Study of Distribution of the Electric Field in a Plasma Chamber with Slot Input of Microwave Energy

AbstractIn this paper, a ridge rectangular waveguide is designed, and its cutoff frequency, impedance and electric field intensity are given by formulas or curves. A few ceramic samples are sintered in it by microwave energy. It is concluded that the device can be as a satisfactory microwave sintering cavity.

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Microwave curing process and mechanical properties study of epoxy mortars for repairing concrete pavement rapidly

Journal of Reinforced Plastics and Composites ◽

10.1177/0731684416683026 ◽

2016 ◽

Vol 36 (6) ◽

pp. 443-451 ◽

Cited By ~ 4

Author(s):

Xu Zhang ◽

Xiaoqun Wang ◽

Xuehong Xu ◽

Yueqing Zhao

Keyword(s):

Fly Ash ◽

Electric Field ◽

Electromagnetic Fields ◽

Electric Field Distribution ◽

Microwave Energy ◽

Concrete Pavement ◽

Optimum Process ◽

Curing Process ◽

Microwave Curing ◽

Mechanical Strengths

Polymer mortars are used frequently to repair pavement owing to their excellent properties (mix flexural strength ≥5.75 MPa, compressive strength ≥25 MPa). To repair concrete pavement with polymer mortars rapidly, uniform microwave energy can be used to reduce hardening time of polymer mortars. In this study, the distribution of electromagnetic fields in an industrial microwave facility was optimized, and an area AG with uniform and intensive electric field was obtained. Then microwave curing process of epoxy mortars containing fly ash in the area AG was optimized, and mechanical strengths of the epoxy mortars cured in the optimum process were tested. The results show that, although the distribution of electromagnetic fields in the microwave facility is non-uniform overall, there still are some brush-fire areas, where electric field distribution is relatively uniform. Epoxy mortars added with 10 wt% fly ash can be cured rapidly (approximately 20 min) in the area AG and exhibit outstanding mechanical strengths, which can be used to repair concrete pavement rapidly.

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Modelling and Study of a Microwave Plasma Source for High-rate Etching

Proceedings 17th International Conference on Microwave and High Frequency Heating ◽

10.4995/ampere2019.2019.9757 ◽

2019 ◽

Author(s):

Steffen Pauly ◽

Andreas Schulz ◽

Matthias Walker ◽

Günter Tovar ◽

Monika Balk ◽

...

Keyword(s):

Electric Field ◽

Field Distribution ◽

Electric Field Distribution ◽

Microwave Plasma ◽

Substrate Surface ◽

Plasma Source ◽

Production Costs ◽

Optical Measurements ◽

Real Field ◽

Plasma Chamber

The aim of the study is to optimize an existing microwave powered remote plasma source (RPS) with respect to the etching rate and gas temperature and to simplify the setup to save production costs. The RPS, which is shown in figure 1, is a low-pressure plasma source where the plasma is generated and exists mainly in the chamber of the source. Only radicals migrate out of the RPS. This is one important feature, that the plasma source is used for etching processes when ion bombardment and high thermal strain of the substrate must be prevented. The etching process is a chemical process, where the radicals react with the substrate surface atoms forming gaseous molecules. The benefit is a damage-free, dry and clean substrate surface. To achieve these goals, a FEM-based model of the RPS has been developed to investigate the microwave distribution and the microwave coupling into the plasma chamber, as well as the plasma itself. In this paper different examples of FEM based microwave simulations by different conditions and their experimental validations will be presented. To compare the calculated electric field distribution in the RPS with the real field distribution, PMMA-substrates were placed inside the plasma chamber of the source. They are heated up by the electric field and evaluated with an infrared camera and liquid crystal sheets. Both the measured and the calculated field distribution show a very good conformity. When the electric field is high enough in the plasma chamber the plasma ignites, the electron density and thus the permittivity and the conductivity increase, which changes again the electric field distribution. For this purpose, the FEM-model has been extended by the Drude model1. The model considers the equation of motion with a damping term for the electrons, leading to an expression for the conductivity. Results for various electron densities as well as their corresponding electric field distributions are presented and compared with optical measurements. Fig. 1. The figure shows the scheme of the RPS with its main components and functions.

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Resolution in photoelectron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100086593 ◽

1991 ◽

Vol 49 ◽

pp. 458-459

Author(s):

G. F. Rempfer

Keyword(s):

Electron Microscopy ◽

Electric Field ◽

Ultraviolet Light ◽

Uniform Field ◽

Virtual Image ◽

Lens System ◽

Photoemission Electron Microscopy ◽

Planar Electrode ◽

Electron Lens ◽

Photoemission Electron

In photoelectron microscopy (PEM), also called photoemission electron microscopy (PEEM), the image is formed by electrons which have been liberated from the specimen by ultraviolet light. The electrons are accelerated by an electric field before being imaged by an electron lens system. The specimen is supported on a planar electrode (or the electrode itself may be the specimen), and the accelerating field is applied between the specimen, which serves as the cathode, and an anode. The accelerating field is essentially uniform except for microfields near the surface of the specimen and a diverging field near the anode aperture. The uniform field forms a virtual image of the specimen (virtual specimen) at unit lateral magnification, approximately twice as far from the anode as is the specimen. The diverging field at the anode aperture in turn forms a virtual image of the virtual specimen at magnification 2/3, at a distance from the anode of 4/3 the specimen distance. This demagnified virtual image is the object for the objective stage of the lens system.

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Field-assisted ionization theory for microscopists

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171833 ◽

1994 ◽

Vol 52 ◽

pp. 820-821

Author(s):

Patrick P. Camus

Keyword(s):

Electric Field ◽

Electron Tunneling ◽

Ionization Probability ◽

Critical Distance ◽

Tunneling Probability ◽

Field Ionization ◽

Radius Of Curvature ◽

Field Evaporation ◽

A Value ◽

Ion Emission

The theory of field ion emission is the study of electron tunneling probability enhanced by the application of a high electric field. At subnanometer distances and kilovolt potentials, the probability of tunneling of electrons increases markedly. Field ionization of gas atoms produce atomic resolution images of the surface of the specimen, while field evaporation of surface atoms sections the specimen. Details of emission theory may be found in monographs.Field ionization (FI) is the phenomena whereby an electric field assists in the ionization of gas atoms via tunneling. The tunneling probability is a maximum at a critical distance above the surface,xc, Fig. 1. Energy is required to ionize the gas atom at xc, I, but at a value reduced by the appliedelectric field, xcFe, while energy is recovered by placing the electron in the specimen, φ. The highest ionization probability occurs for those regions on the specimen that have the highest local electric field. Those atoms which protrude from the average surfacehave the smallest radius of curvature, the highest field and therefore produce the highest ionizationprobability and brightest spots on the imaging screen, Fig. 2. This technique is called field ion microscopy (FIM).

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