A Simulation Study of the Factors Affecting the Collisional Power Dissipation in a Helicon Plasma

Abstract

Plasma density and magnetic field strength are modified to maximize the collisional power absorption in the helicon plasma. Simulations were done for two common types of RF antennas, namely, half-helix and Nagoya type-III. The simulations were performed with the CST Microwave Studio code. The finite-integration technique approach in the frequency domain has been used for the calculations. The power deposition profile calculated in this paper is validated against HELIC code. The method proved to be reliable, with accuracy depending on the appropriate number of constant radial density shells. CST code has the capabilities that calculate the power absorption for different antenna types at a given plasma density profile at various electron temperatures, magnetic fields, and plasma densities. At high magnetic fields power absorption is rather symmetric, independent to the plasma density. Our finding indicates that power profile is approximately symmetric at low plasma densities in the range of values explored for magnetic fields. It seems that the ratio of the plasma density to the magnetic field has an extreme effect on the axial power deposition profile.