Abstract:
A microwave magnetron includes a cathode for emitting electrons, a filament for receiving a filament current to heat the cathode to enable to cathode to emit the electrons, and an anode to which anodic power can be applied to affect a flow of the electrons. An anodic power input receives the anodic power to be applied to the anode, the anodic power being characterized by an anodic current, an anodic voltage, and an anodic impedance, the anodic impedance being a quotient of the anodic voltage and the anodic current. An electromagnet power input receives electromagnet power and applies the electromagnet power to an electromagnet to control an intensity of a magnetic field, the electromagnet power being characterized by an electromagnet current. A controller adjusts at least one of the parameters of the magnetron to affect the flow of electrons while maintaining the anodic impedance constant.
Abstract:
In a leading-in arrangement of cathode leads (85, 86) connecting with the cathode filament (68) which is placed along the center line of an evacuated external case (50) forming part of a cylindrical anode (51) of a magnetron, a magnet pole (77) has a vertical hole (75) along the center line and a horizontal hole (76) connected at right angles with the vertical hole and the cathode leads are taken in through these holes. By means of this leading-in arrangement a cylindrical permanent magnet (73) made from a material of alnicos is located in a magnetic circuit. The cylindrical anode (51) consists of a moulded member having cylindrical parts of smaller (54) and greater (55) diameters. An output (64) and an input (65) are attached to the side of the cylindrical part with the greater. If, as preferred, the permanent magnets (71, 73) are placed in hollows on the outside of the case and furthermore are placed in inside the yokes (72, 74) for the magnetic circuit, a magnetic force can be obtained inside the case while the magnets themselves are located outside.
Abstract:
A free electron laser comprising: an electron source, a linear accelerator, an undulator, electron beam optics and a deceleration unit. The electron source is operable to produce a bunched electron beam. The linear accelerator arranged to impart energy to electrons in the bunched electron beam produced by the electron source. The undulator is operable to produce a periodic magnetic field and is arranged so as to guide the bunched electron beam along a periodic path about a central axis of the undulator such that the electrons interact with radiation in the undulator, stimulating emission of coherent radiation. The electron beam optics is arranged to direct the bunched electron beam back into the linear accelerator after it leaves the undulator so as to extract energy from electrons in the bunched electron beam. An electron beam separator separates the decelerated electron beam from the accelerated electron beam. The electron beam separator comprises a magnet system operable to generate a separator magnetic field, the separator magnetic field having a field direction that is perpendicular to the first direction and a field strength that increases in a second direction away from a point of entry of the decelerated electron beam into the separator magnetic field, the second direction being perpendicular to the field direction and at an acute angle to the first direction.
Abstract:
A high pressure arc discharge lamp (10) includes a sealed envelope (12); a pair of spaced electrodes (20 and 22) in the envelope; an ionizable medium (16) in the envelope for generating a plasma arc (18) between the electrodes; and a magnetic field source (40) for generating a magnetic field for suppressing plasma jet instability (24) emanating from the plasma arc.
Abstract:
Vacuum electron devices (VEDs) are produced having a plurality of two-dimensional layers of various materials that are bonded together to form one or more VEDs simultaneously. The two-dimensional material layers are machined to include features needed for device operation so that when assembled and bonded into a three-dimensional structure, three-dimensional features are formed. The two-dimensional layers are bonded together using brazing, diffusion bonding, assisted diffusion bonding, solid state bonding, cold welding, ultrasonic welding, and the like. The manufacturing process enables incorporation of metallic, magnetic, and ceramic materials required for VED fabrication while maintaining required positional accuracy and multiple devices per batch capability. The VEDs so produced include a combination of magnetic and electrostatic lenses for electron beam control.
Abstract:
Cost-effective, simple, low-noise, crossed-field devices such as a microwave magnetron, a microwave oven utilizing same, and crossed-field amplifier utilize an azimuthally varying, axial magnetic field. The magnetic configuration reduces and eliminates microwave and radio frequency noise. This microwave noise is present near the carrier frequency and as sidebands, far separated from the carrier. The device utilizes azimuthally-varying, axial, magnetic field perturbations. At least one permanent perturbing magnet having an azimuthally-varying magnetic field impressed thereupon causes the axial magnetic field to vary azimuthally in the magnetron and completely eliminates the microwave noise and unwanted frequencies. Preferably, the number of axial magnetic field perturbations is based on the number of cavities of the magnetron.
Abstract:
Embodiments of the present disclosure generally provide magnetron configurations that provide more efficient and/or more uniform cooling characteristics and methods for forming the magnetrons. The magnetron includes one or more flow directing structures disposed between parallel cooling fins. The flow directing structures direct air flow across various surfaces of the cooling fins and prevent that otherwise would be obstructed by magnetron components, reducing the incidence and/or magnitude of hot spots on the cooling fins and/or on other magnetron components. The flow directing structures also adjust flow rates to improve cooling efficiency.