An analytic expression for the surface impedance for electron heating
in inductively coupled discharges is derived from the kinetic equation
with the optimum ordering that nu similar to omega. Here, nu is the e
lectron collision frequency, and omega is the frequency of the driven
current inside the antenna coil. The expression is valid for both coll
isional and collisionless discharges, and can be employed in the model
ing of the source. (C) 1996 American Institute of Physics.