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2 edition of High power microwave discharges in resonant cavities found in the catalog.

High power microwave discharges in resonant cavities

James Harvey Dell

High power microwave discharges in resonant cavities

  • 58 Want to read
  • 8 Currently reading

Published .
Written in English

    Subjects:
  • Physics Theses

  • Edition Notes

    Thesis (M.A.), Dept. of Physics, University of Toronto

    ContributionsAnderson, J. M. (supervisor)
    The Physical Object
    Pagination76 p.
    Number of Pages76
    ID Numbers
    Open LibraryOL20844693M

    For any viable thruster the thrusting force should increase with power, motivating testing at as high a power level as practical. However, resonant microwave cavities dissipate their RF power as Ohmic heating caused by induced currents in the resistive cavity walls, so higher RF power directly translates to an increased thermal load in the. Breakdown phenomena at window interfaces are investigated for microwave power levels of up to MW. The test stand utilizes a 3 MW magnetron operating at GHz, coupled to an S-band traveling wave resonant ring. resonant cavity. Produced by pulsed microwave power, the plasma is studied only when the microwave power is present. It was hoped that the parameters of the system would reach a steady state in the time of the microwave pulse so that a steady-state plasma produced by very large microwave power levels could be studied. There is a. Results of experiments with high-pressure helium and nitrogen discharges generated in a microwave resonant cavity for use in an electrothermal thruster are presented. The cavity, operating in the TM mode, generated the discharges within a quartz sphere, which allowed the discharge to be both free floating and away from solid surfaces.


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High power microwave discharges in resonant cavities by James Harvey Dell Download PDF EPUB FB2

Figure 7 shows typical discharge waveforms of the microwave power, EUV intensity, and visible light. The microwave power was measured by an electric probe in the resonant cavity.

The signal was normalized by P net. A solid-state oscillator was used. The cavity mode was TE and the Xe gas pressure was ~2– : Saya Tashima, Masami Ohnishi, Waheed Hugrass, Keita Sugimoto, Masatugu Sakaguchi, Hodaka Osawa, Hiro.

Resonant cavities; (a) Coaxial cavity, (b) Radial cavity, (c) Tunable cavity, (d) Toroidal cavity The principle, or fundamental, mode of oscillation of such cavity, and the one with the longest free-space wavelength, has electric and magnetic fields that do not depend on the azimuthal angle defining the half plane though both the axis and the Cited by: 2.

@article{osti_, title = {Resonant-frequency discharge in a multi-cell radio frequency cavity}, author = {Popovic, S and Upadhyay, J and Mammosser, J and Nikolic, M and Vuskovic, L}, abstractNote = {We are reporting experimental results on microwave discharge operating at resonant frequency in a multi-cell radio frequency (RF) accelerator cavity.

The Cavity Magnetron and Its Practical Signifi cance as a Major Innovation in T he industrial development of the cavity magnetron, and the subsequent development of high-power airborne and surface microwave radar, appear as a typical case of “major innovation,” i.e., according to the defi nition often used by.

Microwave discharges for excitation of CO/sub 2/ lasers have been investigated. A resonant microwave cavity ( GHz) has been employed to get high power TM/sub /-mode microwave excited high power CO/sub 2/ laser using a cylindrical resonant cavity - IEEE Journals & Magazine Skip to Main ContentCited by: Abstract: This paper presents the first experimental and theoretical investigation of high-power RF gas discharge as applied to RF front-end filters with critical air gaps in the 10s of μm.

Specifically, a strongly-coupled high-Q evanescent-mode resonant cavity is utilized as a vehicle in this study. This cavity tends to concentrate the resonant electric field in a small volume between its Cited by: A power supply in the radio frequency regime ( MHz) and another power supply in the microwave frequency regime ( GHz) are used to produce the plasma inside the cavity.

The effects of a time-varying complex dielectric constant upon the resonant characteristics of a cylindrical microwave cavity are presented. The cavity resonance equations are developed to consider the influence of small periodic changes in resonant frequency, bandwidth, and cavity-coupling coefficient upon the microwave power density within the cavity as a function of the probing microwave Cited by: 4.

Microwave discharges (MD) are widely used as a source of non-equilibrium low pressure plasma for different applications. This paper reviews the methods of microwave plasma generation at pressures from 10 −2 approximately to 30 kPa with centimeter–millimeter wavelength microwaves on the basis of scientific publications since up to the by: where (δf/f) is the ratio of the change in resonant frequency to the resonant frequency f o, and (Vo/Vc) the ratio of the empty cavity volume to the sample volume.

The constant C is a High power microwave discharges in resonant cavities book factor, which is for rectangular cavities and for circular cavities. The Magnetron. The MAGNETRON, shown in figureview (A), is a self-contained microwave oscillator that operates differently from the linear-beam tubes, such as the twt and the klystron.

View (B)is a simplified High power microwave discharges in resonant cavities book of the magnetron. CROSSED-ELECTRON and MAGNETIC fields are used in the magnetron to produce the high-power output required in radar and communications equipment. The cavity magnetron is a high-powered vacuum tube that generates microwaves using the interaction of a stream of electrons with a magnetic field while moving past a series of open metal cavities (cavity resonators).Electrons pass by the openings to these cavities and cause microwaves to oscillate within, similar to the way a whistle produces a tone when excited by an air stream blown past its.

Following the design and development of efficient surface wave launchers [8], the systematic investigation of such discharges started at the end of the seventies. Nonetheless it is really in the eighties that SW discharges proved their remarkable potential for modelling high frequency plasmas in general [9] and also for applications [10].Cited by: It is presented in [26] that the EVA cavities are gas-discharge-free for operating at a W power level, indicating that this design is within the safe range of high-power operation.

The two-pole. Fixed and variable length re‐entrant resonant cavities designed for the measurement of dielectric constant and dissipation factor are described.

These cavities operate in the frequency decade of to cycles per second, a region avoided by many experimenters because the frequency is too high for the application of circuit techniques and not high enough for the convenient use of coaxial Cited by: microwave sources in the lower average powers, it seems unlikely they could achieve the power levels of interest for HPM sources and linear colliders.

Fig. Peak power vs. average power domains for microwave production [1]. Figure 2 illustrates the technical progress over several decades in the Pf 2 (power times frequency squared, also. A New Concept for High Power RF Coupling between Waveguides and Resonant RF Cavities Chen Xu1, *, Ilan Ben-Zvi1, 2, Haipeng Wang3, Tianmu Xin1, and Liling Xiao4 Abstract|Microwave engineering of high average-power (hundreds of kilowatts) devices often involves a transition from a waveguide to a device, typically a resonant by: 1.

This book offers a broad coverage of the theory and practice of industrial microwave heating. It introduces the physical processes behind dipolar and conductivity loss mechanisms and follows with a thorough presentation of dielectric property data of many industrial materials as a function of the moisture content, temperature and frequency, focussing on the interpretation of such data as 5/5(2).

Resonant Cavities and Waveguides 12 Resonant Cavities and Waveguides This chapter initiates our study of resonant accelerators., The category includes rf (radio-frequency) linear accelerators, cyclotrons, microtrons, and synchrotrons.

Resonant accelerators have the following features in common: 1. Applied electric fields are harmonic. Mehrdad Mehdizadeh, in Microwave/RF Applicators and Probes (Second Edition), Cavity resonators as applicators or probes.

Resonant cavities are metal-enclosed resonant structures [13–15], where the dimensions are comparable with, or larger than, the operating such, practical cavities are almost exclusively operated at microwave frequencies ( MHz to 30 GHz), where.

This paper introduces a new concept in the detection and monitoring of the electric field intensity in high power microwave cavities. It is proposed that the optical emission intensity of a low-pressure gas plasma discharge can be used to describe the strength of the microwave electric field that is powering the : Ahmed Al-Shamma'a, Colin Fitzpatrick, Jim Lucas, Ionnais Pandithas, Elfed Lewis.

Abstract. This paper introduces a new concept in the detection and monitoring of the electric field intensity in high power microwave cavities. It is proposed that the optical emission intensity of a low-pressure gas plasma discharge can be used to describe the strength of the microwave electric field that is powering the : Ahmed Al-Shamma'a, Colin Fitzpatrick, Jim Lucas, Ionnais Pandithas, Elfed Lewis.

With these parameters, at Ghz microwave frequency the ratio of plasma frequency to microwave angular frequency in the active portion of the discharge is greater than one, and may be as high Cited by: @article{osti_, title = {Large-Volume Resonant Microwave Discharge for Plasma Cleaning of a CEBAF 5-Cell SRF Cavity}, author = {J.

Mammosser, S. Ahmed, K. Macha, J. Upadhyay, M. Nikoli, S. Popovi, L. Vuakovi}, abstractNote = {We report the preliminary results on plasma generation in a 5-cell CEBAF superconducting radio-frequency (SRF) cavity for the application of cavity interior Cited by: 1.

In order to successfully perform in situ cleaning of SRF cavities, it is necessary to ignite the plasma, control its intensity, and locate which cell is hosting the glow discharge, without having the possibility of looking inside the cavity RF volume.

This paper presents the complete procedure developed for in situ cleaning of GHz 9-cell TESLA-type cavities: plasma ignition, RF plasma Author: P. Berrutti, B. Giaccone, M. Martinello, A. Grassellino, T. Khabiboulline, M. Doleans, S. Kim, D. The resonant cavity, which is hollow and of the order of a few centimetres diameter, allows coupling of the microwave power into the plasma gas flowing through the capillary discharge tube.

The microwave power supply operates at a frequency of GHz. Microwave plasmas can be produced at atmospheric pressure, if the design of the cavity allows. The triggering switch initiates the microwave dis-charge in the waveguide volume and its plasma forma-tion controls the phase of the wave reflected from the corresponding tee arm and consequently the resonant cavity mode of operation.

The particular feature of high power RPC switches is their operation in an overvoltage when the micro. microwave energy is applied in a resonant cavity appllcator and ]s absorbed by a plasma discharge in the flowing propellant. The ignited plasma acts as a lossy load, and with optimal tuning, energy absorption efficiencies over 95 percent (based on the applied microwave power) are expected.

Nitrogen,File Size: 1MB. Evaluations for possible using of superconducting materials in high power microwave generators based on the method of the resonant microwave compression were made.

As an example the relationship between the power amplification factor and frequency was determined for superconducting rectangular cavities.

Capabilities of superconducting cavities as energy accumulators were : Sergey N. Artemenko, Valery L. Kaminsky, Gennady M. Samoylenko, Boris A. Alekseev. Microwave tubes are vacuum electron devices used for the generation and amplification of radio frequencies in the microwave range.

An established technology area, the use of tubes remains essential in the field today for high-power applications. The culmination of the authorOCOs 50 years of industry experience, this authoritative resource offers you a thorough understanding of the operations.

In this way, the resonant cavities are shown to have pulse shaping properties, with the photonic crystal cavity able to generate pulses with widths and delays ranging from tens of microseconds down to hundreds nanoseconds. A fluid plasma simulation was developed to model with high fidelity the transient dynamics of laboratory plasma discharges.

(“propellantless propulsion”) in a resonant microwave cavity • We have fabricated a resonant cavity and begun initial thermal testing – Cavity Q> – Anticipated initial power levels up to W • We have developed a new noncontact wideband RF power transmission joint, the “finger joint” – Measured loss.

A klystron is a specialized linear-beam vacuum tube, invented in by American electrical engineers Russell and Sigurd Varian, which is used as an amplifier for high radio frequencies, from UHF up into the microwave range. Low-power klystrons are used as oscillators in terrestrial microwave relay communications links, while high-power klystrons are used as output tubes in UHF television.

Chen, A. Semnani, and D. Peroulis, “High-power microwave gas discharge in high-Q evanescent-mode cavity resonator and its instantaneous/long-term effects,” IEEE International Microwave Symposium (IMS), Seattle, WA, A microwave cavity or radio frequency (RF) cavity is a special type of resonator, consisting of a closed (or largely closed) metal structure that confines electromagnetic fields in the microwave region of the spectrum.

The structure is either hollow or filled with dielectric material. The microwaves bounce back and forth between the walls of the cavity. At the cavity's resonant frequencies. Artemenko, SN, Gorev, SA, Igumnov, VS & Beverly, REHigh-power microwave pulse compressors with a variable geometry of accumulative resonant cavity.

in IEEE International Power Modulator and High Voltage Conference, IPMHVC, Institute of Electrical and Electronics Engineers Inc., pp.IEEE International.

Preliminary Investigation of High Power Microwave Plasmas for Electrothermal pressure and applied microwave power, and the discharge is maintained as the pressure and power are raised to The study reported here was conducted with a resonant cavity as the microwave File Size: 9MB.

N2 - Evaluations for possible using of superconducting materials in high power microwave generators based on the method of the resonant microwave compression were made.

As an example the relationship between the power amplification factor and frequency was determined for superconducting rectangular cavities. In microwave ovens, a waveguide leads to a port in the cooking chamber.

In lighting systems, such as sulphur lamps and metal halide lamps, magnetrons also produce a microwave field.

Types. Cavity magnetrons use a high-voltage DC power supply to bring a hot-filament cathode to a high negative potential. Permanent magnets located next to the. This page is somewhat unclearly written, as it is hard to tell when it is talking about microwave cavities and when it is talking about resonant circuits made with inductors and capacitors.

This is primarily in the first portion of the article, but it is rather confusing. reduced density gas channel by absorbing microwave power delivered to a surrounding resonant cavity.

This departs from the perturbation analysis and the exact theory since the discharge is formed by the resonant cavity fields, rather than simply placing a resonant cavity around an existing discharge. A particularly simple and compact microwave discharge generating device is the quarter wave coaxial cavity resonator (QWCCR).

This paper presents a new, compacted design of such a device. A simple approximate analysis of the quality factor, Q, which is a measure of the resonant electromagnetic potential step-up capability is given, and compared Cited by: 2.The size of the cavity must be adjusted to support a resonance at the desired operating frequency.

If the plasma volume is small, its effects on the resonant frequency are modest and one can estimate the required dimensions from the unperturbed values.

For example, the lowest mode of a "tall" cavity (height > radius) is a TE() mode, with.