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Based on the finite temperature plasma dielectric tensor model which contains the particle thermal effect, by numerically solving the eigenmode dispersion relation of electromagnetic waves propagating in radially uniform and magnetized warm plasma column which is surrounded by conducting boundary, the mode coupling characteristic and liner damping mechanism induced wave power deposition properties of helicon and Trivelpiece-Gould (TG) waves are parametrically analyzed. The detailed investigations show as follows. Under typical helicon plasma parameter conditions, i.e. wave frequency <i>ω</i>/(2π) = 13.56 MHz, ion temperature is much smaller than electron temperature, for the helicon wave, there exist a cut-off magnetic field <i>B</i>_0,H,cutoff and a cut-off plasma density <i>n</i>_0,H,cutoff, for which under the conditions of <i>B</i>₀ > <i>B</i>_0,H,cutoff or <i>n</i>₀ < <i>n</i>_0,H,cutoff, the helicon wave becomes an evanescent wave. When the magnetic field intensity changes from 48.4 to 484 G, i.e., <i>ω</i>/<i>ω</i>_ce ranges from 0.01 to 0.1, for the power deposition intensity, Landau damping of TG wave dominates for the <i>m</i> = 0 mode, meanwhile, for the <i>m</i> = 1 mode, which wave, i.e. helicon wave or TG wave, plays a major role in power deposition mainly depends on the magnitude of the magnetic field. On the other hand, for a given magnetic field <i>B</i>₀ = 100 G, when <i>ω</i>_pe/<i>ω</i>_ce changes from 3 to 100, for both the <i>m</i> = 0 mode and the <i>m</i> = 1 mode, the power deposition induced by Landau damping of TG wave plays a major role, further, one may notice that the power deposition of TG wave decreases while the power deposition of the helicon wave increases as plasma density increases. Finally, for both the <i>m</i> = 0 mode and the <i>m</i> = 1 mode, the power deposition due to the Landau damping plays a dominant role. All these conclusions provide us with some useful clues to better understanding the high ionization mechanism of helicon wave discharges.

Understanding the power deposition characteristic of high density helicon wave plasma source is critical for further investigating into the discharge mechanism of helicon wave discharge. Based on the warm plasma dielectric tensor model which contains both the particle thermal effect and temperature anisotropy and using the insulting boundary condition, the eigenmode dispersion relation of helicon wave and Trivelpiece-Gould (TG) wave propagating in radially uniform plasma column are numerically obtained. Then based on the eigenmode dispersion relation and exact field distribution in the plasma column, the mode coupling properties between the helicon wave and TG wave, the parametric dependence of the cyclotron damping properties of the electron cyclotron wave (TG wave) and power deposition properties of the <i>m</i> = –1, 0, +1 modes under moderate plasma density and low magnetic fields conditions are theoretically investigated in typical helicon plasma parameter range. The detailed investigations are shown below. Under typical helicon plasma parameter conditions, i.e. wave frequency <i>ω</i>/2π = 13.56 MHz and the ion temperature is one-tenth of the electron temperature, there exist a critical magnetic field value <i>B</i>_0,c and a critical electron temperature value <i>T</i>_e,c for which under the conditions of <i>B</i>₀ < <i>B</i>_0,c the helicon wave becomes an evanescent wave and the TG wave becomes an evanescent wave when <i>T</i>_e < <i>T</i>_e,c. The cyclotron damping of the TG wave dramatically increases as the wave frequency approaches to the electron cyclotron frequency. The TG wave becomes a growth wave when the ratio of perpendicular electron temperature to parallel electron temperature is above a certain value. For the high magnetic field, i.e. <i>ω</i>/<i>ω</i>_ce = 0.1, most of the power deposition is deposited in the central core region, while for the low magnetic field, i.e. <i>ω</i>/<i>ω</i>_ce = 0.9, the power is deposited mainly in the outer region of plasma column. For typical helicon plasma electron temperature range, <i>T</i>_e∈ (3 eV, 5 eV), the energy depositions induced by the collisional damping and Landau damping of the TG wave are dominant for different electron temperature ranges, which implies that different damping mechanisms have different heating intensities for electrons. Under current parameter condition, compared with the <i>m</i> = +1 mode, the <i>m</i> = –1 and <i>m</i> = 0 mode of the TG wave play major role in the power deposition process, although the cyclotron damping of the TG wave dominates the power deposition in this typical electron temperature range. All these conclusions provide some useful clues for us to better understand the high ionization mechanism of helicon wave discharge.

Based on the dispersion equation obtained from Helmholtz equation in the sheath region and plasma layer region, and free space region of the azimuthally symmetric surface wave, the propagation constant properties on the interface of the plasma layer region and free space region, the mode radiation enhancement characteristics in the free space region are studied. The analytical results indicate that the collision effect has an evident influence on the attenuation constant, but the impact on phase constant can be ignored when the wave frequency is equal to the plasma frequency. While the radiation enhancement phenomenon due to a plasma layer is confirmed, both the sheath thickness and plasma layer thickness have a notable effect on the amplitude of the maximum radiation enhancement intensity. These analytic results have an important theoretical guidance value in the optimization of plasma antenna radiation field.

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.