Investigation of the Conditions Required for the Formation of a Magnetic Neutral Loop Discharge Plasma

Abstract

In order to reveal the conditions required for the formation of a neutral loop discharge (NLD) plasma, distributions of excited atoms that are closely related to the distributions of the ionization rates were measured under various discharge conditions. Measurements of the distributions of these excited atoms were performed by laser induced fluorescence spectroscopy and optical emission spectroscopy. It was found that the results of these measurements were consistent with the theoretically predicted dependencies of electron heating on the magnetic field strength, the radio frequency (RF) electric field, and the frequency of the RF source. In addition, it was shown that the effects of electron-neutral collisions and of the finite size of the device set limitations on the formation of the NLD plasma.