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Encyclopedia > RF cavity
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A cavity resonator uses resonance to amplify an electromagnetic wave. The cavity has interior surfaces which reflects an electromagnetic wave of a specific frequency. When a wave that is resonant with the cavity enters, it bounces back and forth within the cavity, with low loss (See standing wave). As more wave energy enters the cavity, it combines with and reinforces the standing wave, increasing its intensity. In physics, resonance is the tendency of a system to absorb more energy when the frequency of the oscillations matches the systems natural frequency of vibration (its resonant frequency) than it does at other frequencies. ... A wave is a disturbance that propagates in a periodically repeating fashion, often transferring energy. ... A standing wave, also known as a stationary wave, is a wave that remains in a constant position. ...

Contents


Examples

Some common examples of cavity resonators include the klystron tube. In a microwave oven (see also magnetron), the tube of a flute, and the body of a violin (this latter also being an example of a Helmholtz resonator). The calculation of the exact magnetic field has mathematical complexities and involves the study of Bessel functions. Reflex klystron Type 2K25 or 723 A/B. The threaded adjustment rod on the right side allows the position of the reflector to be adjusted (by compressing the reflex cavity), and thus the natural resonant frequency of the device. ... A cavity magnetron is a high-powered vacuum tube that generates coherent microwaves. ... The flute is a musical instrument of the woodwind family. ... The pitches of open strings on a violin The violin is a bowed stringed musical instrument that has four strings tuned a perfect fifth apart, the lowest being the G just below middle C. It is the smallest and highest-tuned member of the violin family of string instruments, which... Acoustics is a branch of physics and is the study of sound, mechanical waves in gases, liquids, and solids. ... In mathematics, Bessel functions, first defined by the Swiss mathematician Daniel Bernoulli and named after Friedrich Bessel, are canonical solutions y(x) of Bessels differential equation: for an arbitrary real number α (the order). ...


Particle Accelerators and Particle Physics

Other examples of cavity resonators include the klystron tube Waveguide as in a particle accelerator that work in conjunction with a specifically tuned cavity by the configuration of the structures. On the beamline of an accelerator system, there are specific sections that are cavity resonators for RF. Reflex klystron Type 2K25 or 723 A/B. The threaded adjustment rod on the right side allows the position of the reflector to be adjusted (by compressing the reflex cavity), and thus the natural resonant frequency of the device. ... A waveguide used for propagating RF or electromagnetic waves. ... A 1960s single stage 2MeV linear Van de Graaff accelerator, here opened for maintenance A particle accelerator is a device which uses electric and/or magnetic fields to propel electrically charged particles to high speeds. ... Beamlines at synchrotrons are facilities at which researchers get access to synchrotron light, the tunable and high-energy X-ray beams used in synchrotron research. ...


Laser

In a laser, light is amplified in a cavity resonator which is usually composed of two or more mirrors. Thus an optical cavity, also known as a resonator, is a cavity with walls which reflect electromagnetic waves (light). This will allow standing wave modes to exist with little loss outside the cavity. The range of sizes in which lasers exist is immense, extending from microscopic diode lasers (top) to football field sized neodymium glass lasers (bottom) used for inertial confinement fusion. ... A cavity resonator uses resonance to amplify a wave. ... Electromagnetic radiation or EM radiation is a combination (cross product) of oscillating electric and magnetic fields perpendicular to each other, moving through space as a wave, effectively transporting energy and momentum. ... Prism splitting light Light is electromagnetic radiation with a wavelength that is visible to the eye (visible light) or, in a technical or scientific context, electromagnetic radiation of any wavelength. ...


Patents

  • U.S. Patent 2235506 -- High frequency tanks and resonant cavities -- S. A. Schelkunoff
  • U.S. Patent 2315313 -- Cavity resonator -- H. Bushholz
  • U.S. Patent 2357313 -- High frequency resonator and circuit therefor -- P. S. Carter
  • U.S. Patent 2357314 -- Cavity resonator circuit -- P. S. Carter
  • U.S. Patent 2372228 -- Ultra short wave radio system -- S. A. Schelkunoff
  • U.S. Patent 2444152 -- Cavity resonator circuit -- P. S. Carter
  • U.S. Patent 2611094 -- Inductance-capacitance resonance circuit -- H. B. Rex

  Results from FactBites:
 
Air-line microwave coaxial reversing switch having diagonally switched path - Patent 4618840 (2469 words)
In accordance with the present invention, the fifth connector bar 35 is situated on the side of the rf cavity unit 15 opposite the first four connector bars 31, 32, 33 and 34 and permits electrical connection of the first and third ports 21 and 23.
The rf cavity unit 15 is machined from conductive material, such as aluminum, and is physically and electrically connected to the outer conductors 41 of the ports to form a common ground.
The rf cavity unit 15, which has a generally squar cross-section, includes a square groove 51 extending from the top of the rf cavity unit nearly half-way down, so as to communicate with the center conductors 43 of the ports.
A 201-MHz RF Cavity Design with Non-Stressed, Pre-Curved Be Windows for Muon Cooling Channels (1564 words)
High-gradient RF cavities at 201 MHz are required for muon cooling channels in a neutrino factory or a muon collider, and also for a recently proposed international Muon Ionization Cooling Experiment (MICE) at Rutherford Appleton Laboratory (RAL).
A closed-cell (pillbox-like) cavity design was proposed and reported [1] where the beam apertures are electro-magnetically terminated by low Z and thin Be foils.
To keep the cavity from detuning due to RF heating power, these Be foils are under tension that is introduced by a small CTE (coefficient of thermal expansion) difference between the thin Be foils and thick Be window frame during the brazing process.
  More results at FactBites »


 

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