Download or read book Field Emission Electronics written by Nikolay Egorov and published by Springer. This book was released on 2017-06-01 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is dedicated to field emission electronics, a promising field at the interface between “classic” vacuum electronics and nanotechnology. In addition to theoretical models, it includes detailed descriptions of experimental and research techniques and production technologies for different types of field emitters based on various construction principles. It particularly focuses on research into and production of field cathodes and electron guns using recently developed nanomaterials and carbon nanotubes. Further, it discusses the applications of field emission cathodes in new technologies such as light sources, flat screens, microwave and X-ray devices.

Download or read book Applied Research on Field Emission Cathodes written by E. E. Martin and published by . This book was released on 1963 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effort was directed toward the study of field emission cathodes and their development to a practical electron source. Primary emphasis was on relatively gross structures for use at high power levels. Emission currents to 22 amperes at 390 kilovolts were obtained from single, needle-shaped, tungsten emitters and to 105 amperes at 203 kilovolts from an edge-shaped, tungsten structure. Point cathodes were shown to emit maximum currents in agreement with theoretical prediction based on energy exchange at the cathode and on cathode dimensions. Electrolytic and chemical techniques were developed for fabrication of edge cathodes which were free of cold work and had terminal radii of the order of 0.00001 cm. Electron optical systems appropriate for use with field emitted beams were studied; and basic knowledge of the behavior of adsorbates which improve beam utility by selective emission enhancement in the forward direction was extended. (Author).

Download or read book Research on Field Emission Cathodes written by E.E. Marin and published by . This book was released on 1959 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Research on Field Emission Cathodes written by E.E. Marin and published by . This book was released on 1960 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Formation and Characteristics of a Broad area Semiconductor Field Emission Cathode written by John W. Hanson and published by . This book was released on 1969 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work is a study of the formation, operation and application of a semiconductor field emission cathode consisting of one or more individual emitting points on a broad area cathode. The material primarily used was germanium. Two methods of forming these cathodes were studied; a vacuum breakdown method and one using radiation from a pulsed ruby laser focused on the cathode surface. The former is the method by which the cathode was first revealed. The latter holds the most promise for making cathodes practical. Both types of cathodes were observed with a scanning electron microscope to aid in understanding the mechanism by which the very regular emitting points are formed. The electrical characteristics of the cathode were studied experimentally and found to agree with theory of semiconductor field emission. A retarding potential analyzer was designed and built to measure the energy distribution for electrons emitted from individual points on the cathode. An electron optical system was used to study the operation of the semiconductor cathode as an electron source for such applications as in a cathode ray tube or similar device requiring a low-current electron beam. (Author).

Download or read book Field Emission in Vacuum Microelectronics written by George N. Fursey and published by Springer Science & Business Media. This book was released on 2007-12-24 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Field emission is a phenomenon described by quantum mechanics. Its emission capability is millions times higher than that of any other known types of electron emission. Nowadays this phenomenon is experiencing a new life due to wonderful applications in the atomic resolution microscopy, in electronic holography, and in the vacuum micro- and nanoelectronics in general. The main field emission properties, and some most remarkable experimental facts and applications, are described in this book.

Download or read book A Novel Emission Electron Microscope for the Study of Field Emission Cathodes and Their Emittance written by Daniel Enderich and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vacuum electronic devices (VEDs) serve an important role as high-power and/or high-frequency sources of RF radiation. To access higher power and higher frequency regimes, VEDs will require greater current densities and lower emittance electron beams. Field emission cathodes show tremendous promise in satisfying these needs, but much remains to be learned about how the cathode structure affects the emittance of the resulting beam. Some theoretical work has been published, but no experimental data has been produced to guide and validate these theoretical developments. In this dissertation, I motivate the need for a better understanding of these cathodes for application in VEDs. I show why emittance is such an important figure of merit for electron beams and how it relates to the beam current density. I demonstrate that the only way to acquire the data necessary to test the recent theoretical developments regarding emittance is to construct a focusing field emission electron microscope (f-FEEM) capable of resolving individual emission sites with large magnification. I provide design guidelines for constructing such an f-FEEM, and I present initial test data validating its performance. Finally, I propose future research directions that will improve the performance of the f-FEEM and open up new areas of research.

Download or read book A Study of Field emission Cathodes for Selected High power Tubes written by BATTELLE MEMORIAL INST COLUMBUS OHIO. and published by . This book was released on 1961 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results are presented of a one-month study of the U.S. research, development, and application activities on field-emission (FE) cathodes for microwave power tubes, millimeter-wave tubes, and high-power switch tubes. The increasing demands imposed on high-power microwave tubes, millimeter-wave tubes, and high-power switch tubes have necessitated continuing efforts toACHIEVE IMPROVEMENTS IN HIGH-CURRENT-DENSITY CATHODES AND HIGH-INTENSITY, ELECTRON-BEAM GENERATION METHODS. The use of Fe cathodes represents one approach which has been investigated in an attempt to solve the high-current-density cathode problem. The study was based significantly on information obtained by searching the published literature and available reports, and by personally discussing various aspects of the problem with people associated with the U.S. electron-tube industry. During the period, 25 companies and universities were contacted; their names and those of the individuals involved at each organization are listed. (Author).

Download or read book Research in Field Emission and Its Application written by W. W. Dolan and published by . This book was released on 1957 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fundamental Research on Raw Materials Used for Electron Emissivity on Indirectly Heated Cathodes written by United States. Office of Naval Research and published by . This book was released on 1947 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Soviet Research in Field Electron and Ion Emission 1955 1959 written by Tibor W. Marton and published by . This book was released on 1960 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soviet field emission research, as reflected in the technical literature from 1955 through 1959, is the subject matter of this annotated bibliography. Topics include experimental and theoretical work on field electron emission from metals and semiconductors, work functions, phase transformations, absorption, diffusion, evaporation, surface ionization, and field ion emission. Over one hundred complete references and to a few in Polish, Hungarian, and Czech were selected after an extensive search of the literature. Full references are given to English translations of the entries whenever available. A list of relevant scientific meetings, references, and a brief subject index are appended to the compilation.

Download or read book Soviet Research in Field Emission 1960 1963 written by Tibor W. Marton and published by . This book was released on 1964 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soviet field emission research, including both the experimental and theoretical aspects of field electron and ion emission from metals and semiconductors, is the subject of this bibliography.Over 80 complete references to original publications and 50 meeting papers were selected after an extensive search of the Soviet and East European technical literature published from January 1960 through November 1963.Most of these papers are in Russian; a few are in Czech, English, Hungarian, Polish, and Ukrainian.Full references are given to English translations of the entries whenever available.A list of relevant scientific meetings, papers read at these meetings, bibliographic references, and a brief subject index are appended to the compilation.This bibliography represents the continuation of the survey published in October 1960 as U.S. NBS Technical Note 75.(Author).

Download or read book Modern Developments in Vacuum Electron Sources written by Georg Gaertner and published by Springer Nature. This book was released on 2020-10-09 with total page 609 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives an overview of modern cathodes and electron emitters for vacuum tubes and vacuum electron devices in general. It covers the latest developments in field emission theory as well as new methods towards improving thermionic and cold cathodes. It addresses thermionic cathodes, such as oxide cathodes, impregnated and scandate cathodes, as well as photocathodes and field emitters – the latter comprising carbon nanotubes, graphene and Spindt-type emitter arrays. Despite the rise and fall of the once dominant types of vacuum tubes, such as radio valves and cathode ray tubes, cathodes are continually being improved upon as new applications with increased demands arise, for example in electron beam lithography, high-power and high-frequency microwave tubes, terahertz imaging and electron sources for accelerators. Written by 17 experts in the field, the book presents the latest developments in cathodes needed for these applications, discussing the state of the art and addressing future trends.

Download or read book Interim Technical Report on High Density Field Emission Beams and Field Emission from Semiconductors written by and published by . This book was released on 1960 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nanostructured Carbon Electron Emitters and Their Applications written by Yahachi Saito and published by CRC Press. This book was released on 2022-01-27 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon forms a variety of allotropes due to the diverse hybridization of s- and p-electron orbitals, including the time-honored graphite and diamond as well as new forms such as C60 fullerene, nanotubes, graphene, and carbyne. The new family of carbon isotopes—fullerene, nanotubes, graphene, and carbyne—is called “nanostructured carbon” or “nanocarbon.” These isotopes exhibit extreme properties such as ultrahigh mechanical strength, ultrahigh charge–carrier mobility, and high thermal conductivity, attracting considerable attention for their electronic and mechanical applications as well as for exploring new physics and chemistry in the field of basic materials science. Electron sources are important in a wide range of areas, from basic physics and scientific instruments to medical and industrial applications. Carbon nanotubes (CNTs) and graphene behave as excellent electron-field emitters owing to their exceptional properties and offer several benefits compared to traditional cathodes. Field emission (FE) produces very intense electron currents from a small surface area with a narrow energy spread, providing a highly coherent electron beam—a combination that not only provides us with the brightest electron sources but also explores a new field of electron beam–related research. This book presents the enthusiastic research and development of CNT-based FE devices and focuses on the fundamental aspects of FE from nanocarbon materials, including CNTs and graphene, and the latest research findings related to it. It discusses applications of FE to X-ray and UV generation and reviews electron sources in vacuum electronic devices and space thrusters. Finally, it reports on the new forms of carbon produced via FE from CNT.

Download or read book Advancing Field Emission Technology for High Power Injectors Operating in Ghz and Beyond written by Mitchell E. Schneider and published by . This book was released on 2022 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the next generation of electron injectors pushes to achieve higher gradient fields than ever before (>300 MV/m), they are driven to operate at higher frequencies (C-band through W-band). This shrinks the fabrication dimensions of these cavities, making field emission cathodes (FECs) an electron source of choice. Photoemission and thermionic sources are increasingly less suited as the complex laser transport schemes and heating source powering these injectors cannot provide the necessary beam quality and may cause damage to the cathode or the injector itself. Carbon-based FECs have dominated the field emission sources R&D portfolio at DOD and DOE for the past 30 years across various high-power vacuum electronic device activities. Compared to traditional metal cathode technology, carbon-based technology cathodes are able to produce higher charge at low electric fields. Small intrinsic electron momentum and simple fabrication means these can become a leading technology, e.g., in the case of carbon nanotubes, nanoscale emitters make them attractive for producing high brightness beams. Specifically, diamond-based cathodes can handle extreme temperature and mechanical stresses that can occur under high gradient conditions.Most promising is a unique form of diamond, ultra-nano-crystalline diamond (UNCD) due to its material and electrical properties, which include being the most conductive form of diamond due to having the largest amount of grain boundaries. This cathode material allows us to explore new frontiers of cathode physics research, revealing a new field emission mechanism that diverges from classical Fowler Nordheim, termed space charge dominated Fowler Nordheim. This form of Fowler Nordheim is space charge dominated but can surpass the 1D Child Langmuir limit and approaches the 2D limit. This is not space charge limited Fowler Nordheim. This ability to decouple the extracted current from the space charge effects allows for the production of extremely bright beams. This can be achieved by expanding the current cathode testing facilities beyond L band into C band so as to access these high fields and explore the temporal dynamics of a field emission source. This will yield the new physics knowledge needed to construct the world's first custom-built injector specifically designed for field emission sources.Furthermore, exploring other forms of diamond cathode such as Diamond Field Emitter Arrays (DFEA) yields insight into the applications of transversely shaped beams for advanced accelerator applications such as emittance exchange beam lines. DFEA's allow for the exploration of additional materials effects on the cathode performance such as the ballast resistance. This ultimately allows the derivation of a comprehensive concept map for the field emission dynamic regimes needed for the design of RF injectors. Previously, the theoretical assumption was that everything operated under classical Fowler Nordheim without any additional contributions from other materials properties or beam effects.

Download or read book Soviet Development of Needle tip Field emission Cathodes for High current Electron Beams written by Simon Kassel and published by . This book was released on 1973 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: The paper summarizes recent Soviet theoretical and experimental work on cathodes for very high-current charged particle beams. Field emission from needle-tip cathodes is based on explosive emission from the tips, accompanied by explosion-derived plasma setting up intense local electric fields. A cathode fabrication method is described that gives stable operation through 10,000 to 100,000 pulses of about 3 nanoseconds each, for currents of 500 to 1000 A.A liquid cathode produces stable current pulses within 6 percent of 2000 A. In a large needle array, 80 percent to 100 percent of the tips maintained current value dispersion within 20 percent. Operational cathodes of the controllable tip-and-dielectric type have been developed for 500 keV and 50 kA, and of the multiple-tip types for 1 MeV and 50 kA.