Current density limitations in a fast-pulsed high-voltage vacuum diode

  • 56 Pages
  • 0.36 MB
  • English
Naval Postgraduate School, Available from the National Technical Information Service , Monterey, Calif, Springfield, Va
Statementby D.S. Welsh
ContributionsSchwirzke, Fred R.
The Physical Object
Pagination56 p. ;
ID Numbers
Open LibraryOL25524251M

Calhoun: The NPS Institutional Archive Theses and Dissertations Thesis Collection Current density limitations in a fast-pulsed high-voltage vacuum diode Abstract. Approved for public release: distribution is investigation into the limitations on the enhanced field-emitted current density in a fast-pulsed (rise-time = ns), high voltage (> V), 1-inch vacuum diode was conducted using a computer simulation based on the Fowler-Nordheim :// High current density is generally a less degrading condition than low current density due to the reduced cell voltage.

However, high current density operation is generally at higher temperature due to increased heat production, resulting in increased degradation rates (see Section ).The following are areas of concern: • Increased operating temperature will accelerate membrane and The mechanism by which plasma forms in a fast pulsed high vacuum diode has been greatly studied.

Details Current density limitations in a fast-pulsed high-voltage vacuum diode EPUB

For the most part, efforts have been concentrated on plasma formation at the cathode. Recently, investigators improved the popular explosive emission model, taking into account the ion current density and surface heating through ion bombardment. This model provides total current densities of the .3W/abstract.

current density limitations in a fast-pulsed high-voltage vacuum diode 12 personal author(s) david s. welsh 13a type of report btime covered i1 date of report (year, month. day) p age count master's thesis ifrom to june i63 This is an up-to-date review of studies in the physics of pulsed electrical discharges in a vacuum.

It gives the reader detailed information on the processes occurring at electrodes and in vacuum gaps and on the mechanisms of discharge initiation and development.

Modern techniques and equipment are described in detail. Their high temporal and spatial resolution may be used to solve a number of Pulsed electrical discharge in vacuum G.A. Mesyats, D.I. Proskurovsky (Springer series on atoms + plasmas, 5) Springer-Verlag, c us: gw:   Figure (a) Fast: response photodiode is used to detect the on-set of the optical trigger.

Description Current density limitations in a fast-pulsed high-voltage vacuum diode FB2

The time difference between the optical trigger (solid curve) and the beginning of the current flowing (dotted curve) is defined as the switch delay. The photodiode signal distortion is caused by the high voltage pulse noising,~muggli/PDFs/MPPTheses/pdf.

P-n diode performance limitations. 2 Switching processes in p-n diodes are relatively slow V s V d R I Schottky diode has the same type of current - voltage dependence as a p-n diode: SCH S exp 1 qV II The current density is larger near the contact Schottky & Ohmic The basic difference between this vacuum arc and cold cathode arcs is the lower average cathode current density.

Because of this lower current density, distributed arcs do not exhibit the high frequency oscillations in discharge voltage and chaotic cathode spot motion characteristic of An investigation into the limitations on the enhanced field-emitted current density in a fast-pulsed Current density limitations in a fast-pulsed high-voltage vacuum diode book on the order of ns), high voltage (greater than 10(exp 6) V), 1-inch vacuum diode   current), V0is the voltage across the diode junction, q is the charge of an electron, k is Boltzmann's constant, and T is the temperature in degrees Kelvin.

Two significant features to note from both the curve and the equation are that the photogenerated current (Ip)is additive to the diode current, and the dark current is High-power critical electron emission from dielectric induced by injection of high-current-density electron beam Vaisburd, D.

/ Tverdokhlebov, S. / Tukhfatulin, T. | digital version print version:CN/Fast-Ionization-Dynistor-FID-A-New. In order to evaluate the device performance under high current density pulsed operation, 2-D models of SiC p-i-n, Schottky, and JBS diodes rated for kV BV and A/cm² current density were   Abstract.

The Child-Langmuir (CL) flow in a planar diode in the presence of stationary charged dust particles is studied. The limiting electron current density and other diode properties, such as the electrostatic potential, the electron flow speed, and the electron number density   arXiv:physics/v3 [-ph] 11 Jan The Physics of high-intensity high-energy Particle Beam Propagation in open Air and outer-space Plasmas Andre Gsponer Independent Scientific Research Institute Gunn Diode.

The diodes are classified into different types based on their working principles and characteristics. These include Generic diode, Schotty diode, Shockley diode, Constant-current diode, Zener diode, Light emitting diode, Photodiode, Tunnel diode, Varactor, Vacuum tube, Laser diode, PIN diode, Peltier diode, Gunn diode, and so a special case, this article discuss about Gunn A high-voltage (HV) pulse generator, an upgrade of the device used in ref.

[25], supplies a 1 GV/m acceleration gradient across the 2 mm acceleration gap of this diode. To avoid breakdown of the   ADAPTIVE HIGH VOLTAGE PULSE SIGNAL GENERATOR CIRCUIT DESIGN A Thesis Presented by Lixi Tao to The Faculty of the Graduate College of The University of Vermont In Partial Fulfillment of the Requirements for the Degree of Master of Science Specializing in Electrical Engineering October, Defense Date: Thesis Examination Committee:?article=&context=graddis.

• Switching speed varies from very fast (ns) to slow(’s µs) • Limited in peak power capability. High voltage requires series stacks and high peak current requires parallel arrays. • Usually high average current capability (compared with thyratrons) •   NAVAL POSTGRADUATE SCHOOL Monterey, California AD-A THESIS TIME RESOLVED MEASUREMENTS OF LIGHT PRODUCED BY ONSET OF PLASMA FORMATION ON ELECTRODES OF FAST PULSED HIGH VOLTAGE DIODES by Charles M.

Wright December, Thesis Advisor: F. Schwirzke Thesis Co-advisor: X. Maruyama Approved for public release; @article{osti_, title = {Determining the mode of high voltage breakdowns in vacuum devices}, author = {Miller, H C and Furno, E J and Sturtz, J P}, abstractNote = {Devices were constructed which were essentially vacuum diodes equipped with windows allowing observation of high voltage breakdowns.

The waveform of the applied voltage was photographed, and the x-ray output was monitored to The present paper extends the prior findings on self-induced heating of solid state field emission devices. It was found that a vacuum diode (base pressure ~10 −9 Torr), that makes use of graphite-rich polycrystalline diamond as cathode material, can switch from a diode regime to a resistor regime to a glow discharge plasma regime without any external perturbation, i.e.

all transitions are   DC Diode Sputtering Deposition Substrate (Anode) 2 – 5kV e-Target (Cathode) e- - γ ArAr + • Target (source) and substrate are placed on two parallel electrodes (diode) • They are placed inside a chamber filled with inert gas (Ar) • DC voltage (~ kV) is applied to the diode • Free electron in the chamber are accelerated by the e-field chenFabrication II - Deposition.

The Insulated Gate Bipolar Transistor (IGBT) is a minority-carrier device with high input impedance and large bipolar current-carrying capability. Many designers view IGBT as a device with MOS input characteristics and bipolar output characteristic that is a voltage-controlled bipolar device.

To make use of the advantages of both Power   Electron tube - Electron tube - Common tubes and their applications: Many types of electron tubes are involved in RF electric power generation and amplification.

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Another class of electron tubes is employed for rectification and switching (thyratrons and ignitrons). Some vacuum and gas tubes are designed merely to illuminate a target, as in the case of a television :// Concrete surface scraping with high voltage pulsed power generator EG Egorov, I.

S., Kanaev, G. G., Kukhta, V. R., Dynamics of cathode plasma speed in planar diode with explosive emission cathode Pushkarev, A. I Using of dosimetric film for analysis of energy density distribution of a high-current pulsed electron beam Ezhov, VV The key component of such systems is the vacuum switch, which is to stay closed for a long enough time to charge an inductor with current and to open on a fast time scale to produce a power amplified output pulse near the final vacuum load.

The development of such a vacuum device, called the “reflex switch”, is described :// PASOTRONs have been developed in xenon, helium and hydrogen plasmas delivering 1–5 MW of power of pulse duration > μs with 15–20% efficiency in L, C, S and X bands, using a plasma cathode current density of PCE guns up to 50– A cm −2 and 30 A–1 kA beam current and 30– kV accelerating voltage.

Also, PASOTRONs are capable The Electromagnetic gun (EMG) system needs a compact pulsed power supply system, which should supply high energy and large current. The paper presents a setup of a compact pulsed power supply system used for EMG system, which is based on high energy density capacitors.

The pulse forming network consist of ten 50 kJ modules, which can be triggered in ://. High beam current. High beam current, and therefore current density, is desirable.

This gives rise to higher photon flux, and hence shorter detector integration times, in addition to improved signal-to-noise ratios. Combined with the use of gate control to pulse the X-ray source, high beam currents can be very advantageous to system ://High Pressure Pulsed Radial Glow Discharge CO 2 Laser William M.

Moeny Proc. SPIEPulse Power for Lasers II, pg (10 April ); doi: /The high conductivity of current bipolar devices is combined with limitations of the switch­ing speed. The maximum current density is usually not limited by the semiconductor but by heat removal. New packaging concepts seem to allow an improvement of surge-current capability and average on