Plasma sources and characterization in the rf test facility

In order to support the high-power r.f. experiments in the Hanbit large mag netic mirror device and to study low-temperature plasma processing applicat ions, an r.f. test facility (RFTF) was constructed. The RFTF has a total ch amber length of 1.5 m, maximum chamber diameter of 0.6 m and maximum magnet ic field of 1.2 tesla. In the RFTF, we have studied various plasma sources such as the ICP (inductively coupled plasma), ECR (electron cyclotron reson ance), Helicon and ICRH lion cyclotron resonance heating). From these exper iments, we present new experimental results related to a uniform plasma den sity profile. The characteristics of r.f. (4 MHz) discharges are investigat ed 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. T he results show that the plasma density is uniform over the diameter of 320 mm under a density regime of 10(10) cm(-3). (C) 1999 Elsevier Science S.A. All rights reserved.