The Effects Induced by Microwave Field upon Tungsten Wires of Different Diameters

Abstract

The effects induced by microwave field upon tungsten wires of different diameters were investigated. Tungsten wires with 0.5 and 1.0 mm diameters were placed in the focal point of a single-mode cylindrical cavity linked to a microwave generator and exposed to microwave field in ambient air. The experimental results showed that the 0.5 mm diameter wire was completely vaporized due to microwaves strong absorption, while the wire with 1 mm diameter was not ignited. During the interaction between microwaves and tungsten wire with 0.5 mm diameter, a plasma with a high electronic excitation temperature was obtained. The theoretical analysis of the experiment showed that the voltage generated by metallic wires in interaction with microwaves depended on their electric resistance in AC and the power of the microwave field. The physical parameters and dimension of the metallic wire play a crucial role in the ignition process of the plasma by the microwave field. This new and simple method to generate a high-temperature plasma from a metallic wire could have many applications, especially in metal oxides synthesis, metal coatings, or thin film deposition.

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

“…The waveguide was constructed to match the TM 011 (transverse magnetic) propagation mode, its role being to focus the electric field of the microwaves into a single point located on the cylindrical cavity axis. If the magnetron generates a microwave power of 800 W, in the focal point of the waveguide there will be 8 MW/cm 2 [19]. When an electrically insulated metallic wire is placed with one end in the focal point of the waveguide and irradiated, it will emit electrons through the field emission effect [20].…”

Alfalfa (Medicago sativa) Sprouts Respiratory Responses to Cadmium Stress Using IR LPAS

“…For the experimental analysis, we used ~6 g of alfalfa seeds for every sample and the germination was carried out at room temperature. The seeds were grown in colorless polycarbonate containers (see Figure 4 ) with a specific volume of 0.83 cm³/g volume [ 25 , 26 ]. In each small container were added 6 g of alfalfa seeds over which we added 10 mL of distilled water for control samples or Cd for treated samples.…”

“…All experimental data were processed and stored by a computer. More details about the experimental system can be found in the articles already published [ 1 , 9 , 10 , 11 , 14 , 23 , 24 , 25 , 26 ].…”