Total absorption of electromagnetic radiation in overdense plasma

Abstract

The energy transformation from electromagnetic wave to plasmas polaritons in overdense plasma is investigated by using the theory of hydrodynamics in the thin cylinder limit and surface wave resonator. The grating experiment certifies the excitation of the surface wave. Through studying the role of the magnetic field in excitation of the surface wave and analyzing the frequency domain spectrum of the reflected wave, the time series of reflection, transmission and plasma density are diagnosed when the electromagnetic wave transforms into the surface wave. The experimental scheme of Bliokh [Phys. Rev. Lett. 95, 165003 (2005)] is improved. A steady overdense plasma in a cylindrical cavity is obtained by dc high voltage discharging and measurement is taken in series. The diffraction grating is fixed in optimum position after the distance from it to the chamber is adjusted. The reflection ratios of plasma and a piece of tinfoil are compared to avoid the effect of the standing wave. The effect of incident polarization is discussed and a measurement result is obtained with a 70Gauss magnetic field. Further research on scanning measurement reveals that the collision rate is the only determinant element of the half absorption width. Numerical simulation is given, based on the theory of surface plasmons (SPs). The experimental data agree with the numerical simulation well near the resonance frequency f=5GHz, while on the trailing edge, the curve is obviously expanded. The mechanism of these phenomena is very complex and other conceivable factors must exist during the excitation of SPs, which should be studied in the further research.

Colloquium: Unusual resonators: Plasmonics, metamaterials, and random media

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Experimentally investigate ionospheric depletion chemicals in artificially created ionosphere

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“…In the experiment, we utilize microwave interferometry to diagnose the plasma electron density, 23 and the frequency of the microwave is 10 GHz. The working gas air is injected into the vacuum chamber from a valve in the anode to reach the required pressure, and the background pressure is 10 À3 Pa.…”

Resonant Transparency of a Three-Layer Structure Containing the Dense Plasma Region

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