Modulator and testing testing of the sbk includes the bsd test where the electron gun and bsd are processed at a 34 s. The design of a sheetbeam electron gun with planar cathode was made with the help of a threedimensional electrostatic field solver that was. Petillo science applications international corporation 1710 goodridge drive, mclean, va 22102 h4. Pdf highperveance wband sheetbeam electron gun design. The electron gun produces a beam of highspeed electrons focused to a small spot on the screen. Sheet beam gun design is a challenge in achieving required flatness and laminarity over the length of rf beam interaction.
The design and construction of a 100 kw peak power, 2% duty, pcm focused, wband sheet beam klystron is discussed. Jan 29, 2015 in this paper, a cold cathode based sheetbeam plasma cathode electron gun is reported with achieved sheetbeam current density. Beam current is compared to theoretical space charge limited flow. Electron guns are used in many vacuum electron devices to convert electrical. 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 electron beam gun is located either inside the vacuum chamber or stationary on the outside figure 14. An extended theoretical method used for design of sheet. Elliptical sheet beams are easy to focusing than rectangular sheet beams. This paper examines the design considerations for a magnetized sheet beam for which the electrons have energy both perpendicular and parallel to the. Figure 1 a shows the 3d beam transport model, including the sheet beam electron gun and the pcm structure, of the prototype wsbk ampli. As an example, ccr recently designed a sheet beam gun for an xband klystron 2. Sheet beam gun design is a challenge in achieving required flatness and laminarity over the. Furthermore, the design of the electron gun was verified using beam dynamics code egn2w and cstparticle studio 6,7. Experimental results are compared to model predictions.
Sheet beam is employed in thz devices as the beam offers an effective interaction with the rf signal. Design and performace of a 30 kv electron gun with ten. 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. Dudas physical sciences inc 603 king street, alexandria, va 22314 abstract an electron gun has been designed which will produce dual. 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. In our prior works, we successfully proved at wband that the magnet design provided 99% beam transmission of a 10. Design and performance of a 30 kv electron gun with ten. The tools yield parameters for rudimentary gun geometry, which are further refined using the 2d. Closeup of the phosphorcoated inner side of the screen cathode ray tube electron gun. Design of sheetbeam electron gun with planar cathode for. The elliptical cross section beam is produced by a new electron gun design using a cylindrical cathode and a racetrack shaped focus electrode. Estd has developed compact, lowvoltage multiplebeam and sheetbeam electron gun designs capable of generating peak beam. 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.
Our current eh150v, eh300v and eh800v electron beam guns are the most powerful in the world. Design of electron gun and novel ppm focusing system for w. Pdf progress on a gridded electron gun for a sheet beam. And the periodic elliptic magnetic field has successfully been designed and fabricated. As per the published literature, sheet beam shape is obtained by using complicated shapes of cathode, bfe and anode. 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. Scandate dispenser cathode fabrication for a highaspect. It has been observed that emission of electrons take place from the edge of. Pdf investigation of beam performance parameters in a. Ccr is developing rectangular, gridded, thermionic dispensercathode guns for sheet beam devices. For the qualitative assessment of the sheetbeam, an arrangement of three isolated metallicsheets is proposed. Sheet beam electron gun design for millimeter and submillimeter wave vacuum electronic sources by defense technical information center. P, operating at beam voltage 6 kv and 564 ma current.
A sheet beam electron gun focused by a periodic elliptic magnetic field is designed in this paper. As rf power is pushed to higher levels, space charge forces in the electron beam. Design of electron gun and novel ppm focusing system for wband sheet beam twt abstract. Building an electron gun is a highly technical and timeconsuming process. The multigap cavities produce acceptable values of rq and are designed to produce a. Design, fabrication and rf testing of nearthz sheet beam twta. Mask for separating beams for red, green, and blue part of displayed image 7. Pdf design of sheet beam electron gun researchgate.
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. 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. Apr 25, 2008 this paper describes the development of an electron gun for a sheet beam klystron. The gun topology flexibly permits adjustment of beam width to accommodate various interaction circuits while maintaining beam height. 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 current generation of accelerators typically use klystrons with a cylindrical beam generated by a piercetype electron gun. Pdf a gridded electron gun for a sheet beam klystron. The rudimentary gun geometry consists of a cathode in the form of a circular arc of halfangle.
At midwest tungsten service, we manufacture electron beam. Absolute cleanliness and attention to detail is used to make all our electron guns. Electron beam transport analysis of wband sheet beam klystron. It is hoped that mems fabricated microscale vacuum electron devices will pave the way for the elimination of. 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. Investigation of beam performance parameters in a piercetype electron gun.
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. Electron beam welding process, applications and equipment. To fully exploit its potential, a sheet beam electron gun has been utilized. As an example, ccr recently designed a sheet beam gun for an x. 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. Glowdischargecreated electron beams mountain scholar. The electron gun accommodates a physics experiment requiring a sheet electron beam to be swept while immersed in an axial 6. Deposition rates typically range from 5 to 25 lbshr 2. 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. The current generation of accelerators typically use klystrons with a cylindrical beam generated by a pierce. 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. The cathode ray tube crt consists of an electron gun, deflecting apparatus, and luminescent screen. However, a proper gun for the sheet beam tunnel of the designed circuit will provide much better transmission. As per the published literature, sheet beam shape is obtained by using.
In this paper, a cold cathode based sheetbeam plasma cathode electron gun is reported with achieved sheetbeam current density. The gun was tested up to 50 kw at 5a and10 kv, achieves power density of 33 kwcm2 at the target. 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. In this paper, a cold cathode based sheetbeam plasma cathode electron gun is reported with achieved sheet beam current density. The paper describes the considerations of designing elliptical sheet beam electron gun. 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. The gun is a magnetroninjection gun modified for planar geometry. In the beam area, the computer simulation analysis. Designing a converging beam electron gun and focusing solenoid with trak and permag. Guns can be focusable for small spot size, for use in applications such as xray production, welding and rheed. In an oscilloscope, the beam is deflected horizontally x by a.
A sixty beam electron gun with planer cathode has been simulated using opera 3d code 9. A gridded electron gun for a sheet beam klystron unt. As per the published literature, sheet beam shape is. The gun topology flexibly permits adjustment of beam width to accommodate various interaction circuits. The generating, forming and focusing of electron beam is one of the key technologies of the sheet beam klystrons. Lateral gun electrodes have not been designed as yet, but fig. Incoming voltage options make telemark power supplies suitable for all locations. Our more than 50 years of experience are reflected in over 400 electron beam systems installed worldwide.
Highperveance wband sheet beam electron gun design abstract. To demonstrate these advantages, a beam stick gun, magnet, beam tunnel, and collector is being fabricated to generate and transport a 19. P has been designed to replace the single beam electron gun of 1. A sheet beam electron gun with electromagnetic focusing using egun and cstps was simulated. Our customers also use us as a reliable second source manufacturer to meet unanticipated demand. The resulting electron gun are fabricating, and the gun s performance will be. Computer optimized design of electron guns nc state university. The following is a recount of my personal efforts in finding a stable source of 0. The gun geometry was generated in solidworksr with. A preliminary design of sheetbeam electron guns can be made using an approach pioneered by pierce1. A sixty beam electron gun with individual beam perveance 0.
Metal additive manufacturing 3d printing sciakys ebam do. This contract involved the design and test of a novel sheet like electron gun using lanthanum hexaboride lab6 as the cathode material. The technology developed should be applicable to sheet beam klystrons, backward wave oscillators, traveling wave tubes, and planar free electron lasers. The ebam package provides a precisely controlled beam geometry that. Design and construction of a wband sheet beam klystron. Pdf sheet beam is employed in thz devices as the beam offers an effective interaction with the rf signal. Electron guns are assembled by highly trained and skilled technicians who also have prior electron gun building ex perience. The sheet electron beam vacuum electron device is an attractive choice for generating high power millimeterterahertz wave radiation.
Several high magnification optical inspections and measurements are recorded during the build. 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. Introduction the electron gun accommodates a physics experiment requiring a sheet electron beam to be swept while immersed in an axial 6. Development of a 220 ghz 50 w sheet beam travelling wave tube. Vk intercepting gridded pierce gun m592 outline drawing performance parameters are based on a perveance gap of 0. The design of elliptical sheet beam electron gun ieee. Ccr is developing rectangular, gridded, thermionic, dispenser. Design principles for a sheet beam electron gun for a quasioptical gyrotron. The first application is expected to be klystrons for advanced particle accelerators and colliders. A strong history of reliable electron beam source ebeam gun power supplies is critical to process success.
Initially intended for accelerator applications, the gun can operate at a higher perveance than one with a cylindrically symmetric beam. This paper describes the development of an electron gun for a sheet beam klystron. Design and simulation of electron gun for a multibeam. The gun will be built, tested, and delivered to the stanford linear accelerator center for use in their sheet beam klystron.
Electron guns for medical and industrial linacs altair usa. An 20 kv, 210 ma electron gun for a sheet beam traveling wave tube have been designed. It is hoped that mems fabricated microscale vacuum electron devices. The electron gun employs a concentric packing topology with four pcds 12. Experimental investigation of a 1 kacmsup 2 sheet beam. Depressed collector is used for recovering kinetic energy from the spent electron beam. Design of gridded sheet beam electron gun request pdf. The design of electron and ion guns, beams, and collectors.
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. The cathode temperature was uniform over a length of 120 mm of the cathode surface. Ccr is developing rectangular, gridded, thermionic, dispensercathode guns for sheet beam devices. Experimental investigation of a 1 kacm 2 sheet beam. This paper represents the design of multibeam sixtybeam electron gun and focusing system for high. Designing a convergingbeam electron gun and focusing solenoid with trak and permag. Commercial applications and other benefits as described by the awardee. Experimental investigation of a 1 kacm2 sheet beam plasma. This was followed by application to a sheet beam gun for an xband klystron. Design and analysis of an electron beam in an electron gun. Electron beam transport analysis of wband sheet beam. 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.
We offer power supplies for single source or multiple source operation. Cathode technology the cathode acts as an electron source, emitting a beam through a process known as thermoionic emission. 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 general, the equipment is more complicated than that in a. A gridded electron gun for a sheet beam klystron nasaads. 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. Total current is measured by a loss ring across the isolation ceramics and the beam is collected at the collector plate at right.