Effect of the sheath thickness of thin inhomogeneous plasma layer on the propagation constant for the surface waves

Abstract

Based on the dispersion equation obtained from the Helmholtz equation in the plasma sheath region and main plasma column for surface waves, the propagation constant properties on the interface of the plasma sheath region and main plasma column region are studied. The analytic formula of propagation constant for the azimuthally symmetric surface wave (m = 0 mode) and non-symmetric surface waves (m = 1, 2, 3, and 4 modes) on the interface is presented, which indicates the effect of the thickness of the plasma sheath region on the propagation constant characteristics. The analytical result shows that the thickness has a significant influence on the propagation constant when the thickness is 0.01 times smaller than the thickness of the main plasma column region for both the symmetric and non-symmetric surface waves, while there is a significant difference in the propagation constant amplitude between the m = 1 mode and other four modes.