China lab6 cathode china lanthanum hexaboride, lab6. Iisc invites rfi to procure electron gun for research and experimentation in additive manufacturing area. Standard schottky electron guns with beam energy up to 10kev. Kimball physics kimball physics excellence in electron. Cathode physics welcome and electron sources poelker and. Kimball physics emitters provide a reliable source of electrons or ions for use in a variety of instruments including microscopy, lithography, xray generation, free electron lasers, electron accelerators, and other custom applications.
The hv deck contains electronics, power supplies, interlocks and energy stores 1sandia is a multiprogram laboratory operated by sandia. There are different electron beam sources which are different for the. The latter property has improved the microscopes spatial resolution at lower electron beam energies. Experiments have characterized the operation of a lab6 triode gun in a standard three. Development of electron guns for linacs and dc accelerator. Two electron gun cathode configurations a thermionic lab 6 with. The technical specification of the electron beam gun to be purchased is specified in the table 2. Electron linacs as possible ads drivers electron beam centre ni m binavi mumbai k. Abstract the accelerator and pulse po wer division of barc is presently constructing three industrial electron. This is a userfriendly workhorse for atomicresolution tem imaging and routine structural characterization. The electron gun system consists of a remotely located 7. Lab6 lanthanum hexaboride cathodes for electron microscopes. Other applications include kimball physics electron guns and ion guns. It is known that a converging or collimating beam of smaller beam diameter at the linac input will.
A novel numerical calculation method for electron guns. The electron gun under construction the electron microscope generates images by bombarding a sample with electrons and then transforming the results of that interaction into a viewable image. The most important requirement is for clean vacuum, with partial pressures of oxidizing gases being kept below 107 torr in the electron gun. The energy spread of a lab6 cathode operated in the virtual source. The low emittance dc electron gun is also supposed to be useful for applications such as smithpurcell fel 1. Study on compact dc electron gun using single crystal. We directly traced two bunches each of 5000 electrons from cathode to gun exit and considered two cases. Herniter, presented at the 1987 particle accelerator conference, washington, d.
The filament cathode is heated until a stream of electrons is produced. Jeol usa jsmit500hr high resolution, large chamber. Emissivity of lanthanum hexaboride thermionic electron gun. The emissivity of the thermionic electron gun cathode material lanthanum hexaboride lab 6 at an operating temperature of 1622 k has been measured for wavelengths from 550 nm to 2400 nm. Piercetype electron gun with a large concave lab6 cathode.
The low emittance dc electron gun at lns is one of the candidates. Simulations were carried out using cst particle studio. Electron gun the first and basic part of the microscopes is the source of electrons. Recently, electron guns with high brightness are of great interest to achieve many applications in the field of electron beam technology such as smithpurcell fel, for example. The scanning electron microscope sem is one of the most versatile instruments available for the examination and analysis of the microstructure morphology and chemical composition characterizations. Zakhary1 1accelerators and ion sources department, nuclear research center, atomic energy authority, cairo p. The condition of the cathode itself, along with that of the wehnelt aperture, may often be used to verify the partial pressures in the gun. The excellent imaging capability also makes the h9500 a platform for insitu tem. The dc electron gun project at lns to generate a high brightness gun with low emittance and long operational lifetime has been developped.
China lab6 cathode, find details about china lanthanum hexaboride, lab6 cathode electron gun from lab6 cathode cathay advanced materials limited. A series of images representing cross sections of the three. Evo can be tailored precisely to your requirements, whether you are in life sciences, material sciences, or routine industrial quality assurance and failure analysis. Furthermore, a table on the comparison of various electron sources in page1409 indicates that the lab 6 guns. Kp also manufactures unique, versatile, compact, multiport vacuum chambers.
A piercetype electron gun with a concave cathode of lanthanum hexaboride lab 6 30 mm in diameter is described. Comparison of electron guns characteristics of electron beam brightness current density per unit solid angle units of. Young, advanced energy systems aes, medford, ny, usa abstract commercial offtheshelf cots gridded thermionic cathode electron guns show promise for certain pulsed and cw electron beam applications. Pdf the energy spread of a lab6 cathode operated in the virtual. We have chosen single crystal lab6 as the thermionic cathode because it can. The emissivity of the thermionic electron gun cathode material lanthanum hexaboride lab at an operating temperature of 1622 k has been measured for wavelengths from 550 nm to 2400 nm. Standard schottky electron guns with beam energy up to 10kev we have designed and constructed a low voltage schottky emission gun, whose cathode is immersed in a strong magnetic field. Design and operating experience of triode electron guns. Investigation of beam performance parameters in a pierce.
Lab6 cathode based electron gun 120 khz rf oscillator and power transformer beam extracted in air 5. An electron gun is designed and developed using the pierce configuration for the focusing electrode. Pdf the lab6 cathode has been the brightest thermionic source used in. The gun is capable of delivering a beam current of 500 ma at 50 kv with a beam size of less than 3. In electron microscope applications, these characteristics translate to more beam current in a smaller spot at the sample, improved resolution, and less frequent cathode replacement. Typical design time for a new electron gun for an rf source is 3040 manhours involving 2030 design iterations 1. An ultrabright and monochromatic electron point source. Poisoning of lab6 cathodes received in tinal form 21 february 1977 a a avdienko and m d malev, institute of nuclear physics, novosibirsk 90, ussr this paper describes an investigation of the thermionic emission decay due to chemical interaction between lanthanum hexaboride and the residual gases in. Lab6 cathodes are ideal for many small spot size applications such as sem, tem, sterilization, surface analysis metrology, high current applications such as lithography, xray sources, and even electron beam welders. Gigahertz repetition rate thermionic electron gun concept physical. Some experimental and estimated characteristics of the lab6 rod cathode electron gun. The second main technology of electron sources, originally developed in the 1930s, is based on. Consequently we have chosen single crystal lab6 as the thermionic cathode, which can provide higher current density with good homogeneity electron emission.
Characteristics of electron beams emitted from an electron gun employing 100, 110, and 111 axial orientation lab6 cathodes were investigated over a long period of time. A positive electrical potential is applied to the anode. Study on compact dc electron gun using single crystal cathode of. Electron microscopes utilize an electron source of some kind with the majority using a thermionic gun. This stateoftheart sem, with its highbrightness electron gun system, provides amazing highresolution imaging along with high sensitivity and high spatial resolution analysis at even faster speeds. For the image to form, the electrons that are generated need to be tightly controlled. Kimball physics is a hightech manufacturer of scientific instruments in ultrahighvacuum electron and ion optics. Because of the large number of variables, this is often a time consuming and expensive process. Design and operating experience of triode electron guns arvind jain, a. Laser heated electron beam gun optimization to improve.
A novel numerical calculation method for electron guns volume 32 issue 3 y. Products include microwave components, antennas,and plasmas to high speed digital system and accelerators. The prominent point of this dc electron gun has no grid which would degrade beam emittance. In ems, the condenser aperture is used to exclude electrons emitted at high angles from the electron gun, which will decrease the brightness but improve the quality of the illumination because these peripheral electrons are less coherent, especially in lab 6 and w tungsten guns.
However, a fundamental impediment with all thermionic. The instruments of the evo family combine high performance scanning electron microscopy with an intuitive, userfriendly experience. Simulation of coulomb interaction effects in electron sources. It is necessary to know the basic principles of light optics in order to understand the fundamentals of electron microscopy. Its services unit provides development and design, simulation,measurement and education. Pdf download available kimball physics lanthanum hexaboride lab6. Design and performace of a 30 kv electron gun with ten.
A thermionic electron gun is a triode gun 3 electrode gun functions in the following manner. This is for designs that can be modelled in two dimensions. The h9500 is a 100300 kv tem with an lab6 electron gun. The gun is a thermionic type electron gun with indirect heating of the lab6 cathode.
Investigation of beam performance parameters in a piercetype electron gun ashraf a. Aptech is a top producer of lab6 cathodes lanthanum hexaboride. Depending on the sharpness of the tip, this electron gun exhibits 510 times higher brightness and a 10 times longer lifetime than a tungsten. A history of scanning electron microscopy developments. The emissivity is calculated from scanning monochromator. It is usually a vshaped filament made of lab6 or w tungsten that is. Lab6 cathode vendors many recommend pressures to be in the 8 mbar range. The beam generated by the electron gun goes through the linac and is then accelerated and stored in the booster for a time long enough that the 6d beam phasespace distribution is fully defined by the characteristics of the booster.
172 194 890 601 1458 1090 1451 618 1309 179 1291 57 1423 76 1351 1350 867 955 1334 1254 1143 1009 1003 482 958 651 1261 678 267 275 960 775 738 1259 396 48 218 489 886 968 1339