 2002.

We present a self-consistent model of solenoidal inductively coupled plasma (ICP) discharge, which can be useful to understand the discharge physics of the ICP. This model includes one-dimensional heating model and particle and temperature transport models. The heating model is based on the kinetic response of the plasma to the exciting RF wave including anomalous skin effect and modulation effect by chamber walls, which is the dominant mechanism at low pressure. The particle and temperature transports are expressed by one-dimensional fluid equations (continuity equation, momentum equation, and temperature equation). The argon discharges are simulated and the various results, such as the radial profiles of plasma density, electron temperature, induced electric field, and local power absorption are presented.

A large-area transformer coupled plasma (TCP) source has been designed and constructed. In our design, a plasma generation chamber and a radio-frequency (RF) antenna chamber have been separated with a dielectric material, and differentially pumped to accommodate large-area, relatively thin dielectric windows against mechanical pressures. With a large diameter (78 cm) chamber, a low frequency (4 MHz) RF source has been chosen. By calculating the plasma impedance from TCPRP codes based on a 2D heating theory [1], the diameter of a single-turn copper coil antenna was optimized to provide high-density plasmas in the large area. Also the impedance matching circuit of this large-area TCP source has been designed from the calculated plasma impedance.

In order to support the high-power r.f. experiments in the Hanbit large magnetic mirror device and to study low-temperature plasma processing applications, an r.f. test facility (RFTF) was constructed. The RFTF has a total chamber length of 1.5 m, maximum chamber diameter of 0.6 m and maximum magnetic field of 1.2 tesla. In the RFTF, we have studied various plasma sources such as the ICP (inductively coupled plasma), ECR (electron cyclotron resonance), Helicon and ICRH (ion cyclotron resonance heating). From these experiments, we present new experimental results related to a uniform plasma density profile. The characteristics of r.f. (4 MHz) discharges are investigated by using a double half turn antenna with a combination of limiters in a variety of the magnetic field, neutral gas pressures, and applied powers. The results show that the plasma density is uniform over the diameter of 320 mm under a density regime of 10 10 cm −3 .

A self-consistent model of transformer coupled plasma (TCP) discharge is developed, combining transport and heating models. The transport model is composed of electron and ion continuity and temperature equations. The heating model covers arbitrary values of the collision frequency, including collisionless heating mechanisms and modulation effects by walls.

Summary form only given, as follows. A fast-scanning system with single and triple electric probes is developed to characterize a new transformer coupled plasma (TCP) source, where magnetic field trapping is applied, as a commercial etching device. Radial variation of plasma density and electron temperature are measured and dependence of these parameters on the RF power and gas pressure are analyzed along with the optimal operating conditions. Comparisons are made between data by a triple probe and those by a single probe. Non-thermal properties of TCP will be discussed.