Plasma sources and characterization in the r.f. test facility

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 .