This paper presents the design of a sheet beam electron gun intended for use in an xband sheet beam klystron sbk. Investigation of beam performance parameters in a piercetype electron gun. Scandate dispenser cathode fabrication for a highaspect. Design, fabrication and rf testing of nearthz sheet beam twta. In this paper, a cold cathode based sheet beam plasma cathode electron gun is reported with achieved sheet beam current density. Mask for separating beams for red, green, and blue part of displayed image 7. Designing a converging beam electron gun and focusing solenoid with trak and permag. The resulting electron gun are fabricating, and the gun s performance will be. Figure 1 a shows the 3d beam transport model, including the sheet beam electron gun and the pcm structure, of the prototype wsbk ampli. The gun geometry was generated in solidworksr with. The gun will be built, tested, and delivered to the stanford linear accelerator center for use in their sheet beam klystron. P has been designed to replace the single beam electron gun of 1. First, the general characteristics of the sheet beam electron gun are discussed by dividing the gun into three investigation parts, and the design curves are derived theoretically.
Furthermore, the design of the electron gun was verified using beam dynamics code egn2w and cstparticle studio 6,7. A sheet beam electron gun focused by a periodic elliptic magnetic field is designed in this paper. As an example, ccr recently designed a sheet beam gun for an x. Specifically, the goal was to design and build a reliable high current density sheet like electron generator to facilitate detailed studies of the stable propagation of sheet like electron beams. The design considerations for a magnetized sheet beam for which the electrons have energy both perpendicular and parallel to the magnetic field are examined, including the basic design principles and scaling laws, the issue of orbit crossing and electrode synthesis in a sheet beam configuration, limiting currents both in the guide tube and across the resonator, and the edge. The ebam package provides a precisely controlled beam geometry that. Guns can be focusable for small spot size, for use in applications such as xray production, welding and rheed. Lateral gun electrodes have not been designed as yet, but fig. Design and analysis of an electron beam in an electron gun.
Kimball physics is a key supplier of electron guns designed for use in a wide variety of ultra high vacuum uhv surface physics, space physics, and processing applications. In our prior works, we successfully proved at wband that the magnet design provided 99% beam transmission of a 10. As per the published literature, sheet beam shape is obtained by using. Sheet beam is employed in thz devices as the beam offers an effective interaction with the rf signal. The design of electron and ion guns, beams, and collectors. It is hoped that mems fabricated microscale vacuum electron devices will pave the way for the elimination of. The current generation of accelerators typically use klystrons with a cylindrical beam generated by a pierce. Pdf sheet beam is employed in thz devices as the beam offers an effective interaction with the rf signal. Commercial applications and other benefits as described by the awardee. Pdf investigation of beam performance parameters in a. Pdf a gridded electron gun for a sheet beam klystron. The cathode ray tube crt consists of an electron gun, deflecting apparatus, and luminescent screen. This paper examines the design considerations for a magnetized sheet beam for which the electrons have energy both perpendicular and parallel to the.
Ccr is developing rectangular, gridded, thermionic, dispensercathode guns for sheet beam devices. Our current eh150v, eh300v and eh800v electron beam guns are the most powerful in the world. Bfe and anode dimensions are optimized using cst code to converge the beam coming from planar cathode of rectangular size 1. The design and construction of a 100 kw peak power, 2% duty, pcm focused, wband sheet beam klystron is discussed. Experimental investigation of a 1 kacm2 sheet beam plasma. And the periodic elliptic magnetic field has successfully been designed and fabricated.
Design and simulation of electron gun for a multibeam. The electron beam gun is located either inside the vacuum chamber or stationary on the outside figure 14. Dudas physical sciences inc 603 king street, alexandria, va 22314 abstract an electron gun has been designed which will produce dual. Sheet beam gun design is a challenge in achieving required flatness and laminarity over the length of rf beam interaction. Design principles for a sheet beam electron gun for a quasioptical gyrotron.
To test electron guns in the elephant vacuum chamber so that we as a team may obtain a means of testing our particle detectors used for the cascades 2 project. Figure 3 shows a magic 3d simulation of a gun which provides a beam 8mm thick, 8cm wide, with a beam current density of 50 acm2, and an area convergence of 10, i. A gridded electron gun for a sheet beam klystron nasaads. The current generation of accelerators typically use klystrons with a cylindrical beam generated by a piercetype electron gun. The sheet electron beam vacuum electron device is an attractive choice for generating high power millimeterterahertz wave radiation. Electron guns are used in many vacuum electron devices to convert electrical. A strong history of reliable electron beam source ebeam gun power supplies is critical to process success. A sheet beam gun analyzer was built to test the terahertz sheet beam gun and determine the size and current density of a sheet electron beam produced by the impregnated scandate tungsten dispenser cathode. Experimental investigation of a 1 kacm 2 sheet beam. A preliminary design of sheetbeam electron guns can be made using an approach pioneered by pierce1.
A design methodology for sheet beam formation and solenoidal magnetic field transport is described, and a point design for a wband amplifier gun and beam transport is presented. At midwest tungsten service, we manufacture electron beam. This paper represents the design of multibeam sixtybeam electron gun and focusing system for high. Glowdischargecreated electron beams mountain scholar. The following is a recount of my personal efforts in finding a stable source of 0.
The technology developed should be applicable to sheet beam klystrons, backward wave oscillators, traveling wave tubes, and planar free electron lasers. Highperveance wband sheet beam electron gun design abstract. Experimental results are compared to model predictions. Metal additive manufacturing 3d printing sciakys ebam do. Our more than 50 years of experience are reflected in over 400 electron beam systems installed worldwide. Experimental investigation of a 1 kacmsup 2 sheet beam. A sixty beam electron gun with individual beam perveance 0. In this paper, a cold cathode based sheetbeam plasma cathode electron gun is reported with achieved sheetbeam current density. For the qualitative assessment of the sheetbeam, an arrangement of three isolated metallicsheets is proposed. Design of gridded sheet beam electron gun request pdf. Building an electron gun is a highly technical and timeconsuming process. Introduction the electron gun accommodates a physics experiment requiring a sheet electron beam to be swept while immersed in an axial 6.
To fully exploit its potential, a sheet beam electron gun has been utilized. Several high magnification optical inspections and measurements are recorded during the build. Vk intercepting gridded pierce gun m592 outline drawing performance parameters are based on a perveance gap of 0. Initially intended for accelerator applications, the gun can operate at a higher perveance than one with a cylindrically symmetric beam. In the beam area, the computer simulation analysis. An 20 kv, 210 ma electron gun for a sheet beam traveling wave tube have been designed. Figure 1 below shows the internal structure of the slow wave device in both crosssection and 3d model, together with a scanning electron micrograph of half of the device directly machined into copper using a nanocnc machine. A sixty beam electron gun with planer cathode has been simulated using opera 3d code 9. As an example, ccr recently designed a sheet beam gun for an xband klystron 2. In an oscilloscope, the beam is deflected horizontally x by a.
Design of electron gun and novel ppm focusing system for wband sheet beam twt abstract. Electron source or electron gun is a device which provides electrons for accelerators it essentially needs an electron generation mechanism and an extraction mechanism the generation could be thermionic, field emission or photo emission extraction mechanism could be dc or rf electron source rf gun basics details of rf gun. Our customers also use us as a reliable second source manufacturer to meet unanticipated demand. We offer power supplies for single source or multiple source operation. The authors show that the electrode synthesis technique can be modified to shape edge electrodes in such a way as to minimize edge effects. The generating, forming and focusing of electron beam is one of the key technologies of the sheet beam klystrons. Electron guns are assembled by highly trained and skilled technicians who also have prior electron gun building ex perience. Sheet beam has very small space charge force as compared to a pencil beam of same beam current, and thereby requiring less magnetic field for beam focussing. Incoming voltage options make telemark power supplies suitable for all locations. Ccr is developing rectangular, gridded, thermionic, dispenser. An extended theoretical method based on pierce theory is investigated in this paper to provide a reliably support and direct approaches for the design of the general sheet beam electron gun. It is hoped that mems fabricated microscale vacuum electron devices. The elliptical cross section beam is produced by a new electron gun design using a cylindrical cathode and a racetrack shaped focus electrode.
Electron beam transport analysis of wband sheet beam klystron. Design principles for a sheetbeam electron gun for a. The gun was tested up to 50 kw at 5a and10 kv, achieves power density of 33 kwcm2 at the target. High current density sheetlike electron beam generator. Deposition rates typically range from 5 to 25 lbshr 2. One commonality of these electron beam welders is that all beam parameters and all mechanical axes are numerically controlled either by a plc or a cnc.
Pdf progress on a gridded electron gun for a sheet beam. This was followed by application to a sheet beam gun for an xband klystron. Electron beam welding process, applications and equipment. The first application is expected to be klystrons for advanced particle accelerators and colliders. The rudimentary gun geometry consists of a cathode in the form of a circular arc of halfangle. Scanning electron microscope sem n the goal of the sem is to scan a focused beam of primary electrons onto a sample, and to collect secondary electrons emitted from the sample to form an image n modern sems involve 5 main components u an electron source a. The gun is a magnetroninjection gun modified for planar geometry.
Design and construction of a wband sheet beam klystron. Pdf highperveance wband sheetbeam electron gun design. A sheet beam electron gun with electromagnetic focusing using egun and cstps was simulated. The design of a sheetbeam electron gun with planar cathode was made with the help of a threedimensional electrostatic field solver that was. The electron gun produces a beam of highspeed electrons focused to a small spot on the screen. In this paper, an electron gun was suggested that has an appropriate beam current, 200 ma, and a low level of beam loss in the e gun. The design of elliptical sheet beam electron gun ieee. Depressed collector is used for recovering kinetic energy from the spent electron beam. The gun topology flexibly permits adjustment of beam width to accommodate various interaction circuits. Design and performance of a 30 kv electron gun with ten. This contract involved the design and test of a novel sheet like electron gun using lanthanum hexaboride lab6 as the cathode material.
The paper describes the considerations of designing elliptical sheet beam electron gun. The cathode temperature was uniform over a length of 120 mm of the cathode surface. The electron gun accommodates a physics experiment requiring a sheet electron beam to be swept while immersed in an axial 6. This paper describes the development of an electron gun for a sheet beam klystron. P, operating at beam voltage 6 kv and 564 ma current. As rf power is pushed to higher levels, space charge forces in the electron beam. Electron guns for medical and industrial linacs altair usa. Elliptical sheet beams are easy to focusing than rectangular sheet beams. In this paper, a cold cathode based sheetbeam plasma cathode electron gun is reported with achieved sheet beam current density.
Absolute cleanliness and attention to detail is used to make all our electron guns. Cathode technology the cathode acts as an electron source, emitting a beam through a process known as thermoionic emission. The electron gun employs a concentric packing topology with four pcds 12. Apr 25, 2008 this paper describes the development of an electron gun for a sheet beam klystron. The electron beam formation, its focusing properties and the expansion and spreading of the beam over the collector surface need reliable tools for the design of magnetic shielding of solenoids as well as for the calculation of electron trajectories under the influence of electric, magnetic and self fields. As per the published literature, sheet beam shape is obtained by using complicated shapes of cathode, bfe and anode. Modulator and testing testing of the sbk includes the bsd test where the electron gun and bsd are processed at a 34 s. The tools yield parameters for rudimentary gun geometry, which are further refined using the 2d. Development of a 220 ghz 50 w sheet beam travelling wave tube. An extended theoretical method used for design of sheet. The design of a sheet beam electron gun with planar cathode was made with the help of a threedimensional electrostatic field solver that was capable of forming a sheet beam of 19 ma at 12 kv. The multigap cavities produce acceptable values of rq and are designed to produce a.
Beam deflection tubes, sometimes known as sheet beam tubes, are vacuum tubes with an electron gun, a beam intensity control grid, a screen grid, sometimes a suppressor grid, and two electrostatic deflection electrodes on opposite sides of the electron beam, that can direct the rectangular beam to either of two anodes in the same plane. To demonstrate these advantages, a beam stick gun, magnet, beam tunnel, and collector is being fabricated to generate and transport a 19. In general, the equipment is more complicated than that in a. Beam current is compared to theoretical space charge limited flow.
Design of electron gun and novel ppm focusing system for w. The gun topology flexibly permits adjustment of beam width to accommodate various interaction circuits while maintaining beam height. Electron beam transport analysis of wband sheet beam. Sheet beam electron gun design for millimeter and submillimeter wave vacuum electronic sources by defense technical information center. Petillo science applications international corporation 1710 goodridge drive, mclean, va 22102 h4. When a radio wave passes near this beam, the energy it absorbs from the beam serves to amplify the power of the wave, enabling an increased.
Computer optimized design of electron guns nc state university. For the qualitative assessment of the sheet beam, an arrangement of three isolated metallic sheets is proposed. Design of sheetbeam electron gun with planar cathode for. Sheet beam gun design is a challenge in achieving required flatness and laminarity over the. Estd has developed compact, lowvoltage multiplebeam and sheetbeam electron gun designs capable of generating peak beam. A gridded electron gun for a sheet beam klystron unt. It has been observed that emission of electrons take place from the edge of. Designing a convergingbeam electron gun and focusing solenoid with trak and permag. Total current is measured by a loss ring across the isolation ceramics and the beam is collected at the collector plate at right. Design and performace of a 30 kv electron gun with ten. However, a proper gun for the sheet beam tunnel of the designed circuit will provide much better transmission. Ccr is developing rectangular, gridded, thermionic dispensercathode guns for sheet beam devices. Closeup of the phosphorcoated inner side of the screen cathode ray tube electron gun.
As per the published literature, sheet beam shape is. Jan 29, 2015 in this paper, a cold cathode based sheetbeam plasma cathode electron gun is reported with achieved sheetbeam current density. Pdf design of sheet beam electron gun researchgate. The design of a sheet beam electron gun with planar cathode was made with the help of a threedimensional electrostatic field solver that was capable of forming a sheet beam of 19ma at 12kv.
1548 1037 1390 1427 863 554 938 1389 292 936 517 699 1127 1122 1441 813 162 487 1166 1548 920 652 1463 694 895 247 1635 1468 889 1109 690 552 1591 1619 33 526 1110 46 1031 208 134 923