Performance evaluation of klystron beam focusingsystem with anisotropic ferritemagnet yasuhiro fuwa department of physics, kyoto university, kyoto, kyoto 6068502, japan yoshihisa iwashita institute forchemicalresearch, kyoto university, uji, kyoto 6110011, japan abstract. The electronic tuning range of the reflex klystron is usually referred to as the variation in frequency between half power pointsthe points in the oscillating mode where the power output is half the maximum output in the mode. Cavity of a repeller klystron another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron repeller klystron. Another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron figure 29. The working of reflex klystron is somewhat similar to the working of twocavity klystron. In klystron strong electrostatic fields are required for its operation efficiently.
What is the principle of operation of a multicavity klystron. Reflex klystron is a microwave device that works on principle of velocity modulation in addition to current modulation. Anatoly krasnykh, slac, box 4349 stanford, ca 94309. So, electron beam is injected from the cathode and that injected beam travel with a uniform velocity till the cavity. In this klystron, a single pair of grids does the functions of both the buncher and the catcher grids. A reflex klystron consists of an electron gun, a cavity with a pair of grids and a repeller plate as shown in the above diagram. Explain the operation principle of the cavity klystron with neat sketch. Moreover it uses repeller inplace of catcher cavity. For the same rf power and comparable efficiency, the beam voltage is half of the klystron one. A klystron looks and works something like an organ pipe. Pdf merge combinejoin pdf files online for free soda pdf.
I have a doubt on how exactly a reflex klystron worksas an rf source. Modern semiconductor technology has effectively replaced the reflex klystron in most applications. Slacpub16466 increasing klystron efficiency using com and. A klystron is a specialized linearbeam vacuum tube, invented in 1937 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. Proof of principle experiment on photonic crystal reflex. Photonic crystal reflex klystron using cold cathode. A klystron is basically a vacuum tube with input and output structures replaced with resonant cavities known as buncher cavity and catcher cavity. It covers basics of klystron and magnetron and mention difference between them. Important question and answers on reflex klystron with. The difference between reflex and twomulti cavity klystron is that, reflex klystron uses single cavity for modulationdemodulation. What is the difference between the two cavity klystron.
A klystron is a vacuum tube that can be used either as a generator or as an amplifier of power, at microwave frequencies. Reflex klystron consists of an electron gun, a cathode filament, an anode cavity, and an electrode at the cathode potential. Klystron amplification, power output, and efficiency can be greatly improved by the addition of intermediate cavities between the input and output cavities of the basic klystron. Reflex klystron oscillator operation application of. Principles for design of high power pulsed microwave devices. Typical operational problems with a klystron input drive power is too low and klystron is not saturated although this is required if the tube is included in a feedback loop reduced output power, efficiency, and increased output power amplitude jitter wrong cathode filament current wrong perveance. Let a beam of electrons, which has been accelerated by a. So, it works for all operating systems including mac, windows, and linux. The klystron is a device for amplifying microwave frequency signals that achieve high levels of power gain by applying vacuum tube principles and the concept of electron bunching. The operation of reflex klystron is understood by some assumptions. Klystrons are used in satellite systems, television broadcast, and radar, as well as particle accelerators and medicine. Reflex klystron working, oscillator and applegate diagram. Quickly merge multiple pdf files or part of them into a single one. Their work was preceded by the description of velocity modulation by a.
Avalanche diode construction, working and its applications. An avalanche diode is a one kind of diode that is designed to experience an avalanche breakdown at a particular reverse bias voltage. Before outlining its history, it is useful to sketch out the operating principles of the device. In general depending upon the bunching cycles, there are n plus 3 by 4 mode n reflex. Difference between two cavity klystron and reflex klystron. Using the merger diagram, obtain the maximal compatibles. Download and install the soda pdf desktop app to edit, compress, split, secure and merge. The power gain of a two cavity klystron amplifier is about 30 db. In order to achieve higher overall gain, one way is to connect several twocavity tubes in cascade, feeding the output to each of.
To study the characteristics of the reflex klystron tube and to determine its electronic tuning range. In wikipedia it says that, the electrons are fired into one end of the tube by an electron gun. It is given the name reflex klystron because of its reflex action of electron beam. Klystron vs magnetrondifference between klystron,magnetron. Blowing into the organ pipe produces a flow of air. Why is pulse modulation required in reflex klystron. This online pdf merge function is completely cost free and easy to use.
Klystron works on the principle of velocity modulation of electrons. A free and open source software to merge, split, rotate and extract pages from pdf files. The reflex klystron contains a reflector plate, referred to as the. The klystron amplifier is a device used to amplify microwave frequency signals that reach high stages of power gain by applying the principles of the vacuum tube as well as the electron bunching concept. The reflex klystron contains a reflector plate, referred to as the repeller, instead of the output cavity used in other types of klystrons. The klystron was the first embodiment of the velocity. The bunching cavities regulate the speed of the electrons so that they arrive in bunches at the output cavity. The application for klystron with integral cavities is usually credited in the early 1939 to hahn and metcalf and to russell and sigurd varian, two brothers that. The losses due to circuit factors can be reduced by a judicious use of the microwave. Additional cavities serve to velocitymodulate the electron beam and produce an increase in the energy available at the output. This article discusses about a brief information about the construction and working of an avalanche diode.
Klystron anps and oscillators were in common use during wwii. Merge pdf documents or other files to one pdf file. Klystron power supply, klystron tube, isolator, frequency meter, variable attenuator, detector mount, waveguide stand, vswr meter and bnc cable. Explain the bunching process of a twocavity klystron and derive. At regions far from the optimum voltage, no oscillations are obtained at all. Increasing klystron efficiency using com and bac tuning and application to the 5045 klystron aaron jensen, andy haase, erik jongewaard, mark kemp and jeff neilson technology and innovation directorate slac national accelerator laboratory menlo park, ca, usa, 94025 abstract. Thales electron devices rf sources for vllc mbk option 2 mbk principle and technology are the ones of a conventional klystron. For a proofof principle experiment, a 10 ghz reflex klystron adopting the photonic crystal and the field emission cathode was also analytically and numerically designed. The electron beam is accelerated towards the anode cavity. This time, however, the reference electron is taken as one that passes the gap on its way to the repeller at the time when the gap voltage is zero and going negative. Two cavity klystron is a amplifier where as reflex klystron is an oscillator. I am working on a design concept and possibly an engineering spec on. What is probably the primary advantage of the reflex klystron over the twocavity klystron is the mechanism used to tune the device. Reflex klystron article about reflex klystron by the free.
Klystron rf stabilization using feedforward circuit. This page on klystron vs magnetron describes difference between klystron and magnetron. It has two microwave cavity resonators the catcher and the buncher. In klystron coaxial resonators are used, the input power to the klystron is fed via coaxial, located in the wall between the first and second resonators and apples into the first resonator via its central coaxial. Reflex klystron is also known as a sutton klystron. Multi cavity klystron two cavity klystron used as lowpower microwave amplifier two. What is a klystron amplifier, types, differences and their. There are often several regions of reflector voltage where the reflex klystron will oscillate. This name is given by the name of its inventor robert sutton, it allow the passage of electron beam through a single resonant cavity. The klystron was the first embodiment of the velocity modulation principle. In this video, i have explained reflex klystron with following points 1.
Klystron types there are two basic configurations of klystron tubes 1. The reflex klystron makes use of velocity modulation to transform a continuous electron beam into. Microwave engineering cavity klystron tutorialspoint. Nov 07, 2012 for the love of physics walter lewin may 16, 2011 duration. This tube is called a reflex klystron because it repels the input supply or performs the opposite function of a klystron. So, working principle of reflex klystron is velocity and current modulation. Reflex klystron used as a lowpower microwave oscillator 2. The principle of velocityvariation, first used in heil oscillators, was also used in other microwave amplifying and oscillating tubes. Microwave engineering cavity klystron for the generation and amplification of microwaves, there is a need of some special tubes called as microwave tubes. The uhf region range of klystron amplifier ranges from 300 mhz3 ghz to 400 ghz. The main difference between two cavity reflex klystron amplifier.
The modulator is the dc power supply for the klystron. Klystron multi cavity klystron, reflex klystron, working. The bunches of electrons excite microwaves in the output cavity of the klystron. Reflex klystron free download as powerpoint presentation. Klystron and microwave department capabilities and xband.
In order to reduce the energy jitter pulsetopulse, a stabilization of the klystron modulator output is essential. Performance evaluation of klystron beam focusingsystem with. Klystron is a microwave generator compare slacs large, highpower microwave generator klystron below with this much smaller one magnetron right from a typical microwave oven. On this channel you can get education and knowledge for general issues and topics. This allows initiating the input resonator symmetrically. A singlecavity klystron in which the electron beam is reflected back through the cavity resonator by a repelling electrode having a negative voltage. The reflex klystron is mostly used as a microwave oscillator. Work supported by department of energy contract deac0376sf00515 abstract major changes to the next linear collider nlc design were facilitated by the experimental testing of the 75 mw xband klystron at a 3. This microwave generator, is a klystron that works on reflections and oscillations in a single cavity, which has a variable frequency. As with the multicavity klystron, the operating mechanism is best understood by considering the behavior of individual electrons. Microwave engineering reflex klystron tutorialspoint. Pdf2go does the work for you, but the original is, of course, not altered. This paper describes a new deq circuit with feedforward compensation to stabilize the output pulse amplitude of the existing modulator for the pulse klystron. The microwaves flow into the waveguide, which transports them to the.
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