Abstract: The utilization of heat in the manufacturing of footwear may be accomplished through microwave energy. The microwave energy is conveyed to the footwear components through a microwave transparent window of a tool. The microwave transparent tool window forms as least a portion of a part-contacting surface of the tool. Another surface of the tool is formed from a microwave reflecting material, such as aluminum. The footwear component(s) are exposed to microwave energy while within the tool such that the microwave energy passes through the tool window to cause a dielectric heating of one or more materials within a tool cavity of the tool.

Abstract: System and method for temperature-calibration of a crystal oscillator (XO) in a mobile device. A temperature-calibration status of the XO is determined and a trigger condition related to temperature-calibration of the XO is detected. If the temperature-calibration status of the XO is not fully temperature-calibrated or if the XO has not been previously temperature-calibrated, a temperature-calibration session is initiated by an XO manager based on the condition, wherein a receiver is configured to receive signals and temperature-calibration of the XO is performed in a background mode based on the received signals. The condition based triggering ensures that the XO is temperature-calibrated prior to launch of any position based or global navigation satellite systems (GNSS) based applications on the mobile device.

Abstract: Aspects of the subject disclosure may include, an access point that facilitates receiving from a system a modulated signal in a first spectral segment, wherein the system is configured to receive a plurality of ultra-wideband electromagnetic waves via a transmission medium and extract the modulated signal in the first spectral segment from a plurality of modulated signals conveyed by the plurality of ultra-wideband electromagnetic waves, and wherein the plurality of ultra-wideband electromagnetic waves operates in a second spectral segment that differs from the first spectral segment, and transmitting the modulated signal in the first spectral segment to a communication device. Other embodiments are disclosed.

Abstract: A high-energy radiation treatment system can comprise a laser-driven accelerator system, a patient monitoring system, and a control system. The laser-driven accelerator system, such as a laser-driven plasma accelerator or a laser-driven dielectric microstructure accelerator, can be constructed to irradiate a patient disposed on a patient support. The patient monitoring system can be configured to detect and track a location or movement of a treatment volume within the patient. The control system can be configured to control the laser-driven accelerator system responsively to the location or movement of the treatment volume. The system can also include a beam control system, which generates a magnetic field that can affect the radiation beam and/or secondary electrons produced by the irradiation beam. In some embodiments, the beam control system and the patient monitoring system can comprise a magnetic resonance imaging system.

Abstract: A method for producing electromagnetic radiation comprising: firing a first laser pulse and generating a plasma region, the first laser pulse penetrating at least partially into the plasma region to create a plasma density wake in the plasma region; providing a group of charged particles in the plasma region arranged so as to be accelerated in the plasma density wake of the first laser pulse; reflecting the first laser pulse after the first laser pulse has penetrated into the plasma region, to give a reflected laser pulse; and arranging the reflected laser pulse to interact with the group of charged particles to generate an electromagnetic radiation.

Abstract: A measuring whispering-gallery-mode resonator includes: a dielectric resonating body with a rotation axis, a superconducting sample under test mounted to the resonating body and a coupling unit for coupling a measuring waveguide with the resonating body. One side of the resonating body connected with the coupling unit has a first endplate, in which m coupling holes penetrate through the first endplate, and centers of the m coupling holes are arranged to be evenly spaced along a circle whose center is on the rotation axis. The coupling unit has a feeder line which is a coaxial waveguide, and an axis of the coaxial waveguide coincides with the rotation axis. One end surface of the coaxial waveguide, which is perpendicular to the rotation axis, abuts the first endplate; and the azimuth index of operated whispering gallery mode in the resonator is an integer multiple of the number m of the coupling holes.

Abstract: An RF resonator cavity for accelerating charged particles is provided, wherein an electromagnetic RF field can be coupled into the RF resonator cavity. During operation, the RF field acts on a particle beam which traverses the RF resonator cavity. At least one intermediate electrode for increasing the dielectric strength is arranged in the RF resonator cavity along the beam path of the particle beam, wherein the conductivity of the intermediate electrode is limited such that upon coupling-in of the electromagnetic RF field at the operating frequency of the RF resonator cavity the intermediate electrode is at least partially penetrated by the coupled-in electromagnetic RF field.

Abstract: A device for imparting an orbital angular momentum to a charged particle wave propagating along a beam axis in a charged particle beam generating apparatus is described. The device comprises a support element having a target region adapted for transmitting a charged particle wave propagating along a beam axis and an induction means for inducing a magnetic flux along an elongated profile having a free end portion located in the target region and the induction means is adapted for providing a magnetic flux in the elongated profile in order to induce an angular gradient, relative to the beam axis, of the phase of the charged particle wave when transmitted through the target region. A corresponding method is also disclosed, as well as the use thereof in electron microscopy.

Abstract: An electrode of an inductive output tube (IOT) is provided with channels for guiding cooling fluid. In one aspect of the invention, the channels are in a confronting relationship with a jacket surrounding the electrode and spaced from the electrode so as to define an interior region. Cooling fluid such as oil is circulated in the channels in fluid communication with the interior region, providing an escape mechanism for trapped bubbles in order to prevent localized heating of the electrode. In another aspect of the invention, the channels form multiple intersecting helical patterns of different pitches, with the steeper-pitched channels providing a more direct escape route for the bubbles.

Abstract: A mode-selective interactive structure for gyrotrons includes a plurality of metal tubes, wherein an inner wall of each metal tube forms a waveguide; and between each adjacent pair of the metal tubes exists a slice with a first interface and a second interface and when an electromagnetic wave comprising an operating mode and a competing mode propagates through the slice, the competing mode is partially reflected upon, partially transmitted through and/or absorbed at the first interface and the second interface of the slice so that the power loss of the competing mode is larger than the operating mode and the production of the competing modes is suppressed progressively thereby achieving mode selection.

Abstract: A coaxial cavity gyrotron with two electron beams includes an electron gun (magnetron injection gun, “MIG,” with two beams), a coaxial beam-wave interaction cavity and an outer magnetic field tube. The coaxial beam-wave interaction cavity consists of two parts: an outer conductor and an inner conductor. The two hollow electron beams produced by the MIG are located between the outer conductor and the inner conductor. The MIG includes inner and outer anodes, with a single cathode located between the anodes. The cathode further includes two emitter rings which produce the two hollow electron beams. The entire gyrotron is immersed in the magnetic field tube such that the magnetic field profile is the same or similar to that for a coaxial gyrotron with one electron beam.

Abstract: A mode-selective interactive structure for gyrotrons includes a plurality of metal tubes, wherein an inner wall of each metal tube forms a waveguide; and between each adjacent pair of the metal tubes exists a slice with a first interface and a second interface and when an electromagnetic wave comprising an operating mode and a competing mode propagates through the slice, the competing mode is partially reflected upon, partially transmitted through and/or absorbed at the first interface and the second interface of the slice so that the power loss of the competing mode is larger than the operating mode and the production of the competing modes is suppressed progressively thereby achieving mode selection.

Abstract: An output window for a vacuum electron device comprises an output waveguide, an intermediate layer of dielectric material joined to the interior of the output waveguide with a vacuum-tight seal, and upper and lower layers of dielectric material spaced apart from the intermediate layer and arranged above and below, respectively, the intermediate layer in a vertical orientation of the output waveguide. The upper and lower layers including openings. Supports extend inwardly into the output waveguide and support the upper and lower layers. Pillars extend through the openings in the lower layer and support the intermediate layer. The openings in the upper and lower layers permit a venting of a region between the upper layer and the intermediate layer and a region between the lower layer and the intermediate layer during the sealing of the intermediate layer while the intermediate layer is supported by the pillars.

Abstract: The invention relates to a microwave power tube consisting of an electron gun comprising a cathode that generates an electron beam in a microwave structure of the tube, and a collector for collecting electrons from the beam. In addition, the tube comprises a magnetic device for spreading the beam in the collector, which generates a periodic amplitude-modulated magnetic spread field Bblm. The invention is suitable for microwave power tubes.

Abstract: A method and apparatus for accelerating charged particles are disclosed, wherein the method comprises using at least a transverse component of a temporally and spatially shaped electromagnetic field to accelerate one or more charged particles.

Abstract: In a channel spark source triggered by gas discharge for generating a stable focused electron beam, a gas supply for a hollow cathode thereof is provided which generates in the hollow cathode a pressure differential so that the multiplication of charge carriers in a trigger plasma of a trigger plasma source connected to the hollow cathode provides for a reliable gas discharge and the formation of a stable electron beam which exits the arrangement and which does not damage the internal passages of the arrangement.

Abstract: An inductive output tube (IOT) operates in a frequency range above 1000 MHz. An output window may be provided to separate a vacuum portion of the IOT from an atmospheric pressure portion of the IOT, the output window being surrounded by a cooling air manifold, the manifold including an air input port and a plurality of apertures permitting cooling air to move from the port, through the manifold and into the atmospheric pressure portion of the IOT. The output cavity may include a liquid coolant input port; a lower circular coolant channel coupled to receive liquid coolant from the liquid coolant input port; a vertical coolant channel coupled to receive liquid coolant from the lower circular coolant channel; an upper circular coolant channel coupled to receive liquid coolant from the vertical coolant channel; and a liquid coolant exhaust port coupled to receive liquid coolant from the upper circular coolant channel.

Abstract: A varnish composition, an inductive core made with the varnish composition, and methods of making the varnish composition and the core. The varnish composition includes an acrylic copolymer compound, a cosolvent having at least one of amine and amide functionality, and water. The varnish composition yields high bond strength when there are extended air dry periods prior to curing.

Abstract: In an inner conductor of a coaxial gyrotron, which inner conductor is disposed on the cathode of the gyrotron and includes an entrance funnel, a center part and an exit funnel, axial corrugations are formed in the conductor by axial grooves formed into its wall such that they begin at the end of the entrance funnel and have, in the center part, an increasing depths up to the exit funnel, in which the depth again becomes steadily smaller, the corrugations being evenly distributed about the inner circumference of the inner conductor.

Abstract: A coupled cavity circuit for a microwave electron tube comprises at least two resonant cavities adjacent to each other. An electron beam tunnel passes through the coupled cavity circuit to allow a beam of electrons to pass through and interact with the electromagnetic energy in the cavities. An iris connecting the adjacent cavities allows electromagnetic energy to flow from one cavity to the next. The iris is shaped to cause the iris mode passband to be lower in frequency than the cavity mode passband while still providing broadband frequency response. In addition, the present coupled cavity circuit operates on an electron beam to interact with the third space harmonic of the second passband (the cavity passband) of the electromagnetic signal. Preferably, this interaction occurs on the second passband as this operational design provides output with higher frequencies without decreasing the cavity size. Furthermore, this operational design provides more frequencies with no increase to the iris size.

Abstract: A wiggler that, when used in a free electron laser, reduces the harmonicity of the light emitted from the free electron laser. In general, the reduced harmonicity is accomplished by making the magnetic field distribution of the wiggler to be sinusoidal, rather than like a square wave. The sinusoidal magnetic field distribution reduces the number of harmonics that can be used to approximate the magnetic field distribution of the wiggler, and thus reduces the harmonicity of the light produced by passing an electron beam through the wiggler. In a particular embodiment, the wiggler is composed of pieces or segments of permanent magnets that are arranged along an axis such that their magnetic orientations are perpendicular to the axis, and such that the magnetic field distribution along the axis is sinusoidal.

Abstract: Disclosed is a novel hybrid wiggler as a kind of insertion devices, for example, in an electron accelerator. Different from a conventional hybrid wiggler consisting of two oppositely facing arrays each formed of an alternate arrangement of a plurality of permanent magnet blocks and a plurality of pole pieces of a soft magnetic material to generate a sine-curved periodical magnetic field in the gap space between the arrays to cause meandering of electron beams, each of the pole pieces is sandwiched on the lateral surfaces with a pair of auxiliary permanent magnet blocks so that the periodical magnetic field generated in the gap space can be greatly strengthened.

Abstract: A vacuum electron device with a photonic bandgap structure that provides the ability to tune the behavior of the device to a particular mode of a plurality of modes of propagation. The photonic bandgap structure comprises a plurality of members, at least one of which is movable, and at least one of which is temperature controlled. The photonic bandgap structure makes possible the selection of one mode of propagation without the necessity to build structures having dimensions comparable to the wavelength of the propagation mode.

Abstract: In a substantially circular waveguide constituting a mode converter in a gyrotron tube, there is a region whose transverse inner surface shape changes to a non-true circular shape from a true circular shape in a range of 0 mm to 5 mm toward a radiation aperture from the incident side. Therefore, an undesirable cavity resonator which causes parasitic oscillation can be prevented from being formed in the vicinity of an inlet of the mode converter. Therefore, the parasitic oscillation of the mode converter can be suppressed, and a conversion efficiency of the converter can be enhanced, because of the effective length of the mode converter can be enhanced in the limited actual length.

Abstract: An electromagnetic wave amplifier and an electromagnetic wave generator operate using electron beams in a vacuum environment. The amplifier, arranged in a vacuum environment, comprises an electron emitting section for emitting electron beams and an amplifying section for amplifying an inputted electromagnetic wave in one direction by utilizing energy received from an electron beam emitted from the electron emitting section and traveling in the vacuum along a dielectric waveguide having a wave-shaped form. The generator, also arranged in a vacuum environment, comprises an electron emitting section for emitting electron beams and an oscillating section for generating an electromagnetic wave by utilizing electron beams emitted from the electron emitting section and travelling in the vacuum along a dielectric waveguide having a composite wave-shaped form.

Abstract: A toroidal magnet structure for polarizing a magnetic wiggler and a synchrotron normal is provided. This structure comprises a toroid composed of a plurality of magic ring semicircular segments, with an equatorial slot extending about a periphery of the toroid. The toroid further comprises a central hollow core and a toroidal axis perpendicular to the toroid. The magic ring semicircular segments are wedge-shaped to prevent magnetic flux leakage between segments and to form a continuous toroid. The equatorial slot allows emission of radiation outside the toroid. An electron beam means injects an electron beam into the central hollow core. The magnetic field thus created has a vertical component Bv within the central hollow core and a periodic horizontal component Bh, alternating in direction from ring to ring. The vertical component Bv keeps the electron beam in a generally circular electron path around the toroid and is constant along the entire path.

Abstract: A system and method for increasing the power density distribution uniformity of a gyrotron radiation beam provides a mirror for reflecting the gyrotron beam onto an object to be irradiated, where the shape of the mirror surface is changed by a plurality of controllable and movable mirror support members in a chaotic or random manner during generation of the gyrotron beam on the mirror surface, and the shape of the mirror surface is changed at a predetermined frequency F according to a predefined algorithm.

Abstract: A method for generating a closely spaced train of extremely high voltage short pulses. The method involves generating the train of pulses by combining a plurality of harmonic amplitudes to construct said pulses, via a Fourier construction. Any arbitrary pulse shape can be reproduced simply by changing the amplitude of the harmonics. The train of high voltage electrical pulses produced by the method of the present invention is particularly well suited for the acceleration of particles by applying the pulses to an appropriate accelerating structure, or the pulses can be used to drive an undulator/wiggler.

Abstract: In a substantially circular waveguide constituting a mode converter in a gyrotron tube, there is a region whose transverse inner surface shape changes to a non-true circular shape from a true circular shape in a range of 0 mm to 5 mm toward a radiation aperture from the incident side. Therefore, an undesirable cavity resonator which causes parasitic oscillation can be prevented from being formed in the vicinity of an inlet of the mode converter. Therefore, the parasitic oscillation of the mode converter can be suppressed, and a conversion efficiency of the converter can be enhanced, because of the effective length of the mode converter can be enhanced in the limited actual length.

Abstract: A TEM resonator RF coil with excellent operating characteristics comprising a plurality of ring segments on the orifice capable of being segmented by slits on the orifice are installed with a first conducting pattern connecting to the line element, a second conducting pattern disposed symmetrically on the left and right of the first conducting pattern, a capacitor connecting these conducting patterns, and a connection means spanning the adjacent ring segments and connecting the second conducting patterns.

Abstract: A device for damaging electronic equipment has a millimeter wave generator, such as a gyrotron oscillator, for producing very high power millimeter waves. A beam former antenna forms the millimeter waves into narrow beams for distance transmission. An antenna coupled to the gyrotron directs narrow beams of the millimeter waves to selected targets, whereby the beams damage electronic equipment at the targets. The millimeter wave generator produces frequencies ranging from about 100 to 140 GHz at 20 millisecond megawatt pulses at 400 kilowatts CW.

Abstract: A spherical magnet structure having a cavity centrally disposed therein at an axis therethrough, is constructed to distribute a magnetic field in the cavity with the magnitude thereof varying periodically over a circular pattern in a plane passing perpendicular through the axis. Such construction is accomplished with magnet segments of melon wedge configurations which are fabricated and arranged in accordance with the periodic distribution desired for the field. A source of wiggler radiation is derived by combining that magnet structure with means for introducing charged particles into the field which directs the travel thereof around the circular pattern in a periodic path thereacross.

Abstract: A spherical magnet structure having an axis about which an equatorial gap disposed into the periphery thereof, is constructed to sustain a magnetic field across the gap with the field magnitude varying periodically over a circular pattern in a plane passing perpendicularly through the axis. Such construction includes magnet segments which are configured and aligned across the gap in wedge-shaped arrangements to sustain magnetic field contributions thereacross. A source of wiggler radiation is derived by combining the magnet structure with means for introducing charged particles into the gap thereof, wherein the field influences the particles to travel circularly in a continuous periodic path.

Abstract: In a gyrotron comprising a cathode with an emitter ring, an accelerating anode, a resonator, a collector, and an uncoupling conduit, an arrangement is disposed around the resonator which generates a solenoidal static axial magnetic constant field which, in the area of the resonator, assumes a predetermined wave form causing the electrons emitted from the cathode to move along a spiral path and which has varying localized strengths such that the electrons passing therethrough along the spiral path have, upon exiting the resonator area, only an insignificant transverse velocity component left, whereupon they are attracted by the collector which is precharged.

Abstract: An inductive output tetrode includes a cylindrical ceramic envelope within which is located an electron gun including a cathode and grid. An annular resonant input cavity into which a high frequency signal is coupled surrounds the envelope and is located adjacent the electron gun so as to provide a modulating electric field in the cathode-grid region to density modulate the electron beam. The input cavity is connected to two metal cylinders arranged immediately adjacent to the outside of the envelope. Metallic portions located within the envelope are co-extensive with cylinders with the material of the envelope 1 being located between them. These structures act as r.f. chokes to reduce high frequency losses from the input cavity. Tuning of the resonant cavity may be achieved by adjusting a tuning member which is at distance of quarter of a wavelength at the resonant frequency from the cathode-grid region.

Abstract: An electromagnetic radiation amplification device comprising an electron gun for introducing a stream of electrons into an electron drift tube/wavequide in which an axial magnetic field and a wiggler magnetic field have been induced to impart a helical gyration to the electrons as they travel parallel to the tube. The axial, or guide, magnetic field is directed in the direction opposite to the direction of propagation of the electrons if the electrons have a right handed helical gyration and is directed in the direction of propagation of the electrons if the electrons have a left handed helical gyration.

Abstract: A microwiggler assembly produces large magnetic fields for oscillating ched particle beams, particularly electron beams for free electron laser (FEL) application. A tube of electrically conductive material is formed with radial slots axially spaced at the period of the electron beam. The slots have alternate 180.degree. relationships and are formed to a maximum depth of 0.6 to 0.7 times the tube circumference. An optimum slot depth is selected to eliminate magnetic quadrupole fields within the microwiggler as determined from a conventional pulsed wire technique. Suitable slot configurations include single slits, double slits, triple slits, and elliptical slots. An axial electron beam direction is maintained by experimentally placing end slits adjacent entrance and exit portions of the assembly, where the end slit depth is determined by use of the pulsed wire technique outside the tube.

Abstract: The invention discloses a wiggler used in synchrotron radiation sources and free electron lasers, where each pole is surrounded by at least two electromagnetic coils. The electromagnetic coils are energized with different amounts of current to provide a wide tunable range of the on-axis magnetic flux density, while preventing magnetic saturation of the poles.

Abstract: In a quasi-optical gyrotron, two coils (3a, 3b) in a Helmholtz arrangement generrate a static magnetic field aligned parallel to an electron beam axis (2). As a result, the electrons passing along the electron beam axis (2) parallel to the magnetic field are forced into gyration and excite an alternating electromagnetic field in a quasi-optical resonator. The resonator comprises two mirrors (4a, 4b) arranged opposite to one another on a resonator axis (5). The resonator axis (5) is aligned perpendicularly to the electron beam axis (2) between the two coils (3a, 3b). The mirrors exhibit a mutual distance which is much greater than one half wavelength of the electromagnetic radiation. To generate a wideband radiation, at least one mirror, (4b) is moved at a high frequency by at least about one half wavelength of the electromagnetic radiation by a vibrator (10).

Abstract: Conversion from a whispering gallery or volume mode to a more useable mode, such as the HE.sub.1,1 mode is achieved in a waveguide mode converter that includes input and output sections. The input section includes overlapping circular and coaxial waveguides. Microwave energy in a whispering gallery or volume mode within the circular waveguide is coupled through an array of N equally spaced axial slots placed in the common wall separating the circular waveguide and the coaxial waveguide to coaxial TE and TM modes. Helical grooves placed in one of walls of the coaxial waveguide convert the coaxial mode to a quasi parallel plate mode wherein the common wall separating the inner circular waveguide from the outer coaxial waveguide functions as one plate, and the outer wall of the coaxial waveguide functions as the other plate. The quasi parallel plate mode propagates microwave energy spirally through the coaxial waveguide in a direction k, where k makes an angle .theta. to the waveguide axis.

Abstract: In a gyrotron cavity resonator, generated energy is extracted into a symmetric set of fundamental-mode waveguides by ports disposed to couple energy in phase from the operating electromagnetic mode but in anti-phase with respect to an unwanted mode of lower cutoff frequency than the operating mode, thereby neutralizing coupling to the unwanted mode. A second set of interspersed ports may be disposed to load degenerate, orthogonal modes.

Abstract: A cyclotron autoresonance maser includes an evacuated drift tube with a first end, a second end and an axis. An electron gun introduces a beam of relativistic electrons to the drift tube first end and, for example, a wiggler magnet causes the electrons to gyrate with the gyrations having relatively small radii. A magnetic field generator is provided which forces the beam of relativistic, gyrating electrons to spiral about the axis of the drift tube. The radii of the spirals is large relative to the radii of the gyrations so that the effective interaction length of the electron beam and a maser beam, having an axis substantially coincidental with the axis of the electron beam, is substantially greater than that of a relativistic electron beam and a maser beam which simply cross. A method of generating coherent radiation is also disclosed.

Abstract: This invention relates to a high-performance gyrotron for the production of electromagnetic millimeter or submillimeter waves with a quasi-optical resonator. The latter is formed by two concave mirrors (1, 2) placed mutually opposite one another on an optical axis. For increasing the decoupling efficiency as well as for reducing the radiation into the environment the quasi-optical resonator is placed in a housing (4), which at least in sections is electrically conductive.

Abstract: A gyrotron device according to the present invention, having an electron gun for emitting an electron beam having an annular cross seciton, coils for applying a magnetic field to the electron beam emitted from the electron gun, a resonator for resonating the electron beam with microwaves and converting energy of the electron beam into microwaves, a collector for collecting the electron beam, a directional coupler for causing microwaves of a predetermined mode to pass, and a waveguide unit for guiding the microwaves from the directional coupler to an external portion.

Abstract: The structures for confining or guiding high frequency electromagnetic radiation have surfaces facing the radiation constructed of high temperature superconducting materials, that is, materials having critical temperatures greater than approximately 35.degree.K. The use of high temperature superconductors removes the constraint of the relatively low energy gaps of conventional, low temperature superconductors which precluded their use at high frequencies. The high temperature superconductors also provide larger thermal margins and more effective cooling. Devices which will benefit from the structures of the invention include microwave cavities, millimeter-wave/far infrared cavities, gyrotron cavities, mode converters, accelerators and free electron lasers, and waveguides.

Abstract: A tilt-angle gun provides a conically-shaped electron beam formed in a magnetically-shielded region which is injected into a coaxial waveguide of the amplifier embodiment of the invention and into a coaxial cavity of the oscillator embodiment immersed in the main magnetic focussing system to form a hollow gyro beam of large radius. RF power input and the amplified rf power output are simply and easily provided through circular input and output waveguides coupled respectively to each end of the coaxial waveguide by slotted sections. The electron beam and the output rf energy are naturally physically separated so that extraction of the rf output is facilitated and occurs with little rf power loss.

Abstract: A free-electron laser has a wiggler for a linear electron beam comprising two sets of magnetic polepieces 26, 28 periodically spaced along opposite sides of the beam. The polepieces of one set 28 are displaced along the beam from the other set 26 by one-half period. A uniform longitudinal magnetomotive force generates fields between polepieces having transverse components 22 alternating between the sets 26, 28, providing a very short periodicity and hence, high frequency wave radiation.

Abstract: A helix slow-wave circuit for use in a linear-beam microwave tube device, comprises a first helix formed by a first wire-like member wound in a first sense at a plurality of turns, and a second helix formed by a second wire-like member wound at a plurality of turns in a second sense opposite to the first sense so as to coaxially surround and superpose on the first helix so that the first and second helixes intersect each other at suitable intervals along an axial direction of the helixes. The first helix is fixed to the second helix in at least some of intersecting points between the first and second helixes.

Abstract: A gyrotron device including an electron gun for emitting a hollow electron beam, solenoid coils for generating magnetic fields so as to produce a cyclotron movement to the electron beam emitted from the electron gun, a plurality of ring mirrors arranged in the direction of the beam axis of the electron beam, and an optical resonator for resonating the electromagnetic waves produced when the electron beam is injected along the magnetic field lines. The optical resonator includes a slotted reflecting mirror so that a portion of the electromagnetic waves propagating within the resonator is reflected upstream to intersect and interact with the electron beam plural times. In order to maximize energy absorption by the electromagnetic waves, the solenoid coils are separately excited so as to shift the radius of the electron beam .lambda./4 within the resonator, .lambda. being the wavelength of electromagnetic waves.

Abstract: An orotron for generating near millimeter wavelength radiation at a selectable output frequency within a wide frequency range, in which the orotron output power is automatically tuned electronically at the selected output frequency. A piezoelectric electromechanical positioning device is connected between the two mirrors forming the open resonator of the orotron to determine the mirror separation in accordance with a position control signal. The electron beam acceleration voltage, which determines the orotron output frequency, and the position control signal are adjusted simultaneously so as to tune the output power at a single oscillation mode of the orotron resonator over a wide frequency range. In the preferred embodiment, the actual output frequency is detected and compared with the selected output frequency, and the beam acceleration voltage and mirror separation simultaneously adjusted to continuously tune and maintain the orotron output at the selected frequency.