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. The electrons are fired into one end of the tube by an electron gun. Comparison has been made with the results in normal triode operation and has shown a good agreement. Klystron multi cavity klystron, reflex klystron, working. Klystron power supply, klystron tube, isolator, frequency meter, variable attenuator, detector mount, waveguide stand, vswr meter and bnc cable.
The major difference between klystron and twt is that klystron cavities are replaced by structure of helix shape in twt. Since the velocity of electrons is modulated by the field, klystron are called velocity modulated devices. To read and print pdf files, download adobe acrobat reader. Proposed satellite power stations, where solar energy is to be converted to microwave energy and beamed to earth to be converted to ac. Klystron and microwave department capabilities and xband. A gridded electron gun for a sheet beam klystron unt. A microwave source of surprising range and endurance pdf. Two cavity klystron amplifiers working, amplification and. A collector is present at the end to collect the electrons. The other cavity is called the catcher cavity or output cavity. Initially intended for accelerator applications, the gun can operate at a higher perveance than one with a cylindrically symmetric beam.
We will establish the necessary formalism to understand klystron bunching phenomena which can be used to describe rf accelerator cavity. The gun design 3 and the collector design 4 are presented in this conference. Other articles where two cavity klystron is discussed. Microwave engineering ece questions and answers page 2. The reflex klystron makes use of velocity modulation to transform a continuous electron beam into. Efficiency calculations of resonant coupled cavity output. By lowering the qs of the cavities and by introducing intermediate cavities, wider bandwidth operation can be achieved. The high power part of the top implart rf system foresees the use of a number of identical rf plants each based on a thales 10 mw klystron th2157a and its power supply modulator. Important psu questionmicrowave,emt,communicationpart3.
It is a lowpower device used primarily for two purposes. In a klystron, an electron beam interacts with radio waves as it passes through resonant cavities, metal boxes along the length of a tube. Klystron modulators for the 3 tev clic scheme an overview p. Klystron fundamentals electron beam from gun is launched and magnetically confined to avoid contact. The london jazzfusion ensemble navigate themes of faith and struggle on their latest lp, toying with dub, hiphop and soul as they go. This tube is called a reflex klystron because it repels the input supply or performs the opposite function of a klystron. A new cold cathode klystron oscillator in the thz range is presented. A klystron tube makes use of speedcontrolled streams of electrons that pass through a resonating cavity.
A 500 kw lband klystron with broad bandwidth for sub. Cavity of a repeller klystron another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron repeller klystron. Electrons in a klystron are accelerated to a controlled speed by the application of several hundred volts. The cavity interaction is subtle, because the fields in the cavity modify the bunching of the beam within the cavity itself usually very dramatically. Ece questions and answers on microwave engineering with explanation for various interview, competitive examination and entrance test. The simplest klystron tube is the two cavity klystron. Microwave engineering cavity klystron tutorialspoint. Let us understand twt and klystron basics before we look into comparison between the two. Stability analysis of cband 500kw klystron with multicell output cavity jihyun hwang department of physics, postech, pohang 37673 sungju park and won namkung pohang accelerator laboratory, pohang 37874 moohyun cho department of advanced nuclear engineering, postech, pohang 37673. The physical components of a twocavity klystron consist of an electron emitter, two resonant cavities, a solenoid magnetic circuit to focuses the electron beam, and. Distortions of the gap impedance of the active cavity of a. Klystron amplifiers may use intermediate cavities to aprevent the oscillations that occurs in two cavity klystron bincrease the bw cimprove the power gain dincrease the efficiency of the klystron ansa q114 the twt is sometimes preferred to the multicavity klystron amplifier,because the formar.
Apr 25, 2008 this paper describes the development of an electron gun for a sheet beam klystron. Klystron vs magnetrondifference between klystron,magnetron. Due to the number of the resonant cavities klystrons are divided up into. After passing through the resonant cavity they are reflected by a negatively charged reflector electrode for another pass through the cavity, where they are then collected. Diploma sem v two cavity klystron amplifier microwave and radar lecture vidyalankar duration.
A klystron is a specialized linearbeam vacuum tube, invented in 1937 by american electrical. Large gun focus magnet helps launch beam into drift tube with minimum interception. The difference between reflex and twomulti cavity klystron is that, reflex klystron uses single cavity for modulationdemodulation. The beam couples to the input rf and gains energy in a series of cavities as it moves vertically up the klystron, then radiates strongly into an output cavity and, finally, is dumped into a resistive load. The disk model requires too long computer time, and the space charge wave theory is rather simplistic.
Interaction in klystron occurs only at the gaps of resonant cavities. I think u1 may have to do with getting the reflex klystron started. The reflex klystron is mostly used as a microwave oscillator. Tuning measurement of multicavity klystrons in diode mode.
Modeling and design of the thz klystron cavity, bunching grid, repeller and output structure based on silicon technology are. The whole structure of the three cavity klystron upconverter. A klystron is a microwave vacuum tube using cavity resonators to produce velocity modulation of the electron beam and produce amplification. In the reflex klystron, the electron beam passes through a single resonant cavity. The gain of both waves can be determined from the prototype of the periodic structure shown in fig. The frequency of operation of a klystron is set by the sizes of the input and output cavities. It consists of an electron gun, a filament surrounded by cathode and a focusing electrode at cathode potential. Although a small deviation has been found in tuning. The electrons are originally accelerated to high velocity by a potential of several hundred volts and enter a narrow gap that forms part of a cavity resonator system see. A klystron uses one or more special cavities, which modulate the electric field around the axis the tube. Klystronmodulators for the 3 tev clic scheme an overview. Klystron import data india with hs code, klystron importers.
Lowfrequency klystron for accelerator applications article pdf available in ieee transactions on nuclear science 243. The modulator switch, the pulse transformer between the modulator and the klystron, and the. Pdf lowfrequency klystron for accelerator applications. In font of cavity resonator a huge crowed of electrons assembles and excites cavity, the oscillation it the cavity takes place and hence we get the r. These electrons move at a uniform speed towards the anode until they are attracted by it. The external q of the input and output cavities was optimized to be 615 and 1514, respectively. Design study of rf section and cavities for cepc 650 mhz klystron. A klystron amplifier uses different cavities which control the electric field around the axis of the tube. The klystron as a power amplifier is modeled by the rf current generator driving the waveguide with circulator. The principle of velocityvariation, first used in heil oscillators, was also used in other microwave amplifying and oscillating tubes. Electron beams are produced from a source and the cavity klystrons are employed to amplify the signals. Firstly, as we know that klystrons are used as amplifiers for microwave frequency and conventional vaccum tubes cant be used due to interelectrode capacitance and lead. Understandexplain is the principle of working for two cavity klystron with velocity diagram. To study the characteristics of the reflex klystron tube and to determine its electronic tuning range.
A klystron is a specialized linearbeam vacuum tube evacuated electron tube the name klystron comes from the stem form. F input signal to the buncher cavity with the help of loop coupling. Obtain electronic efficiency from two cavity klystron. Let a beam of electrons, which has been accelerated by a. Cavity control system advanced modeling and simulations. The output cavity radiation, generally tens of megawatts at the same 2. Draw the equivalent circuit diagram of a reflex klystron.
A klystron is basically a vacuum tube with input and output structures replaced with resonant cavities known as buncher cavity and catcher cavity. Klystron import data of india and price seair exim solutions provides the latest, 100% genuine and trusted indian import data of klystron. Klystrons article about klystrons by the free dictionary. Wband klystron upconverter driven by pseudospark sourced.
Klausst 72fvm 36betwixt 22 reflex klystron, volker muehlhaus 21asdf44 the process is referred to as modulation. A millimeterwave klystron upconverter with a higher order. Up to now, the main sections of the klystron for cepc have been designed. Hannurkar raja ramanna centre for advanced technology, indore, india.
Explain with suitable sketch the operation of two cavity klystron amplifier. Lowpower klystrons are used as oscillators in terrestrial microwave relay. The electron beam first passes through a cavity to which the input signal is applied. Large focus magnet at collector inlet to overfocus beam and. Microwave electronics because of the presence of the electron beam, this amplifier periodic structure can propagate both a growing wave and a decaying wave in the direction of electron flow. Anatoly krasnykh, slac, box 4349 stanford, ca 94309.
A sutton tube, or reflex klystron, is a type of vacuum tube used to generate microwaves. Abstract the design and simulation of a multibeam reentrant type cavity with four beams is presented for a 350 mhz, 250 kw cw klystron. It covers basics of klystron and magnetron and mention difference between them. The power coupling from klystron to the sc cavity will be twostage impedance transforming see figure 3.
It is known by this name due to its reflex action of electron beam. The efficiency of the output section of broadband klystron with resonant copled cavity is calculated. There are often several regions of reflector voltage where the reflex klystron will oscillate. Xband products cpi xband klystrons are mostly used in military radar systems hundreds per year currently made tens of thousands made over the last 60 years. This is being done by simulating klystron performances for various cavity parameters including the number of cavities, inter cavity distance, and cavity tuning frequencies. When switch on the circuit, the electrons starts emitting from the cathode. The whole set up is as shown in the following figure. Klystron 250kw superheterodyne, single or dual down conversion with image reject mixing 114 dbm typical up to 105 db 16bit modular, multichannel digital receiver, signal processor up to 8192 15m time domain or spectrumbased time estimation and processing step an advanced adaptive clutter identification, mitigation and noise reduction. Oct 01, 2014 microwave linearbeam tubes 0 type 90 introduction we turn now to a quantitative and qualitative analysis of several conventional vac uum tubes and microwave tubes in common use. Reflex klystron oscillator pdf source of an electronbeam and the radiofrequency por tion of the klystron is independent of the electron source.
What are the high frequency limitations of conventional tubes. Klystron, thermionic electron tube that generates or amplifies microwaves by controlling the speed of a stream of electrons. At a very high temperature, the cathode emits electrons. In the solution of that problem, neither the time integrated electron disk model nor the space charge wave theory is used. A new modified method is proposed, with which the computer time is. Each klystron type, operating as a television visual rf amplifier, will deliver 5.
The design for the rf interaction region including cavity design is presented in this paper. The conventional vacuum tubes, such as triodes, tetrodes, and pentodes, are still used as signal sources of low output. Pdf circuit analysis of kaband extended interaction klystron. Tight controls are used to stabilize the phase among the several klystron outputs. The vacuum tube consists of a cathode, which is heated by a filament.
Reflex klystron reduced power from the bunches, in reflex klystron, reduces the reflex klystron of the cavity oscillations and causes a decrease in output power. Figure 922 shows the schematic diagram of a twocavity klystron amplifier. In this video, i have explained two cavity klystron amplifier with following points 1. Department of electronics and communication subject microwave engineeringeec 603 unitiii 1. In this tube there are two microwave cavity resonators, the catcher and the buncher. A 500 kw lband klystron with broad bandwidth for subharmonic bunching in the clic test facility v. The brothers russell and sigurd varian of stanford university are the. A technique for averaging of the gap impedance in beam transport channels on the basis of calculation of the coordinates of the center of gravity of the real part of gap impedance function obtained by means of numerical simulation is proposed. Other articles where twocavity klystron is discussed.
In particleincell pic simulations, when the klystron upconverter is driven by a 30 kv, 0. The essential elements of klystron are electron beams and cavity resonators. Abstract the design and simulation of a multibeam reentrant. Klystron iris hole coupler waveguide te10x cavity fpc superconducting cavity. Stability analysis of cband 500kw klystron with multi. The dependence of these characteristics on the beam current, beam voltage, re flector voltage, load, and other klystron design factors. Stability analysis of cband 500kw klystron with multicell. The reflex klystron contains a reflector plate, referred to as the repeller, instead of the output cavity used in other types of klystrons. It will help you in many ways such as you can generate competitive analysis reports on importer, port, supplier and exporter of klystron. 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. We suppose the negative half cycle of the input signal. F output from the cavity with the help of loop coupling.
Vidyalankar group of educational institutes 947 views. The clic compact linear collider design is based on. Klystrons are the most efficient of linear beam microwave tubes. The same method has been applied to tuning measurement of a diode pulsed klystron, e3712. By covering all the topics like transmission lines, modes of propagation, types of transmission lines, waveguides, components, avalanche transit time devices, microwave devices, eplane tee, hplane tee, eh plane tee, ratrace junction, directional couplers, cavity klystron, reflex klystron, travelling wave tube, magnetrons, measurement. Electron passing through the gap will interact with this field and change their velocity. The rediscovery of velocity modulation at stanford would probably have been no more successful than heils initial research in russia, except for the rumbatron. Transfer curve of a six cavity klystron upconverter. Download memotech electrotechnique pdf files vorremusongde.
Circuit analysis of kaband extended interaction klystron. The klystron tube 2k25 is a single cavity variable frequency microwave generator of low power and low efficiency. When used as an amplifier, the weak microwave signal to be amplified is applied to the buncher cavity through a coaxial cable or waveguide, and the amplified signal is extracted from the catcher cavity. At regions far from the optimum voltage, no oscillations are obtained at all. Jun 02, 2014 i am reading two cavity klystrons but not able to understand at all. The power is split in 4 or 2 parts depending on the needs of the fed structures. High efficiency klystron for the sps application by a. The rediscovery of velocity modulation at stanford would probably have been no more successful than heils initial research in. Microwave engineering cavity klystron for the generation and amplification of microwaves, there is a need of some special tubes called as microwave tubes. This page on klystron vs magnetron describes difference between klystron and magnetron. The klystron was invented at stanford university in 1937 and originally used as the oscillator in radar receivers during world war ii. Pdf in this article, we explained about the design of extended interaction klystron. Klystron power specifications based on transient beam loading analysis in damping rings. Pdf klystron power specifications based on transient.
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