Modeling inductively coupled plasmas: The coil current boundary condition

In modeling inductively coupled plasmas, the boundary condition for the electromagnetic field equations can be treated by specifying either the current in the induction coil or the total power dissipated in the plasma. This paper presents a method for using the coil current boundary condition. An advantage of using the coil current boundary condition is that coil current, unlike plasma power dissipation, is easily measured; in this approach the plasma power dissipation is an outcome of the calculation. The results of sample calculations are presented, covering a range of coil currents from 59 to 110 A. The conditions of the calculations correspond to experimental argon plasmas at atmospheric pressure and at 3.0 MHz frequency. The calculated isotherms are in good qualitative agreement with photographs of the laboratory plasmas.