Abstract: The average power capacity of a rotating-anode X-ray generator tube is limited by the slow radiation cooling of the anode. The invention removes this limitation by rotating the entire vacuum envelope so the heat can be conducted directly to the air or to a circulating liquid. The cathode and anode are made as figures of revolution about the axis. A stationary source of X-rays is produced by focusing a stationary spot of the light onto a rotating photocathode. The photoelectrons are drawn off and focused onto a stationary spot on the rotating anode, to produce a stationary source of X-rays.

Abstract: In an electron beam tube such as a gyrotron, electron dissipation on the collector wall is often quite non-uniform due to radial concentrations of the electrons. The dissipation is made more uniform by pseudo-random scrambling of trajectories by transverse magnetic fields which are non-uniform in transverse and axial dimensions.

Abstract: A tube for amplifying high-frequency multi-kilowatt, amplitude-modulated signals utilizes a linear beam of electrons which is density-modulated by a permeable control grid spaced close to a thermionic cathode. The beam is focused through a drift tube having two axially spaced gaps, each coupled to a resonant circuit such as a hollow cavity. The first circuit is tuned to a resonant frequency higher than the signal frequency to produce velocity-modulation bunching of the beam electrons in phase with the density-modulation from the grid. The second circuit is tuned to the signal frequency and its energy is coupled out to an external load. The grid modulation is Class B or Class C so there is no current between the electron bunches. The floating bunching circuit can thus, by velocity modulation, produce very dense bunches to excite the output circuit, providing very high conversion efficiency.

Abstract: In a crossed-field amplifier tube, an input section of slow-wave circuit is part of the cathode electrode. An output section of slow-wave circuit is part of the anode electrode. The anode circuit is axially displaced from the cathode circuit in the direction of drift of the electron stream so that a non-propagating section of the anode faces at least a part of the propagating cathode circuit.

Abstract: A calorimetric load for very high microwave power at very high frequencies is formed by a metallic, cylindrical chamber into which the wave-guide carrying the power opens. Inside the metallic cylinder is a coaxial dielectric cylinder, with a space between full of circulating wave-absorbing fluid such as water. The incoming wave may be in a higher-order mode. To make it disperse rapidly into the absorbing fluid, a conical reflector is located inside the dielectric cylinder to reflect the wave outward.

Abstract: A coaxial magnetron has a high-Q resonant cavity surrounding a multiple-resonator anode circuit and coupled by slots to alternate anode resonators. The cavity is resonant in the TE.sub.111 mode, having two zero points of electric field on its periphery. The anode circuit is correspondingly resonant in its N/2-1 mode.Mode suppression means damp out the degenerate TE.sub.111 mode which is not coupled to the output iris.The size and weight of the magnetron are much less than conventional tubes using a cavity resonant in the TE.sub.011 mode with circular electric field.

Abstract: A double-coupled ladder circuit for a traveling-wave tube has been a slow-wave circuit formed of a pair of combs, each cut from a single piece of metal. Transverse grooves are cut in each piece to form teeth and axial grooves are cut in the ends of the teeth. The two combs are joined at teeth ends to form a ladder with the transverse grooves aligned to form cavities and the axial grooves aligned to form a beam passageway. Coupling apertures are cut in both sides of a first set of alternating ladder rungs and a second set of apertures cut in the comb backing members over the second, interleaved, set of rungs. Thus, each cavity is coupled on two opposite sides to its preceding cavity and on the two remaining sides to its following cavity. The double coupling provides increased bandwidth and efficiency. Finally, side plates are affixed to cover the apertures, complete the cavity walls and form the vacuum envelope.

Abstract: A coupled-cavity slow-wave circuit for a millimeter-wave TWT is formed by forming cavities through a metallic bar or half-cavities in a pair of comb-shaped bars. The ends of the cavities are covered by cover members, one of which has a longitudinal groove to form "in line" coupling apertures between cavities.

Abstract: The "comb-quad" slow-wave interaction circuit for a traveling-wave tube consists of a pair of metallic ladders whose rungs cross, the rungs of one ladder passing through the spaces between the rung of the other ladder.The phase velocity of the circuit wave is tapered to a lower value at the output end by gradually enlarging the axial open spaces between the longitudinal bases of the ladders and the surrounding envelope. The periodic elements of the ladders are all exactly alike, simplifying the construction.The slowing of the wave velocity is greater at the lower-frequency end of the passband, providing improved efficiency over the operating band.

Abstract: In a gyro-monotron oscillator a single, "monotron" cavity is used to interact with the electron beam. To handle very high powers without excessive cavity loss, the cavity is excited in a higher order mode such as TE.sub.0m1. Other modes can be resonant in the cavity, interfering with the operation when their frequency is near the operating frequency.To increase the mode separation, an upstream section of the cavity is made smaller, to support only a lower-order mode such as TE.sub.011. Also, the beam is pre-bunched by this lower order, interference-free mode so has less tendency to interact with spurious modes in the higher order cavity.

Abstract: An electron beam tube is described, having a flat cathode and a flat, close-spaced grid to density modulate the beam. The beam passes through an apertured anode and then through a hollow drift tube which is the central conductor of a coaxial resonator. A gap in the drift tube extracts wave energy from the density modulated beam.The cathode-grid region is electrically isolated from the output resonator by the length of the drift tube which is cut off as a waveguide. The circuit is thus completely grounded-grid. The input resonator, a coaxial line connected across the cathode-grid space, is loaded by the input conductance, so as to reduce the gain. The invention increases the gain by introducing regeneration between the grid-anode space and the cathode-grid space. This is done by a coupled coaxial resonator system.

Abstract: An electron-beam tube for generating high microwave power at high frequencies comprises a fast-wave circuit such as a hollow waveguide. The circuit wave has a component of electric field perpendicular to its propagation axis. This field interacts with motions of the electrons transverse to the axis, in particular cyclotron rotation in an axial magnetic field. The above features are common to the well-known "gyrotrons".In the inventive tube the fast-wave circuit has means for locking a linearly polarized transverse-electric mode to the orientation of a circuit member such as the ridge in a ridged waveguide. The member (ridge) rotates spirally with distance along the guide. The added periodicity permits interaction with a space harmonic of the circuit wave. The -1 harmonic has a dispersion characteristic which provides beam-wave interaction over a wider frequency range than is possible in prior-art tubes of the gyrotron type.

Abstract: Photovoltaic solar cells have improved efficiency when constructed in monolithic form with two different band gap energy junctions. Solar light goes first through an upper layer containing a high band gap energy junction which absorbs the short-wavelength components of light. Then the remaining long-wavelength components are absorbed in a second active layer containing a low band gap energy junction. The cell may comprise p-n-n-p type layers.According to the invention, each low band-gap, low-voltage junction is made to have 1/2 the voltage of the high band-gap high-voltage junctions. The junctions are then connected such that the high-voltage junctions are in parallel and the series connection of low-voltage junctions is also in parallel with them. The junction voltages are invariant so the parallel connection works for any light spectrum.

Abstract: Some electrons reflected from the collector of a klystron form a beam current flowing back toward the input end of the tube. This beam is modulated and can carry a regenerate signal which distorts the tube's performance when amplifying a television signal. The reflected electrons are removed by a spiralling transverse magnetic field having a pitch equal to the cyclotron wavelength in the axial magnetic field used to focus the beam. The rotative sense of the spiral is such that forward-going beam electrons are not affected but returning electrons are accelerated in their cyclotron orbits until they are driven outside the beam and are collected.

Abstract: In a microwave electron tube such as a gyrotron, a hollow beam of electrons passes thru the interaction cavity into an output waveguide carrying the generated energy in a mode with circular electric fields. According to the invention, the beam is caused to expand, passing thru a gap in the waveguide to be collected on a larger, surrounding collector. The collector energy is thus reduced. The wave energy jumps the gap and continues down the waveguide. Wave energy leaking into the collector may be absorbed by lossy material therein or be carried off by waveguides to external loads.

Abstract: A solenoidal magnet coil is used to generate an axial field for focusing a beam of electrons through a linear-beam electron tube. In high-power tubes, the coil typically cannot extend over the entire length of the focused electron beam because it would interfere with the waveguide used to carry out the generated wave power. Thus the axial magnetic field strength falls off near the output end, a region in which it would be desirable to have it uniform or even slightly increasing. Very often the coil is foil-wound and its output end has a notch to allow passage of the waveguide. A similar notch 180 degrees away compensates the sideways distortion of field caused by displacement of coil current away from the notch impediment. In the non-notched regions the current spreads throughout the coil cross-section, but there is still a fall-off of field strength on the axis due to current displacement away from the output end.

Abstract: A slow-wave circuit suitable for a high-frequency traveling-wave tube has an array of metallic ladder rungs extending transversely across an elongated envelope and not in contact with the envelope except at the ends of the rungs. The envelope has a cross-shaped section to provide a fundamental backward wave. The rungs preferably have aligned apertures to pass a beam of electrons in traveling-wave interaction with the circuit.By making the rungs transversely broader than a critical value, the lowest passband of the circuit has poles of impedance at both its ends, whereby more efficient interaction is obtained, along with greater stability.

Abstract: This invention concerns a slow-wave circuit which is electrically equivalent to the well-known folded-waveguide or coupled-cavity circuit with staggered coupling slots. The central portion of the circuit is a metallic ladder. The ladder rungs are wide and flat to form the equivalent of flat cavities. The rungs have axially aligned holes thru their centers for beam passage. A pair of coupling ladders are joined to opposite sides of the central ladder. They have apertures or recesses spaced at twice the pitch of the central ladder; the recesses are aligned to provide a coupling duct between each pair of adjacent cavities, and cavity-closing walls at the ends of the pair. The coupling recesses in the two coupling ladders are staggered by the cavity pitch so that the coupling ducts are on alternating sides of the cavities.

Abstract: In a standing-wave coupled-cavity linear particle accelerator the energy of the emergent particles can be adjusted by making the accelerating fields in one section of the accelerator different from those in another section into which the rf drive power is introduced. To do this the adjoining end cavities of the two sections are coupled through a "side" cavity which is not traversed by the particle beam. The coupling coefficients of the side cavity to the two accelerating cavities are made unequal to create the difference in accelerating cavity fields. Asymmetrical coupling is realized by varying the extension of center conductor posts into the side cavity by means of a vacuum sealed mechanism for moving the center posts while maintaining microwave current connection between the center posts and the side cavity.

Abstract: In a gyrotron electron tube of the gyro-klystron or gyro-monotron type, having a cavity supporting an electromagnetic mode with circular electric field, spurious resonances can occur in modes having noncircular electric field. These spurious resonances are damped and their frequencies shifted by a circular groove in the cavity parallel to the electric field.