Both geometrical and electrical asymmetry effects in capacitive argon discharges are investigated using a two-dimensional particle-in-cell coupled with Monte Carlo collision model. When changing the ratio of the top and bottom electrode surface areas and the phase shift between the two applied harmonics, the induced self-bias was found to develop separately. By adjusting the ratio between the high and low harmonic amplitudes, the electrical asymmetry effect at a fixed phase shift can be substantially optimized. However, the self-bias caused by the geometrical asymmetry hardly changed. Moreover, the separate control of these two asymmetry effects can also be demonstrated from their power absorption profiles. Both the axial and radial plasma density distributions can be modulated by the electrical asymmetry effect.

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Two types of methods have been previously used to relate the macroscopic decay of polarization in a dielectric specimen to a microscopic decay function defined in terms of molecular motions. The first is based on Kubo's theory of non-equilibrium statistical mechanics combined with Kirkwood's theory. T h e second is based on the use of Debye's rotational diffusion equation.Glarum has made a calculation of the first type, which predicts an exponential macroscopic decay in the case of a liquid assumed to have particularly simple properties. Scaife and the authors have made a calculation of the second type, whch for the same liquid agree with each other in predicting a non-exponential macroscopic decay, but disagree with Glarm's calculations.In this paper it is shown that, if Glarum's calculation is modified at one point, the results then agree with the calculations of the second type made by Scaife and the authors, The modification consists in the use, at a certain point, of a macroscopic decay function which we feel to be more justified physically than that used by Glarum.