Abstract: A transverse field interaction multi-beam amplifier device comprising a structure having, for example, a plurality of discrete cathodes cylindrically located in succession along a central axis of RF propagation. In registration with the cathodes are a respective number of annular collectors located within an outer cylinder which also acts as the structure housing. Intermediate the cathodes and collectors are two additional coaxial cylinders, one having a relatively smaller diameter than the other, with the smaller diameter cylinder including respective number of discrete grids, while the larger cylinder comprises a structure preferably having a rippled or undulating slow wave wall surface and a respective number of annular slots formed therein.

Abstract: A millimeter coupled cavity travelling wave tube has each of its slow wave structures formed of at least one longitudinally extending member having holes made therethrough by a hobbing process, which holes constitute at least in part the cavities of the slow wave structure. In a preferred embodiment a one and one only such longitudinally extending member is provided, the holes therein each a whole cavity. The hobbing is such that a buttress is left outstanding from each cavity facing surface of a cavity separating wall and the beam hole is bored axially through said member from end to end through said buttresses. After machining of the cavity coupling holes in the cavity separating walls (e.g. by spark erosion) the cavities are closed by plates brazed to opposite faces of the member.

Abstract: A broadband transverse field interaction continuous beam amplifier device mprised of an elongated continuous cathode modulating grid structure, an elongated continuous demodulating grid-collector structure, first or input waveguide transmission line means including the modulating grid for propagating an input RF wave transversely to an electron beam traveling from the cathode-grid structure to the output-collector structure where the electrons are bunched or modulated by the process of transverse wave interaction, and second or output waveguide transmission line means including the demodulating grid for propagating an induced amplified RF output wave resulting from prebunched electrons traversing the demodulator grid. Both input and output transmission line means include slow wave structures which are implemented in the grid structures.

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 generator is provided based on an interaction of the cyclotronic type between an electron beam propagating between an electron gun and a collector and a high frequency electromagnetic field in a resonating structure. It is principally characterized in that the electron beam moves along a cycloidal path in a transverse magnetic field under the effect of a drift velocity created by a continuous electric field.

Abstract: A helix-type delay line borne by a conical surface. The internal surface of a sleeve has grooves into which are inserted dielectric supports of constant height that are affixed to the helix-type delay line, and the depth of the grooves increases with the diameter of the line.

Abstract: A method and apparatus for increasing the power output and efficiency of an orotron generating near millimeter wavelength radiation. In accordance with a theory of orotron operation described herein and confirmed experimentally, the ribbon-like electron beam utilized in the orotron has a very high current density to effect a large increase in orotron output power and efficiency due to space-charge effects in the beam. In the preferred embodiment, the high density electron beam is generated by a closely-packed rectangular array of field-emission cathodes.

Abstract: A wide-band distributed coupler for coupling rf energy from an input waveguide into a tapered interaction waveguide in a traveling-wave amplifier comprising a plurality of channel filters connecting between the input and interaction waveguides, with each filter coupled to the interaction waveguide at the appropriate cross-sectional position along its tapered length where the interaction waveguide cutoff frequency approximately matches the wave frequency propagated by the filter. Each filter comprises, in one embodiment, a main coaxial cavity tuned to a distinct center frequency, a first simple isolation cavity for coupling rf energy between the input waveguide and the main cavity, and at least one second simple isolation cavity for coupling energy between the main cavity and the tapered interaction waveguide. This coupler is compatible both in bandwidth and geometry with the tapered interaction waveguide.

Abstract: The object of the invention is to provide a traveling wave tube with increased linearity to avoid intermodulation of signals being amplified. In a traveling wave tube 10, as shown in FIG. 1, the slow wave structure is a helix (18) including a sever (21). A dynamic velocity taper is provided by gradually reducing the spacing (26) between the repeating elements of the slow wave structure which are the windings of helix (18). The reduction takes place between Zo indicated by line 23 and Z.sub.s which coincides with the output point of helix (18) as indicated by the line (22). The spacing (26) begins to decrease at Z.sub.o and is decreased by up to about 5% at Z.sub.s. The spacing (26) between the repeating elements of the slow wave structure is ideally at an exponential rate because the curve (27), as shown in FIG. 3, increases from Z.sub.o to Zs the point of maximum efficiency and power, at an exponential rate. FIG. 3 shows a coupled cavity traveling wave tube having cavities 32 through 37.

Abstract: A delay line assembly for high-performance traveling-wave tubes having an electron beam generating system and an electron beam collector, includes a copper vacuum enclosure, a delay line in the form of a ring ribbon conductor disposed in the vacuum enclosure between the electron beam generating system and the electron beam collector, and a plurality of dielectric mounting rods extended parallel to the ring ribbon conductor in the vacuum enclosure for supporting the delay line, the ring ribbon conductor being formed of a relatively more highly thermally stressed tungsten part and a relatively less highly thermally stressed molybdenum part.

Abstract: An electron gun of the type comprising two electrodes facing each other and brought to different potentials so as to create therebetween a continuous electric field and a cathode positioned in the extension of the electrode at negative or zero potential and brought to the same potential as this latter, the assembly being subjected to a magnetic field perpendicular to the electric field. In the plane perpendicular to the magnetic field, at least one of said electrodes has a divergent profile so that the distance between electrodes increases from the cathode towards the outside of the gun.

Abstract: This invention refers to a traveling-wave tube with cylindrical evacuated sheath 3, which is surrounded by a permanent-magnet system including pole shoes 1 and magnet rings 2 inserted between the pole shoes, while pole shoes 1 inserted in evacuated sheath 3 and the parts of them that surround beam axis 7 are designed as small tubes 4. Every second pole shoe is coupled as an active pole shoe 1 to magnet ring 2, and pole shoes 5 that are inserted between are connected with evacuated sheath 3. This traveling-wave tube is capable of focusing with greater efficiency and at higher frequencies than existing systems. This invention also provides that active pole shoes 1, which are coupled to magnet rings 2, are made of magnetic metal and that at least front ends 8 of small tubes 4 are made of non-magnetic metal. In addition, pole shoes 5 inserted between are made of non-magnetic and their small tubes 6 of magnetic metal.

Abstract: The invention provides a travelling wave tube comprising means for suppressing parasite oscillations and these means are formed by auxiliary helical delay lines placed inside the sleeve in the gaps between two adjacent dielectric supports, periodically fixed to the sleeve by metal supports and without contact with the main helical delay line.

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: A dual-mode electron gun for a traveling-wave tube is disclosed which selectively generates an electron beam of two different cross-sectional areas. The electron gun includes radially inner and annular control grids as well as a shadow grid disposed between the cathode and the control grids along the electron beam path. The shadow grid is provided with a suppressor ring which precludes electron emission from an annular portion of the cathode immediately radially outwardly of the cathode region over which the inner control grid projects, thereby eliminating generation of a spurious beam portion radially outwardly from the desired smaller cross-section beam.

Abstract: A delay line is provided for a travelling wave tube and comprising two parts:a first part formed from a delay line section comprising a central conductor mounted in a cylindrical sleeve by means of dielectric rods. This first part is situated on the high frequency input side of the tube and is focussed by means of a succession of permanent magnets with alternate orientations;a second part, following the first one which is formed from an entirely metal delay line section and which is focussed by means of a solenoid or a permanent magnet.

Abstract: A surge arrester includes an elongated insulating housing comprising one or more stacks of electrically series-connected metal oxide varistor blocks arranged between a top terminal and a bottom terminal. To achieve a more even voltage distribution in the longitudinal direction of the surge arrester, the surge arrester comprises larger varistor blocks at the top terminal than at the bottom terminal.

Abstract: A traveling-wave tube having a cylindrical vacuum envelope surrounded by a permanent-magnet system of ring-shaped pole washers and magnet rings respectively disposed therebetween and having opposite polarizations alternatingly in axial direction, which includes spacer rings formed of nonmetallic material surrounding the cylindrical vacuum envelope and spacing the magnet rings therefrom, corresponding magnet rings and spacer rings being soldered together into respective strong and stable units.

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 deflection structure (10) of the traveling wave type includes first and second deflection members (52 and 58) positioned on opposite sides of and extending along the path of an electron beam (26) to deflect the beam in response to deflection signals applied to the deflection members. In a preferred embodiment, both deflection members are of a meander line type which include a plurality of deflection plate segments (74, 76) connected in series by a plurality of lead portions (78) to form a pair of transmission lines, each transmission line having a characteristic impedance that tends to vary with distance along the path of the electron beam due to a flared spacing between the output portions of the deflection members. Pitch compensation including different pitches for the first and second deflection members increases and maintains substantially uniform the characteristic impedance of each transmission line to prevent reflection of the deflection signal back toward the input end of the line.

Abstract: A wide band travelling wave amplifier including an input waveguide coaxia disposed about an interaction waveguide. Both waveguides are tapered with the same direction of increasing cross-section. The interaction waveguide is a high-pass filter while the input waveguide is a low pass filter. The input waveguide is positioned relative to the interaction waveguide so that each cutoff plane in the input waveguide corresponding to a given frequency, .omega..sub.c, is displaced in the direction of increasing cross-section from a cutoff plane in the interaction waveguide corresponding to .omega..sub.c where .omega..sub.c is any frequency in the frequency band of the amplifier. A slot, disposed between the cutoff planes corresponding to .omega..sub.c couples the .omega..sub.c frequency component of an input wave from the input waveguide to the interaction waveguide.

Abstract: A lightning arrester of the station class is equipped with a ceramic housing protective heat shield liner formed of an ablative material capable of giving off a gas when subjected to a fault current arc. The evolved gas contributes to a rapid internal pressure buildup calculated to rupture housing end sealing diaphragms and quickly vent the arrester housing interior to prevent housing fracture. The arrester end structures are provided with expansive radial vents to accommodate unimpeded internal pressure relief.

Abstract: There is disclosed a traveling wave tube with a slow wave structure having means for frequency and directionally sensitive wave amplification. The slow wave structure includes a conductive helix coaxially mounted within a conductive tubular housing and a conductive support structure longitudinally disposed within the housing and extending transversely from the helix to the housing. In some embodiments, the support structure is combshaped and in one embodiment is a helical ridge wound in registration with and in the same sense as the helix. The pitch of the housing and a preselected parameter of the support structure are simultaneously varied along the length of the helix such that a wave at a given frequency band traveling along the slow wave structure in a first direction is preferentially amplified with respect to waves traveling in an opposite direction.

Abstract: A surge arrester comprises two or more surge arrester units which are electrically series-connected between a top terminal and a bottom terminal. Each surge arrester unit comprises a stack of metal oxide varistor blocks, the latter being distributed within the surge arrester so that the number of varistor blocks per unit length in the surge arrester unit which is nearest the bottom terminal is less than in the surge arrester unit which is nearest the top terminal. This enables a more even temperature distribution to be achieved throughout the length of the surge arrester especially in the case where the surge arrester is located where it is subjected to long-term external fouling or pollution.

Abstract: A cathode/grid assembly for effecting a dual power mode electron gun for use with a traveling wave tube. The conventional "shadow grid" is both electrically and mechanically isolated from the cathode. A variable voltage source is connected to the shadow grid to bias it slightly above or slightly below the cathode potential, depending on the power mode. The electron emitting surface area of the cathode is the same in both modes. By changing the bias on the shadow grid, the transverse beam temperature may be increased to compensate for the reduced space charge density of the low power mode. Thus, the diameter of the low power beam is substantially the same as the diameter of the high power beam. This ensures good beam transmission and high electron beam rf interaction in the low power mode.

Abstract: A disconnector for a surge arrester explosively separates an electrical lead wire, normally a ground lead wire, from the arrester to prevent a permanent fault and to provide an indication of a failed arrester. The disconnector includes an elongated, frangible insulating housing having an elongated opening disposed along and parallel to the longitudinal axis of the insulating housing; a first electrically conductive terminal disposed at a first end of the opening; a second electrically conductive terminal disposed at a second end of the opening; means for forming an arc gap disposed between the first and second terminals, including an arc gap spacer and an arc electrode being either generally flat or including a raised portion; and an explosive cartridge disposed between the first and second terminals and in contact with the arc electrode.

Abstract: A surge voltage arrester, with a column of arrester elements arranged in a housing and several shielding bodies enclosing the column, includes voltage controlling elements arranged between the shielding bodies. The size and type of fastening of the voltage controlling elements can correspond to that of the support bodies which are likewise arranged between the shielding bodies. Through a distribution of the voltage controlling elements over the length of the surge voltage arrester, a uniform voltage distribution can be achieved if the arrester is installed in a grounded metal housing.

Abstract: A surge arrester including an outer porcelain housing and an ablative heat shield liner is disclosed herein along with a number of techniques for making the surge arrester break resistant. In accordance with one of these techniques, a blow out or relief valve is provided on at least one end of the arrester housing for venting internal pressure due to electrical arcing therein. In this embodiment, an arrangement is provided for preventing the components therein from escaping during the venting procedure. The liner is constructed of a material which is sufficiently ablative to produce its own gas within the housing in response to electrical arcing therein.

Abstract: A ladder circuit especially useful in backward wave oscillators operating in the 500 GHz to 2,000 GHz range comprises a waveguide (10) having disposed therein transversely oriented slabs (16) which contact an upper wall (22) of waveguide (10). The edges of slabs (11) adjacent the physical center of waveguide (10) along which is directed an electron beam (19) have respective curved segments (11) and stubs (12) and (13) of electrically conductive, non-magnetic material supported thereon. The ends of slabs (16) include metal layers (17) and (18) at respective opposite ends to provide a conductive leakage path. A ridge bar (20) is attached to the inside of the bottom wall (21) of the waveguide (10) and includes a concave upper surface which partially straddles electron beam (19). The inside width of the waveguide (10) is approximately one-half wavelength as determined by the frequency of operation of the backward wave oscillator.

Abstract: A termination device for absorbing RF energy waves in the termination chamber of a traveling wave tube. The termination device is formed by modifying two wedge shaped termination devices of the prior art. Specifically, two well known single wedge termination devices are sliced in half to produce two wedges each one half the thickness of the prior art single wedge device. The two halves are positioned with their newly formed surface, formed by the slicing, in opposed facing contact. The new double wedge thus has the same thickness as the prior single wedge and is readily accommodated within the termination chamber. The double wedge termination device greatly reduces small signal gain variations across the operating frequency band of the traveling wave tube.

Abstract: In the last section of a delay line having coupled cavities for a traveling-wave tube, the following parameters are progressively increased in the direction of propagation of the electron beam: the diameter of the opening provided for the passage of the electron beam, thus making it possible to ensure better transmission of the beam and consequently to ensure higher efficiency as well as lower heat build-up; the ratio (D.sub.2 -D.sub.1)/2 of the cavity nozzles; and the thickness of the walls which are common to two adjacent cavities.

Abstract: This surge suppressor comprises a tubular insulating housing having a metal end cap at one end and an integral end wall at its opposite end. A metal terminal extends through the end wall and has a portion within the housing. A stack of metal-oxide varistor blocks has one end bearing against said terminal portion and an external periphery spaced from the surrounding wall of the housing. A metal plate at the other end of the stack is urged against said other end of the stack by a spring between the end cap and the plate. A plurality of ceramic rods fixed to the end wall extend alongside said stack and through holes in the end plate and serve to limit such lateral motion of the stack as produced by vibrations and mechanical shocks.

Abstract: An improved slow wave circuit especially useful in backward wave oscillators includes a slow wave circuit (10) in a waveguide (12) as shown in FIG. 1. The slow wave circuit is comprised of rings 11 disposed between and attached to respective stubs (13,14). The stubs (13,14) are attached to opposing sidewalls of the waveguide (12).To the end that opposed, interacting magnetic fields will be established to provide a very high coupling impedance for the slow wave structure, axially orientated bars (20) are connected between rings in alternate spaces and adjacent to the attachment points of stubs 13. Similarly, axial bars (21) are connected between rings in the spaces which do not include bars (20) and at points adjacent to the attachments of bars (21).FIG. 2 shows the current loops (22,23) available because of the inventive structure.FIG. 3 shows that rings 11 may be half rings of 180.degree. arc.FIG. 4 illustrates that the rings or half rings (11) with stubs (13,14) may be formed of flat metal ribbons.

Abstract: Two coupled cavity type, slow-wave circuits are separated, with a drift space section between them. An electron beam and an electromagnetic wave, which do not interact with each other, over a certain length, are in the drift space. A waveguide type non-reflective termination structure has a waveguide axis directed in the same direction as the electron beam and is coupled to the cavity, slow-wave circuits with respect to a high frequency wave disposed in the drift space section. With such a construction, a traveling wave tube is formed with a PPM focusing and with a non-reflective termination structure includes a waveguide member having a through-hole for passing an electron beam and two waveguides formed on the opposite sides of the through-hole. A lossy ceramic member is disposed within one of the two waveguides for a forwardly traveling wave and another lossy ceramic member is disposed in the other waveguide for a backwardly traveling wave.

Abstract: The invention relates to a high gain crossed field amplifier tube.Such a tube comprises in a vacuum enclosure 1 a cathode 2 and a delay line 3, itself constituted by an input line 31 whose height is less than that of the output line 32.The invention is applied to radio transmission systems.

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: Travelling wave tube, including a cylindrical vacuum shell having an outer diameter, a permanent magnet system surrounding the cylindrical vacuum shell including ring-shaped pole shoes having inner and outer diameters, magnet rings having inner and outer diameters and forming pairs with the pole shoes, each of the magnet rings being alternatingly disposed between two pole shoes in axial direction and being poled in opposite sense with respect to the next magnet ring, the inner diameters of the pole shoes being closely fitted around the vacuum shell and being smaller than the inner diameters of the magnet rings, the outer diameters of the magnet ring being larger than the outer diameters of the pole shoes, and a centering and retaining ring being adjacent to and in contact with each of the pole shoe and magnet ring pairs for centralizing the inner diameters of the pole shoes to the outer diameters of the magnet rings and for centralizing the inner diameters of the pole shoes and the outer diameters of the magn

Abstract: A surge arrester including an outer elongated housing and an inner liner is disclosed herein. The outer housing is constructed of a material which will not break as a result of internal electrical arcing, specifically a relatively resilient, electrically insulating and non-tracking material which in a preferred embodiment is EPDM rubber. In order to add structural integrity to the arrester, its inner liner is constructed of a high strength material, preferably resin impregnated fiberglass.

Abstract: In a travelling wave tube in which the delay line (1) is constituted by a sequence of double resonator cavities (15) alternating with the pole pieces (3) of the focusing system, the invention provides for the purpose of limiting the interception of electrons by the line an increase in the diameter of the magnetic material collars (30, 40) terminating said pieces, as well as the wall (16) of the cavities on the side of the tube axis. This increase takes place in stages, a collar (40) having the same diameter as the collar (30) which follows it in the beam propagation direction.

Abstract: A thermionic fault current limiter utilizes either a vacuum or plasma environment for a plurality of spaced conduction electrodes. The electrode can be supported by insulative spacers with the electrode providing shadow shields for the supporting spacers. Electrode spacing, power density, temperature gradients, and control grids can be utilized for optimum operation and in establishing self-absorption of energy for a desired operating environment. Cesium desorption from the electrode surfaces can be utilized to enhance current termination.

Abstract: A power connector for providing overload protection for an electrical operating station connected to a power mains, composed of at least one overvoltage arrester of a first type which is capable of quenching the power mains surge current and at least one overvoltage arrester of a second type connected in series with said arrester of the first type, with the insulation of one overvoltage arrester, in its unfired state, meeting the requirements of a basic insulation or of the supplementary insulation for a protective insulation, and both arresters being constructed for dissipating the pulses generated by a direct stroke of lightning or nuclear electromagnetic pulses without adversely affecting the protection afforded thereby.

Abstract: The thickness of the fingers of the line is modified, while the pitch of the fingers is kept constant, so that the capacitance between two successive fingers varies substantially proportionally to the product P.sub.HF .times.dI/dx, in which P.sub.HF represents the microwave power at any point x in the line and dI/dx the gradient, as a function of the position x on the line, of the current I delivered by the voltage supply creating a continuous electrical field E.sub.o between the electrodes of the tube. The values of P.sub.HF and of I are measured on the tube having a constant coupling resistance or are calculated by a computer program.

Abstract: A helix-type traveling wave tube delay line extends from an input side to an output side. An electron gun adjacent the input side of the helix means transmits an electronic beam to a collector adjacent the output side. An attenuator divides the helix at a location between the input side and the output side. Between the attenuator and input, the helix has a pitch (P.sub.0). Between the attenuator and the output, the pitch (P.sub.1) of the helix is greater than the pitch (P.sub.0) to form a fast velocity circuit. The pitch (P.sub.2) of a second part of the helix between the attenuator and output is less than the pitch (P.sub.0) to form a slow velocity circuit. A third part of the helix is interposed between the first and second parts to form a velocity taper section having a helical pitch which varies from the larger pitch (P.sub.1) to the smaller pitch (P.sub.2). One fairly central position in the third part of the helix has an average pitch of (P.sub.1 +P.sub.2)/2. A first length (L.sub.

Abstract: A helical microwave delay line for a travelling-wave tube, constituted by a conductor held in the envelope of the tube by insulating bars. The width of the conductor in contact with the supporting bars increases along the tube axis, particularly towards the microwave energy output.

Abstract: A crossed field amplifier including a linear, ladder type slow wave device ncluding an array of closely spaced parallel U-shaped rungs with a pair of oppositely wound helices running side-by-side inside said array, and a pair of trimmers running along each side of said array of rungs, the trimmer height at the input or cathode end of said slow wave structure being increased compared to its height for the remainder of said slow wave device.

Abstract: A filter for suppressing backward wave energy modes propagating along a slow-wave structure. The filter is frequency responsive and comprises a wall having coupling apertures and, in one embodiment, a series of waveguide sections which are joined to the coupling apertures and alternate sections are terminated in matched loads. The apertured wall encloses the slow-wave structure and the apertures are arranged relative to periodic elements of the slow-wave structure such that a forward wave can propagate with substantially no interaction with the filter while the energy in a backward wave is dissipated in the matched loads. The filter is particularly adapted for absorbing backward waves in a travelling wave tube operating at high power and an octave bandwidth.

Abstract: The spark gap device disclosed herein comprises at least two sets of electrodes enclosed within a common chamber. A delay line is connected between successive sets of electrodes. An arc which develops across the first set of electrodes as a result of a voltage transient ionizes the gas in the chamber. The voltage transient is delayed by the time required to travel through the delay line. When the voltage transient arrives at the second set of electrodes, an arc develops in less time than was required at the first set of electrodes due to the fact that the gas in the chamber has been at least partially ionized.

Abstract: A slow-wave, cyclotron-type, travelling-wave-tube amplifier in which the m-wave interaction is the result of a Weibel-type instability. The travelling wave is slowed down in its propagation through the waveguide by a dielectric liner located on the inner wall of the waveguide. The bunching mechanism is the result of the V.sub..perp. .times.B.sub..perp. Lorentz force.

Abstract: In a microwave tube of the type wherein an electron beam emitted by an electron gun is focused and caused to interact with an input high frequency wave at a high frequency circuit unit by magnetic flux generated by a periodic permanent magnet assembly, and the electron beam after the interaction is collected by a collector unit, the portion connected to the output unit of the high frequency circuit unit comprises a column-shaped waveguide member having an end surface comprising a portion of the wall of a cavity at the end of the high frequency circuit unit, the member being bored with a central aperture at the center axis to allow electron beam to pass from the electron gun to the collector unit. A waveguide for guiding the electromagnetic waves from the end surface to the output unit is also provided, and the end surface is shaped like a fan.