Investigation of the absorption process of the microwave radiation by metal wires with the same electrical conductivity

Abstract

In this paper, we present a microwave-assisted absorption method for the metallic wires with same electrical conductivity (e.g. tungsten and molybdenum). Our experimental set-up uses a microwave plasma generator in order to generate the plasma from the metal wires and to obtain the metal powders. The microwave plasma generator (experimental model) contains a cylindrical cavity— propagation modes, a magnetron with 800 W microwaves power and 2.45 GHz frequency, a power supply and an electronic module. In the focal point of the cylindrical cavity we have a high energy of the electromagnetic radiation. The metallic wires from this are a was vaporized and ionized. The structure of the metal powders was investigated with scanning electron microscopy. The electron temperature regarding metallic plasma produced was estimated using the ratio of atomic emission lines acquired by a high definition of the optical multichannel spectrometer. We obtained a strong microwave absorption by tungsten (W) and molybdenum (Mo) wires which depend on the power of the microwave. The Mo and W wires can be vaporized with the microwave field, in air at atmospheric pressure and room temperature.

A New Method for Tungsten Oxide Nanopowder Deposition on Carbon-Fiber-Reinforced Polymer Composites for X-ray Attenuation

“…To use CFRPs as electromagnetic shields, they must be made opaque for ionizing radiation via the deposition of a layer of metallic nanopowder. The generation and deposition of metallic nanopowders using laser ablation and plasma methods are performed at high temperatures [10,11], and the composite materials are degraded at temperatures above 200 • C [12]; therefore, this research assessed the possibility of simultaneously synthesizing and depositing tungsten oxide nanopowders onto the surface of CFRPs using a new microwave plasma generation method in atmospheric air. This new method uses the direct interaction of microwaves with an electrically insulated tungsten wire to create hot plasma and metallic nanopowders.…”