| Measurements of Secondary Electron Yield from Materials with Application to Depressed Collectors |
04 APR 2008 |
41 pages |
| Authors:
Edl Schamiloglu; Mark Gilmore; NEW MEXICO UNIV ALBUQUERQUE DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE
|
 | This final technical report reviews the research activities during the period of this grant, emphasizing the final year. The key finding of our study is that the total incident electron dose is a critical parameter affecting secondary electron emission (SEE). A completely automated experimental set-up was implemented that allowed for measurement of secondary electron yield (SEY) as a function of beam energy, angle of incidence of primary electrons, electron dose, ... |
|
| Basic Studies in Plasma Physics |
31 OCT 2007 |
15 pages |
| Authors:
JOEL L. LEBOWITZ; RUTGERS - THE STATE UNIV NEW BRUNSWICK NJ DEPT OF PHYSICS
|
| The primary focus of this three-year basic research effort was to obtain a better understanding of the fundamental physics of electron emission from a variety of surfaces and geometries. The very nature of emission phenomena tends itself perfectly to statistical physics analyses as used herein. The major subtopics addressed (and published) in the course of this grant include the following: space-charge-limited flow of a thin electron beam confined by a ... |
|
| Electron Attachment to SF(6) Under Well Defined Conditions: Comparison of Statistical Modeling Results to Experiments |
Aug-2007 |
14 pages |
| Authors:
Thomas M Miller; Albert A Viggiano; Juergen Troe; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
|
| Experiments were carried out using a flowing-afterglow Langmuir-probe apparatus to measure rate constants for electron attachment to SF6 and thermal detachment from SF6'. In a recent series of papers, these results were combined with new and existing data on nondissociative and dissociative attachment to SF6 and compared to statistical modeling of the various processes involved in the stabilization of the ionic products of attachment. This paper gives a summary of ... |
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| Charge Control of Geosynchronous Spacecraft Using Field Effect Emitters |
JAN 2007 |
13 pages |
| Authors:
M. J. Mandell; V. A. Davis; B. M. Gardner; F. K. Wong; R. C. Adamo; D. L. Cooke; A. T. Wheelock; SCIENCE APPLICATIONS INTERNATIONAL CORP SAN DIEGO CA
|
| *Space Systems Loral is conducting an lR&D program to determine the feasibility and effectiveness of field effect electron emitters for potential control of geosynchronous altitude spacecraft. This electron emitters will be based on Spindt Cathode Field Emission Array Technologies. The configuration studied here consists of two emitters, each with an area of about 1 cm2 and emitting up to 1 mA of electrons at approximately 50eV energy. We show that ... |
|
| Miniature Electron Sources for Tomorrow's Vacuum THz Devices (MiPRI) |
JUL 2006 |
53 pages |
| Authors:
Yuval Carmel; Gregory Nusinovich; John Rodgers; Anatoly Shkvarunets; MARYLAND UNIV COLLEGE PARK INST FOR RESEARCH IN ELECTRONICS AND APPLIED PHYSICS
|
| The most significant experimental accomplishment was the demonstration that plasma-assisted miniature cathodes can generate high perveance electron beams at low voltages (>1000A/sq cm; 0.5-3kV), and that those beams could propagate without external guiding magnetic fields over distances compatible with the length of the RF structure of THz sources. Our theoretical studies showed that this will enable the design of future THz sources operating with relatively high efficiency at high power ... |
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| Stochastic Simulation of Thermoemission from Surfaces of Dusty Grains |
13 JUL 2005 |
5 pages |
| Authors:
A. L. Bondareva; V. D. Levchenko; G. I. Zmievskaya; RUSSIAN ACADEMY OF SCIENCES MOSCOW KELDYSH INST OF APPLIED MATHEMATICS
|
| The thermoemission from dusty grain surfaces is necessary to take into account when processes in dusty plasma are simulated. The thermoemission of electrons can change temperature of electron part of plasma, typical electron velocity and other plasma properties. The kinetic distribution functions of secondary electrons from velocity and distance from dusty grain are calculated. |
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| Space Charge Limited Emission Studies Using Coulomb's Law |
JUN 2004 |
43 pages |
| Authors:
Christopher G. Carr; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Child and Langmuir introduced a solution to space charge limited emission in an infinite area planar diode. The solution follows from starting with Poisson's equation, and requires solving a non-linear differential equation. This approach can also be applied to cylindrical and spherical geometries, but only for one-dimensional cases. By approaching the problem from Coulomb's law and applying the effect of an assumed charge distribution, it is possible to solve for ... |
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| Thermo Field Emission in High Current Arc Discharge |
20-Jul-2003 |
2 pages |
| Authors:
ALL-UNION ELECTRICAL ENGINEERING INST MOSCOW (USSR)
|
| The effect of ion electrical current on the electron thermo field emission from metal surface of cathode in high current arc has been investigated. An electron emission process are considered as follow. One electron emitted due to field of ions in cathode layer is captured by ion to form an exited neutral atom which is then ionized by the electrical field. It is shown that in high current arc random ... |
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| Secondary Electron Emission (SEE) Measurements on Materials Under Stress (Preliminary Measurements of SEE Under High Temperature (Condition) |
23 MAY 2003 |
13 pages |
| Authors:
Shinichi Kobayashi; Yoshio Saito; SAITAMA UNIV SAITAMA-SHI (JAPAN) DEPT OF ELECTRICAL AND ELECTRONIC SYSTEMS
|
| Secondary electron emission (SEE) coefficient of sapphire and Si and energy distributions of secondary electrons from aluminas were measured under high temperature at about 400 degrees C. These measurements intended to establish measurement systems of SEE coefficient and energy analysis of secondary electrons under high temperature conditions. Sample stages of scanning electron microscope (SEM) and X-ray photoelectron spectroscope (XPS) were modified to enable a sample to heat up to a ... |
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| Electron Emitters |
31 JUL 2002 |
70 pages |
| Authors:
Yonhua Tzeng; AUBURN UNIV AL
|
| When two carbon-nanotube coated electrodes are placed at a small distance from each other, electron emission from carbon nanotubes allows a DC or AC electrical current to flow between these two electrodes. The voltage drop across these two electrodes depends on the electric field needed for emitting electrons necessary for carrying electric current and the distance between these two electrodes. This electrical coupler may find applications to high-voltage circuits, which ... |
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| Solid-State Emitter Development |
JUL 2002 |
137 pages |
| Authors:
Marc Cahay; Punit Boolchand; CINCINNATI UNIV OH DEPT OF ELECTRICAL AND COMPUTER ENGINEERING AND COMPUTER SCIENCE
|
| Theoretical and experimental studies were performed to investigate the feasibility of realizing a new, voltage-activated, nonthermionic cathode proposed by Mumford and Cahay (based on W. Friz s concept). It consists of a heavily n-doped indium phosphide (InP) substrate upon which a layer of thin-film cadmium sulfide (CdS) is grown followed by a layer of lanthanum sulfide (LaS) with a metal grid atop it. Theoretically, only a low voltage (<20 volt) ... |
|
| Object-Oriented PIC Code With Upgraded Physics and Platform-Independent GUI |
19 OCT 2001 |
165 pages |
| Authors:
David Bruhwiler; TECH-X CORP BOULDER CO
|
| We have developed a new graphical user interface (GUI) for the particle-in-cell (PIC) code OOPIC, providing a powerful new cross-platform simulation tool for designers of high-power microwave (HPM) devices. Algorithms for modeling the following physical effects have been developed and implemented within the new version of OOPIC: the electron self-force; secondary emission of electrons from metal surfaces; Improved particle loading and injection; improved charge and current deposition for curvilinear grid ... |
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| Materials Data and Theory for Electron Emitters. Design of Wideband Microwave Amplifiers Based on a Combination of Heterojunction Bipolar Transistors, Cold Cathodes, and Coplanar Waveguide Technologies |
AUG 2001 |
36 pages |
| Authors:
Marc Cahay; Kenneth P. Roenker; SYSTRAN FEDERAL CORP DAYTON OH
|
| The objective of this effort is to explore novel design schemes to realize compact wideband microwave amplifiers suited for cold cathode emitter technology. Considerations of a monolithic implementation of an HBT with a cold cathode structure based on several material systems are presented. |
|
| A Method of Making Electron Emitters |
31 JUL 2001 |
26 pages |
| Authors:
Pehr Pehrsson; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A method for fabricating an electron emitter is provided. This emitter structure may be used to form individual emitters or arrays of emitters. The method is comprised of implanting energetic ions into a diamond lattice to form cones or other continuous regions of damaged diamond. These regions are more electrically conducting than the surrounding diamond lattice, and have locally sharp tips at or near the point of entry of the ... |
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| Polarized Electron Photoemission Studies of Spin Relaxation in Thin GaAs Epitaxial Films |
JUN 2001 |
4 pages |
| Authors:
Yuri A. Mamaev; Yuri P. Yashin; Arsen V. Subashiev; Anton N. Ambrajei; Alexander V. Rochansky; SAINT PETERSBURG STATE TECHNICAL UNIV (RUSSIA) LABORATORY OF SPIN-POLARIZED ELECTRON SPECTROSCOPY
|
| The results of systematic study of polarized electron emission from unstrained GaAs thin epitaxial layers with varying thickness are presented. Excitation spectra of the polarized photoemission reflect the optical spin orientation of the electrons produced by the circularly polarized light excitation and spin relaxation kinetics. The interpretation of the spectra and their temperature dependencies shows the importance of valence band wrapping and correlation between the spin and the momentum of ... |
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| Effects of Sulfur Concentration on the Electron Field Emission Properties of Nanocrystalline Carbon Thin Films |
APR 2001 |
6 pages |
| Authors:
S. Gupta; B. R. Weiner; B. L. Weiss; G. Morell; PUERTO RICO UNIV SAN JUAN DEPT OF PHYSICS
|
| The electron field emission properties of sulfur-assisted nanocrystalline carbon (n-C: S) thin films grown on molybdenum substrates by hot-filament CVD technique using methane-hydrogen (CH(4)/H(2)) and hydrogen sulfide-hydrogen (H(2)S/H(2)) gas mixtures were investigated. The field emission properties of the S-assisted films are reported as a function of sulfur concentration. The incorporation of S caused structural and microstructural changes that were characterized with SEM, AFM and Raman spectroscopy (RS). The S-assisted films ... |
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| Field Emission Site Densities of Nanostructured Carbon |
APR 2001 |
5 pages |
| Authors:
J. B. Cui; J. Robertson; W. I. Milne; CAMBRIDGE UNIV (UNITED KINGDOM) DEPT OF ENGINEERING
|
| The field emission properties of nanostructured carbon films deposited by cathodic vacuum arc in a He atmosphere have been studied by measuring the emission currents and the emission site density. The films have an onset field of ^3 V/micrometer. The emission site density is viewed on a phosphor anode and it increases rapidly with applied field. It is assumed that the emission occurs from surface regions with a range of ... |
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| Ballistic Electron Emission Microscopy Study of Novel Quantum Objects and Electronic Defects |
03 AUG 2000 |
23 pages |
| Authors:
Venkatesh Narayanamurti; John Bowers; CALIFORNIA UNIV SANTA BARBARA
|
| Over the approximately 2 1/2 year period of the above AFOSR grant, substantial progress has been made in the further development of Ballistic Electron Emission Microscopy (BEEM) as a quantitative microscopic and spectroscopic tool for the characterization of buried quantum objects and electronic defects in semiconductors. During the period of this grant, we have done the following: Developed a theoretical model for the simulation ... |
|
| Hot-Filament Assisted Fabrication of Carbon Nanotube Electron Emitters |
30 APR 2000 |
7 pages |
| Authors:
Yonhua Tzeng; AUBURN UNIV AL DEPT OF ELECTRICAL ENGINEERING
|
| A hot-filament CVD reactor was used for the deposition of carbon nanotubes on substrates. Hydrocarbon or oxyhydrocarbon mixtures were used as the carbon source. Hot filaments at temperatures exceeding 200 deg C provided a means of dissociating the vapor or gas feedstock, heating the substrate, and allowing gas species to react in the gas phase as well as on the surface of the substrate leading to ... |
|
| Electron Emission from Microwave-Plasma Chemically Vapor Deposited Carbon Nanotubes |
30 APR 2000 |
7 pages |
| Authors:
Yonhua Tzeng; AUBURN UNIV AL DEPT OF ELECTRICAL ENGINEERING
|
| A microwave plasma CVD reactor was used for the deposition of carbon nanotubes on substrates. Hydrocarbon or oxyhydrocarbon mixtures were used as the carbon source. Hot electrons in the microwave plasma at temperatures exceeding 10,000 deg C provided a means of dissociating the vapor or gas feedstock, heating the substrate, and allowing gas species to react in the gas phase as well as on the surface ... |
|
| Non-Cesiated Solid State Electron Emitters (Cold Cathodes) & Their Applications in Vacuum Microelectronics |
31 MAY 1999 |
25 pages |
| Authors:
Umesh K. Mishra; Robert D. Underwood; CALIFORNIA UNIV SANTA BARBARA DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| Stable, non-cesiated cold cathodes hold much promise for high power and high efficiency vacuum electronics. Cesium is typically used to lower the surface barrier to electron emission, but cesium presents problems with reliability and lifetime. GaN-based cold cathodes have the advantage of having a low surface barrier and a stable surface, both of which are beneficial for cold cathode electron emission. Better performance, in terms of ... |
|
| Object-Oriented PIC Code with Upgraded Physics and Platform-Independent GUI |
1999 |
165 pages |
| Authors:
David Bruhwiler; TECH-X CORP BOULDER CO
|
| This report covers the period between June 15, 1999 and September 14, 2001. Detailed technical information on the research described is not presented here, but can be found in attached reports and journal publications and in portions of the recent text edited by R.J. Barker and E. Schamiloglu. Many of the algorithms discussed here have been implemented in the XOOPIC code, which is freely available for noncommercial use thus, providing ... |
|
| Interface Engineering and Defect Control in Heteroepitaxial Growth of GaN |
SEP 1998 |
53 pages |
| Authors:
Robert J. Nemanich; Harald W. Ade; Robert F. Davis; NORTH CAROLINA STATE UNIV AT RALEIGH
|
| The technique of photo electron emission microscopy (PEEM) combined with UV free electron laser (UV-FEL) excitation has been employed for in situ studies of the dynamics of semiconductor interfaces. Wide bandgap semiconductors such as diamond, GaN and AlN exhibit a small or even negative electron affinity. The PEEM results show a shift of the photo threshold or in situ annealed diamond surfaces consistent with an increase in the ... |
|
| Secondary and Backscatter Electron Emission from Conductors |
JUL 1998 |
162 pages |
| Authors:
Warren G. Wilson; AIR FORCE RESEARCH LAB KIRTLAND AFB NMSPACE VEHICLES DIRECTORATE
|
| Reports the absolute secondary and backscatter electron yield cross section ?#/#! tor copper, aluminum, and carbon targets as a function of incident electron energy and angle. Reports the energy distribution of the secondary and backscatter electron as a function of emission angle ?#/(%.ev.sr) for the same target set. |
|
| Transport in Single Atomic Junctions: Strong Correlation and Coulomb Blockade |
JUN 1998 |
2 pages |
| Authors:
F. Yamaguchi; D. H. Huang; Y. Yamamoto; STANFORD UNIV CA EDWARD L GINZTON LAB OF PHYSICS
|
| We report here the first observation of the strong correlation and Coulomb blockade effects in a single-atomic junction (single tungsten-atom STM tip). In contrast to previous work the use of an atomic-scale central island makes the change in the electrostatic potential due to the variation of the number of electrons in the island greater than 1eV and thus the electron correlation effect is made more controllable and stable even at ... |
|
| High Resolution Studies of Thin Film Interfaces |
02 MAR 98 |
11 pages |
| Authors:
R. A. Buhrman; CORNELL UNIV ITHACA NY
|
| This research program was generally concerned with the application of Ballistic Electron Emission Microscopy (BEEM) and related scanning tunneling microscopy (STM) techniques to the study of interfacial ballistic transport in a range of electronic materials, and with the extension of BEEM to locally examine aspects, consequences, and possible applications of elastic and inelastic electronic scattering processes at both Schottky barrier interfaces and thin film overlayers. |
|
| Spontaneous Emission in Microcavity Lasers |
DEC 97 |
119 pages |
| Authors:
Dustin Philip Ziegler; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH
|
| An understanding of spontaneous emission processes within microcavities is crucial in addressing the need to make tomorrow's microlasers more efficient. One approach to improving the device efficiency is to reduce the threshold input energy at which lasing begins to occur. It has been suggested that the threshold in a microcavity laser can be decreased by increasing the fraction of spontaneous emission into the lasing mode, this can be accomplished by ... |
|
| Ballistic Electron Emission Spectroscopy Study of Transport through Semiconductor Quantum Wells and Quantum Dots |
01 SEP 97 |
15 pages |
| Authors:
Venkatesh Narayanamurti; CALIFORNIA UNIV SANTA BARBARA
|
| This report summarizes the development and use of Ballistic Electron Emission Microscopy (BEEM) for nondestructive, local characterization of semiconductor heterostructures under AFOSR grant No. F49620-94-1-0378. The technique has been applied for measuring heterojunction band offsets, for studying band structure effects in electron tunneling through double barrier resonant tunneling structures, and for imaging current flow through buried mesoscopic structures such as quantum dots (approx. 10nm in size) and misfit dislocations 80nm ... |
|
| Growth, Characterization and Device Development in Monocrystalline Diamond Films |
SEP 97 |
19 pages |
| Authors:
R. F. Davis; R. J. Nemanich; Z. Sitar; P. K. Baumann; B. L. McCarson; NORTH CAROLINA STATE UNIV AT RALEIGH
|
| Photoemission and field emission from p-type natural diamond crystals are dependent on the surface termination. Hydrogen termination results in a negative electron affinity (NEA) while O and adsorbate-free surfaces exhibit positive electron affinities. Thin metal layers can induce an effective NEA which can be modeled in terms of the metal workfunction and the metal-diamond Schottky barrier. NEA surfaces of p-type diamond are shown to exhibit emission with lower voltages. Nitrogen-doped ... |
|
| Use of Ballistic-Electron-Emission Microscopy to Study Mechanisms for Long Wavelength Schottky-Barrier Infrared Detectors |
JUL 97 |
48 pages |
| Authors:
Leo J. Schowalter; RENSSELAER POLYTECHNIC INST TROY NY
|
| In this final report, we have summarized our work in five areas. The first area, covered in Sec. I, is the development of calcium fluoride tunnel barriers which may be used to increase the operating temperature of PtSi SBIRDs. In particular, we have demonstrated a new technique for growth of exactly two monolayers of CaF2 on Si(l 11) substrates. In Sec. II, we describe our work with ballistic electron emission ... |
|
| Light-BEEM Technology: A Local Probe of Metal Semiconductor Interfaces |
13 JUN 1997 |
6 pages |
| Authors:
Dror Sarid; ARIZONA UNIV TUCSON OPTICAL SCIENCES CENTER
|
| This final report describes an experimental system aimed studying a novel characterization method of metal-semiconductor interfaces which combines ballistic electron emission microscopy (BEEM) with optical excitations. The idea is that the spreading resistance, or space charge, associated with the ballistic electrons injected into the Schottky barrier by the tip of a scanning tunneling microscope (STM), can be modulated by optical excitation. The local photoresponse can therefore be mapped spatially across ... |
|
| Low Voltage Electron Beam Lithography |
JUN 95 |
3 pages |
| Authors:
Weidong Liu; STANFORD UNIV CA CENTER FOR INTEGRATED SYSTEMS
|
|
| Low Temperature Materials Growth and Processing Development for Flat Panel Display Technology Applications |
MAY 95 |
15 pages |
| Authors:
C. N. Berglund; OREGON GRADUATE INST BEAVERTON
|
| A thin catalyst film of nickel (0.4 nm thick) on a silicon substrate was reduced in hydrogen at 875 deg C for 30 minutes. Carbon nanotubes were subsequently grown at 950-1000 deg C in less than 5 minutes. A more uniform electron emission was obtained in the vacuum testing station, compared to previous nanotube preparation techniques. Also the Fowler-Nordheim plots were more reproducible. |
|
| Semiconductor Cold Electron Emission Device. |
02 AUG 1994 |
|
| Authors:
Max N. Yoder; DEPARTMENT OF THE NAVY WASHINGTON DC
|
 | A semiconductor cold electron emission device comprising a type I heterojunction formed of a P-type semiconductor mixture of AIN and a N-type semiconductor mixture of SiC which junction is forward biased so that electrons are monoenergetically emitted from the P-type semiconductor mixture. |
|
| BEEM 94. Annual Workshop on Ballistic Electron Emission Microscopy (5th) Held in New York on January 24, 1994 |
24 JAN 94 |
44 pages |
| Authors:
CALIFORNIA UNIV SANTA BARBARA
|
| Partial contents: Electron transport across interfaces and surfaces: an overview; BEEM studies of strain-tuned semiconductor interfaces; Transport studies in semiconductor heterostructures using BEEM; Spectroscopic studies of quantum-wells and -wires using an STM; BEEM in pinholes of NiS2 films on n- Si(111)-7x7: determination of the impact ionization quantum yield in Si; Low- temperature UHV BEEM of epitaxial CoSi2/Si(111); Interfacial barrier studies of epitaxial CoGa on n-type (100) GaAs with BEEM; BEEM ... |
|
| International Free Electron Laser Conference (15th) Held in The Hague, Netherland on August 23-27, 1993 |
27 AUG 93 |
290 pages |
| Authors:
FOM-INST VOOR PLASMAFYSICA RIJNHUIZEN (NETHERLANDS)
|
|
| Field Emitter Array Memory Device. |
27 JUL 1993 |
|
| Authors:
Henry F. Gray; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A field emitter array memory device having two or more collector electrodes, an extraction electrode, at least one deflector electrode, and at least one electron field emitter is disclosed. The field emitter array memory circuit has bias voltages for collector electrodes, for the at least one deflector electrode and for the extraction electrode. In a preferred embodiment of the invention, first and second input signal voltages selectively applied to first ... |
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| Thin-Film Edge Field Emitter Device and Method of Manufacture Therefore. |
31 MAR 1993 |
|
| Authors:
Henry F. Gray; David S. Hsu; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| It is therefore an object of the present invention to provide a field emitter device which substantially eliminates the need for the use of high spatial resolution lithography in its fabrication. It is another object of the present invention to provide a field emitter device having inherent advantages over previous electron sources, including higher emission currents, lower power requirements, less expensive fabrication costs and ease of integration with other circuitry. ... |
|
| Dissociation Rates of Diatomic Molecules |
DEC 92 |
233 pages |
| Authors:
Philip C. Cosby; Hanspeter Helm; SRI INTERNATIONAL MENLO PARK CA
|
| Absolute cross sections were measured for the electron-impact dissociation of simple molecules using a novel fast beam technique with multicoincident detection of the dissociation fragments. Translational energy released in the dissociation and product mass ratios were explicitly measured, allowing a detailed understanding of the dissociation mechanisms. The technique was applied to the molecules of nitrogen, oxygen, carbon monoxide, carbon dioxide, nitrogen dioxide, chlorine, and other molecules. A detailed description of ... |
|
| Regulatable Field Emitter Device and Method of Production Thereof. |
30 JUL 1992 |
|
| Authors:
Henry F. Gray; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A voltage controlled current source such as a field effect transistor is provided to output a regulated current in dependence upon a control voltage. An electron field emitter is connected to a drain or output of the voltage controlled current source to receive the regulated current. A tip of the electron field emitter emits electrons towards a collector anode. An extractor gate can be provided between the electron field emitter ... |
|
| Electron Emission by Nanosecond Switching in PLZT, |
05 APR 1991 |
|
| Authors:
Hartmut Gundel; TECHNISCHE UNIV BERLIN (GERMANY F R)
|
| Copious electron emission from a PLZT ceramic surface takes place either when the surface is illuminated with laser pulses, or when short high-voltage pulses are applied. In the latter case, charge densities of up to 5 micron C/cm2 and current densities of some ten of amperes per square centimetre have been measured. Depending on the. position of the material in its phase diagram, different behaviour of the emission has been ... |
|
| A Collection of Selected Papers from the Third All-China Electroemissions Technology Conference (Selected Pages) |
21 MAR 91 |
85 pages |
| Authors:
FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH
|
|
| The Fabrication and Characteristics of Ta sub 2 N Field Emitters |
20 SEP 90 |
22 pages |
| Authors:
Xiang-qi Jiang; Takeo Kato; FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH
|
| The electron beam emission elements used in micro-manufacturing are made more and more important with the rapid advancement of electronic components and devices. Furthermore, the development of scanning electron microscopes with high resolution also promote the study of high intensity electron beam sources. At present, the mechanism of field emission of tungsten has been studied extensively and the results have been applied to many practical situations. However, the work function ... |
|
| Plasma-Anode Electron Gun Research |
30 MAY 89 |
61 pages |
| Authors:
Robert W. Schumacher; Joseph Santoru; HUGHES RESEARCH LABS MALIBU CA
|
| The plasma-anode electron gun (PAG) is a new cold-cathode electron source which exhibits many novel features. These include instant starting, no cathode heater power, minimal vacuum requirements, a nonpoisoning cathode, long- pulse operation without gap closure, and beam modulation at ground potential with constant beam energy. The basic concept involves a collective interaction between counterpropagating streams of electrons and ions in a high-voltage diode gap. A Pierce electron-gun configuration is ... |
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| Hot Electron Emission in Semiconductors |
25 MAR 88 |
|
| Authors:
Erich Gornik; Karl Unterrainer; Manfred Helm; INNSBRUCK UNIV (AUSTRIA) INST OF EXPERIMENTAL PHYSICS
|
| The spectrum of the simulated far infrared emission from p-Germanium in crossed electric and magnetic fields is studied by means of a tunable narrow- band GaAs-detector. A multimode spectrum is observed from polished high parallel samples. The mode spectrum is quantitatively explained in terms of internal waveguide-like modes. With the help of an external resonator the number of modes was drastically reduced. The external resonator has a confocal configuration. For ... |
|
| Modulatable Thin Film Field Emission Space Gun |
NOV 87 |
|
| Authors:
Robert M. Phillips; STAR MICROWAVE CAMPBELL CA
|
| The objective of this research program was to determine the feasibility of using a Spindt type thin film emitter chip to produce amperes of low voltage modulated current at tens of kilovolt beam voltage for a space application. The specific requirement was for a pulse modulated column of electrons of 10 amperes current at 50 kilovolts voltage. A design effort determined that a 2-inch diameter chip would be required to ... |
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| Secondary Electron Generation, Emission and Transport: Effects on Spacecraft Charging and NASCAP Models, |
MAY 1987 |
|
| Authors:
Ira Katz; Myron Mandell; James C. Roche; Carolyn Purvis; S-CUBED LA JOLLA CA
|
| Secondary electron phenomena play an important role in many aspects of spacecraft charging. This paper discusses three distinct cases that show: 1)A good formulation for the secondary electron yield as a function of incident electron energy is needed in order to determine whether a given particle spectrum will cause strong negative charging for a given spacecraft material; 2) Suppression of secondary electron emission by electric fields plays a dominant role ... |
|
| Three Dimensional Modelling and Numerical Analysis of Super-Radiant Harmonic Emission in FEL (Optical Klystron) |
01 SEP 1986 |
32 pages |
| Authors:
A. Gover; A. Friedman; A. Luccio; BROOKHAVEN NATIONAL LAB UPTON NY NATIONAL SYNCHROTRON LIGHT SOURCE
|
| A full 3-D Analysis of super-radiant (bunched electron) free electron harmonic radiation is presented. A generalized form of the FEL pendulum equation was derived and numerically solved. Both spectral and phasor formulation were developed to treat the radiation in the time domain. In space the radiation field is expanded in terms of either a set of free space discrete modes or plane waves. The numerical solutions reveal some new distinctly ... |
|
| Hot Electron Emission in Semiconductors |
30 JUN 86 |
|
| Authors:
E. Gornik; Robert Christanell; Manfred Helm; Karl Unterrainer; INNSBRUCK UNIV (AUSTRIA) INST OF EXPERIMENTAL PHYSICS
|
| Sub micron sinusoidal gratings were prepared on GaAs/GaAlAs heterostructures. Experiments to demonstrate a Smith-Purcell-effect in a semiconductor are in preparation. FIR emission due to streaming of hot carriers in crossed electric and magnetic fields has been observed on large p-Ge samples. Stimulated emission has not been achieved yet. A new theory of the crossed field configuration (electric and magnetic) describing the Landau levels in a quantum mechanical manner was developed. ... |
|
| Explosive Emission Cathode Plasmas in Intense Relativistic Electron Beam Diodes |
30 JAN 85 |
215 pages |
| Authors:
D. Hinshelwood; JAYCOR ALEXANDRIA VA
|
| An experimental study of cathode plasmas in planar diodes driven by a Sandia Nereus accelerator (270 kV, 60 kA, 70 ns), with particular attention devoted to plasma uniformity and expansion velocity, has been carried out. This diode current density was varied over a factor of ten and the rate of rise of the applied field dE/dt was varied over a factor of six. Different cathode materials, coatings, and surface roughnesses ... |
|
Reports by Keyword(s)
*ELECTRON EMISSION
