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Michael G. Ury

Bio: Michael G. Ury is an academic researcher from United States Department of the Navy. The author has contributed to research in topics: Electron & Magnetic field. The author has an hindex of 2, co-authored 3 publications receiving 93 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, a new electron beam injection gun was developed to produce pulsed relativistic electron beams with a power of 1010 W. The annular shaped beam propagates in a magnetic field with efficiencies approaching 100% and its radius may be controlled by the magnetic field configuration.
Abstract: A new electron beam injection gun has been developed to produce pulsed relativistic electron beams with a power of 1010 W. The annular shaped beam propagates in a magnetic field with efficiencies approaching 100% and its radius may be controlled by the magnetic field configuration.

73 citations

Journal ArticleDOI
TL;DR: In this article, a preliminary study was performed to ascertain the feasibility of delivering large quantities of electrical energy in relativistic electron beams of long pulse duration, and an electron beam of 8 kA peak current and 250 kV peak voltage was produced with a duration of ≳1 μsec.
Abstract: A preliminary study was performed to ascertain the feasibility of delivering large quantities of electrical energy in relativistic electron beams of long pulse duration An electron beam of 8 kA peak current and 250 kV peak voltage was produced with a duration of ≳1 μsec The electron beam was transported through a 1 m long drift tube with little energy loss

22 citations

Patent
22 Jun 1977
TL;DR: In this article, a current-reducing device (fuse or switch) is described comprising a foil mber of Al or Mg which is immersed in a fluid with which it will chemically react (such as H2 O or H 2 O2) above a certain temperature.
Abstract: A current-reducing device (fuse or switch) is described comprising a foil mber of Al or Mg which is immersed in a fluid with which it will chemically react (such as H2 O or H2 O2) above a certain temperature. The foil member is an electrical conductor but becomes an electrical insulator as a result of the chemical reaction.

1 citations


Cited by
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Journal ArticleDOI
01 Aug 1976-Nature
TL;DR: In this article, a model of radio sources is proposed in which the magnetized accretion disk of a massive black hole acts as an electric dynamo producing two oppositely-directed beams of ultra-relativistic particles.
Abstract: A model of radio sources is proposed in which the magnetised accretion disk of a massive black hole acts as an electric dynamo producing two oppositely-directed beams of ultra-relativistic particles.

555 citations

Journal ArticleDOI
TL;DR: In this paper, the physics of modulation of an intense relativistic electron beam by an external microwave source via experiment, theory, and simulation is studied via experiment and simulation, and it is found that the self-fields of the electron beam in general intensify the current modulation produced by the external source.
Abstract: The physics of modulation of an intense relativistic electron beam by an external microwave source is studied in this paper via experiment, theory, and simulation. It is found that the self‐fields of the electron beam, in general, intensify the current modulation produced by the external source. The linear and nonlinear theory, together with the simulation, show that the classical klystron description in the drift tube region is substantially modified by the beam’s high density. In the modulating gap, electron bunches may be generated instantaneously without the necessity of propagating the beam through a long drift tube. These properties, which have no counterparts in low‐density beams, lead to the generation of large amplitude, coherent, and monochromatic current modulation on an intense beam. The excellent amplitude stability and the phase‐locking characteristics (<2°) of the modulated current, demonstrated in experiments, open new areas of research in high‐power microwave generation and compact partic...

130 citations

01 Apr 1990
TL;DR: In this paper, the relativistic klystron amplifiers, which are under active study at the Naval Research Laboratory (NRL), are described and compared with the ones used in our experiments.
Abstract: An overview is provided for the novel relativistic klystron amplifiers which are under active study at the Naval Research Laboratory. These amplifiers are driven by an annular intense relativistic electron beam (500-kV, 10-kA range), which is modulated by an external RF source (1.3-GHz, 100-kW range). Experiments, theory, simulation, and simple models are presented to illustrate the unusual properties of such devices which result from the intense space charge of the beam. Chief among them are electrostatic insulation against vacuum breakdown at high power levels, efficient current modulation, short bunching length, and amplitude and phase stability of the output signal. Many of these unexpected features were revealed in two separate experiments: one with a lower current beam (5 kA, 2-cm beam radius), and the other one with a higher current beam (16 kA, 6.6-cm beam radius). Three gigawatts of RF power at 1.3 GHz were generated with the large diameter beam at an efficiency of 35% with 37-dB gain. These experiments are reviewed, along with a combination of particle simulation results and analytic models which facilitate the interpretation. Special attention is paid to the unfamiliar features of these amplifiers, and the critical problems which must be solved before such amplifiers can fulfil their potential in a wide range of applications are addressed. >

66 citations

Journal ArticleDOI
TL;DR: In this article, the relativistic klystron amplifiers, which are under active study at the Naval Research Laboratory (NRL), are described and compared with the ones used in our experiments.
Abstract: An overview is provided for the novel relativistic klystron amplifiers which are under active study at the Naval Research Laboratory. These amplifiers are driven by an annular intense relativistic electron beam (500-kV, 10-kA range), which is modulated by an external RF source (1.3-GHz, 100-kW range). Experiments, theory, simulation, and simple models are presented to illustrate the unusual properties of such devices which result from the intense space charge of the beam. Chief among them are electrostatic insulation against vacuum breakdown at high power levels, efficient current modulation, short bunching length, and amplitude and phase stability of the output signal. Many of these unexpected features were revealed in two separate experiments: one with a lower current beam (5 kA, 2-cm beam radius), and the other one with a higher current beam (16 kA, 6.6-cm beam radius). Three gigawatts of RF power at 1.3 GHz were generated with the large diameter beam at an efficiency of 35% with 37-dB gain. These experiments are reviewed, along with a combination of particle simulation results and analytic models which facilitate the interpretation. Special attention is paid to the unfamiliar features of these amplifiers, and the critical problems which must be solved before such amplifiers can fulfil their potential in a wide range of applications are addressed. >

64 citations

Journal ArticleDOI
TL;DR: In this article, the authors used Bz and B? (z-pinch) fields to guide the beam through a window into the drift region, where the ionization in the drift section allows the beam to be confined by its own magnetic field.
Abstract: Pulsed electron beams are formed by the slow charge of a pulse forming network (microseconds to D. C.) and the fast discharge (10 - 100 ns) onto a field emission diode. The resultant beams of kiloamps to megamps at hundreds of keV to ten MeV are passed through a window into the drift region. Ionization in the drift section allows the beam to be confined by its own magnetic field. Secondary electron currents in the plasma tend to neutralize this effect, Recent work on guiding intense beams with auxiliary fields has utilized applied Bz and B? (z-pinch) fields. Application of these beams extends from shock studies to ion acceleration.

52 citations