Design considerations for a high voltage DC photoemission electron gun at Cornell University

2010 ◽  
Author(s):  
Bruce M. Dunham ◽  
Karl W. Smolenski
Keyword(s):  
High Voltage ◽  
Electron Gun ◽  
Cornell University ◽  
Design Considerations ◽  
Photoemission Electron

scholarly journals High voltage performance of a dc photoemission electron gun with centrifugal barrel-polished electrodes

2017 ◽  
Vol 88 (9) ◽  
pp. 093303 ◽  
Author(s):  
C. Hernandez-Garcia ◽  
D. Bullard ◽  
F. Hannon ◽  
Y. Wang ◽  
M. Poelker
Keyword(s):  
High Voltage ◽  
Electron Gun ◽  
Voltage Performance ◽  
Photoemission Electron

100 KV Scanning Microscope

1972 ◽  
Vol 30 ◽  
pp. 472-473 ◽  
Author(s):  
A. V. Crewe ◽  
M. W. Retsky
Keyword(s):  
High Voltage ◽  
Voltage Divider ◽  
Electron Gun ◽  
Objective Lens ◽  
Parallel Beam ◽  
Emission Point ◽  
Error Amplifier ◽  
External Reference ◽  
Scanning Transmission ◽  
Transmission Microscope

A 100 kv scanning transmission microscope has been built. Briefly, the design is as follows: The electron gun consists of a field emission point and a 3 cm Butler gun. The beam has a crossover outside the gun and is collimated by a condenser lens.The parallel beam passes through a defining aperture and is focused by the objective lens onto the specimen. The elastic electrons are detected by two annular detectors, each subtending a different angle, and the unscattered and inelastic electrons are collected by a third detector. The spectrometer that will separate the inelastic and unscattered electrons has not yet been built.The lens current supplies are stable to within one part per million per hour and have been described elsewhere.The high voltage is also stable to 1 ppm/hr. It consists of the raw supply from a 100 kv Spellman power supply controlled by an external reference voltage, high voltage divider, and error amplifier.

A New High Intensity Grid Cap for RCA-EMU-3 Electron Microscopes

1968 ◽  
Vol 26 ◽  
pp. 316-317
Author(s):  
George Christov ◽  
Bolivar J. Lloyd
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
High Voltage ◽  
High Intensity ◽  
Electron Gun ◽  
Tungsten Filament ◽  
Fluorescent Screen ◽  
Electron Microscopes ◽  
Pass Through ◽  
Ground Potential

A new high intensity grid cap has been designed for the RCA-EMU-3 electron microscope. Various parameters of the new grid cap were investigated to determine its characteristics. The increase in illumination produced provides ease of focusing on the fluorescent screen at magnifications from 1500 to 50,000 times using an accelerating voltage of 50 KV.The EMU-3 type electron gun assembly consists of a V-shaped tungsten filament for a cathode with a thin metal threaded cathode shield and an anode with a central aperture to permit the beam to course the length of the column. The cathode shield is negatively biased at a potential of several hundred volts with respect to the filament. The electron beam is formed by electrons emitted from the tip of the filament which pass through an aperture of 0.1 inch diameter in the cap and then it is accelerated by the negative high voltage through a 0.625 inch diameter aperture in the anode which is at ground potential.

DESIGN CONSIDERATIONS OF HIGH VOLTAGE BATTERY PACKS FOR ELECTRIC BUSES

2017 ◽  
Author(s):  
MEHMET UĞRAŞ CUMA ◽  
EMRAH YİRİK ◽  
ÇAĞLA DERİCİOĞLU ◽  
ERDEM ÜNAL ◽  
BURAK ONUR ◽  
...  
Keyword(s):  
High Voltage ◽  
Design Considerations ◽  
Battery Packs ◽  
High Voltage Battery

Design considerations and experimental analysis of high-voltage SiC Schottky barrier rectifiers

1998 ◽  
Vol 45 (7) ◽  
pp. 1595-1604 ◽  
Author(s):  
K.P. Schoen ◽  
J.M. Woodall ◽  
J.A. Cooper ◽  
M.R. Melloch
Keyword(s):  
Schottky Barrier ◽  
High Voltage ◽  
Experimental Analysis ◽  
Design Considerations

Design Considerations of Packaging a High Voltage Current Switch

2015 ◽  
Author(s):  
Ankan De ◽  
Adam Morgan ◽  
Subhashish Bhattacharya ◽  
Douglas C. Hopkins
Keyword(s):  
High Voltage ◽  
Power Devices ◽  
Variable Parameters ◽  
Package Design ◽  
Current Switch ◽  
Density Distributions ◽  
Design Considerations ◽  
Parasitic Parameters ◽  
Electric Potentials ◽  
Switch Design

In this paper an attempt has been made to demonstrate various package design considerations to accommodate series connection of high voltage Si-IGBT (6500V/25A die) and SiC-Diode (6500V/25A die). The effects of connecting the cathode of the series diode to the collector of the IGBT versus connecting the emitter of the IGBT to the anode of the series diode has been analyzed in regards to gate terminal operation and the parasitic line inductance of the structure. ANSYS Q3D/MAXWELL software have been used to analyze and extract parasitic inductance and capacitances in the package along with electromagnetic fields, electric potentials, and current density distributions throughout the package for variable parameters. SIMPLIS-SIMETRIX is used to simulate typical switch behavior for different parasitic parameters under hard switched conditions. Various simulation results have then been used to redesign and justify the optimized package structure for the final current switch design. The thermal behavior of such a package is also conducted in COMSOL in order to ensure that the thermal ratings of the power devices is not exceeded, and to understand where potentially harmful hotspots could arise and estimate the maximum attainable frequency of operation. The main motivation of this work is to enumerate detailed design considerations for packing a high voltage current switch package.

Sign in / Sign up

Export Citation Format

Share Document