Abstract: A lamp (10) includes an optics module (12) and an electronics module (14, 60, 70). The optics module (10) includes a plurality of LEDs (76) arranged on a printed circuit board (18) and having a plurality of input leads, and a heat sink (22) having a conduit (40) for the input leads. The plurality of LEDs (16) thermally communicate with the heat sink (22). The electronics module (14, 60, 70) is adapted to power the plurality of LEDs (16) through the input leads. The electronics module (14, 60, 70) has a first end (52) adapted to rigidly connect with the heat sink (22), and a selected electrical connector (50, 62, 72) arranged on a second end for receiving electrical power. The electronics module (14, 60, 70) further houses circuitry (80) arranged therewithin for adapting the received electrical power (82) to drive the LEDs (16).

Abstract: A bulb-shaped fluorescent lamp adopting an inexpensive and highly reliable electronic ballast is provided. A fluorescent arc tube, an electronic ballast, and a base are provided. The electronic ballast lights and drives the fluorescent arc tube, and the base provides a power to the electronic ballast. The electronic ballast has an inductor connected in series to the fluorescent arc tube, and at least two capacitors constituting a resonant circuit with the inductor and connected in parallel to the fluorescent arc tube. At least two capacitors are disposed on the surface of a printed board on the base side. At least two capacitors are disposed stepwise in such a manner that bodies thereof are not opposed to each other and the body with a larger capacitance is spaced further from the fluorescent arc tube.

Abstract: A fluorescent lamp lighting apparatus includes a fluorescent light emitting tube; and an electronic lighting circuit for applying an electric current to the fluorescent light emitting tube. The electronic lighting circuit includes a pair of electrode filaments provided in the fluorescent light emitting tube, a pair of capacitors each connected in series to a respective one of the pair of electrode filaments and connected parallel to the fluorescent light emitting tube, and an inductor connected in series to one of the pair of electrode filaments.

Abstract: A single triac on a heat sink is replaced by a plurality of lower rated current, parallel connected triacs for carrying the same total current as the single triac. The plural devices are spaced apart as far as possible, within the confines of an insulation back cover, to reduce the thermal gradient across the heat sink and to reduce the input thermal power to the heat sink. Thermally conductive compressive sheets thermally couple the flat heat sink to a face plate on the side of the heat sink opposite to the side receiving the triacs.

Abstract: A planar fluorescent lamp having a resistive trace and optically transmissive cover electrodes is described. In one embodiment, the lamp includes an insulative lamp body with the transparent cover electrodes supported by the lamp cover. The resistive trace is supported by the base, either as an exterior resistive trace or within the lamp. The resistive trace acts as a heating element by producing heat in response to an electric current passed through the resistive trace. Because the resistive trace is in thermal contact with the lamp body, heat produced by the resistive trace heats the lamp, improving cold starting. The cover electrodes and, in some embodiments, the resistive trace, are used to control electric fields within the lamp body by applying voltage potentials between discrete cover electrodes or between the cover electrodes and the resistive trace. The controllable electric fields improve cold starting and uniformity of light during low light operation.

Abstract: An insulating enclosure for an electronic ballast has at least one major surface and a thermally conductive heat spreader at the major surface. The heat spreader is thermally coupled to at least one of the electronic components within the ballast and has an area greater than the area of the component as measured parallel with the major surface. The electronic components are thermally coupled to the heat spreader by a thermally conductive, deformable means such as caulk or by domes or dimples in the heat spreader that accommodate the variations in height among the electronic components. An electrically insulating layer can be located between the heat spreader and some of the components to prevent the heat spreader from electrically shorting the components.

Abstract: An illumination device includes a cold cathode fluorescent tube having a heat capacity of 0.035 Wsec/.degree. C. or less per unit length (1 cm) of a glass tube of a fluorescent section of the cold cathode fluorescent tube. The illumination device has a superior operation characteristic at a low temperature. The device is driven by a method and is implemented in a display device.

Abstract: A metal halide lamp of the present invention has a ceramic discharge tube and a proximity conductor disposed adjacent to the ceramic discharge tube.

Abstract: A liquid-crystal display arrangement consisting of a liquid-crystal display, a light source constructed as a fluorescent lamp and a heat source which is thermally coupled to the fluorescent lamp. The heat source is formed as an essentially flat sheet on the side of the lamp opposite the display, with the heat source connected is series with a PTC type temperature sensor. In order to achieve a uniform and rapid establishment of the optimum operating temperature of the fluorescent lamp, the heat source is formed by a temperature-controlled foil-type heating element.

Abstract: Fluorescent type lamps are arranged to have high frequency power derived from standard, commercial A.C. sources either directly or from power levels distributed from a master ballast. When the master ballast is employed, it functions as an interface between the primary power source and a distribution network to one or more modules so as to relieve the modules of operations such as initial power form conversions, filtering and power factor correcting which require large components. The module or modules driven by the master ballast output are contained within the lamp envelope or attached as an extension of the lamp envelope. The module is formed of elements mounted as a miniaturized unit configured to fit within the lamp envelope or to attach to the end of the envelope. The module includes oscillator components mounted on an elongated board so as to form an assembly with a cross-section compatible with the perimeter of the envelope itself.

Abstract: A drive circuit for a solar lamp includes a thermistor TH1 that reduces a power supply to a lamp if a Mosfet Q1 to which it is physically mounted becomes too hot. Also, a resistor R37 sets at low voltage level below which the battery will be isolated. This serves to set a lower but safe level than the voltage at which the circuit in block A isolates the battery during optimum operating conditions of the lamp. Such components prevent or at least inhibit the possibility of the battery being discharged beyond a level from which it cannot recover.

Abstract: A fluorescent light source includes a fluorescent lamp, lamp bases attached to opposite ends of the fluorescent lamp, and an electrically insulating substrate connected to the fluorescent lamp. A heating element is positioned on the fluorescent lamp, and a first and second pair of power traces are formed on the electrically insulating substrate. The first pair of power traces are connected to the heating element to provide power thereto. The second pair of power traces are connected to a pair of electrical conductors that provide power to the fluorescent lamp. This fluorescent lamp can be used in a replaceable fluorescent light source unit for a document scanner. The replaceable fluorescent light source unit includes a housing, lamp base receiving members attached to the housing, and registration notches to properly align the fluorescent lamp.

Abstract: A metal halide lamp includes a luminous tube which is sealed and filled with predetermined rare gases and metal halide, a pair of electrodes provided in the inner portion near both ends of the luminous tube, an outer tube which encloses the luminous tube, and a pair of socket connectors electrically connected with the electrodes, wherein the luminous tube cross-section forms an uneven pattern and is pleated along outer and inner surfaces of the luminous tube. The atmospheric pressure in the luminous tube is stabilized to prevent the bending of the arc. Accordingly, the lifetime of the luminous tube is prolonged and high vapor density is obtained, thereby improving luminous efficiency and color rendering by far.

Abstract: The method of conducting a lighting operation of a metallic vapour discharge lamp, to maintain a suitable arc tube temperature, even if the lamp is operated at an input power higher than 160 W/cm of lighting length. A metallic vapour discharge lamp, in which mercury, rare gas, iron and halogen are encapsulated wherein an arc tube is used and which is operated with an internal pressure of 0.5 to 10 psi, an input power of higher than 160 W/cm of lighting length and within a heater having an air injection cooling system. The lamp characteristics are D.ltoreq.28 and simultaneously P/D.ltoreq.14, where the arc tube external diameter is designated D (mm) and the input power/cm of lighting length is designated P (W/m).

Abstract: Fluorescent type lamps are arranged to have high frequency power derived from standard, commercial A.C. sources either directly or from power levels distributed from a master ballast. When the master ballast is employed, it functions as an interface between the primary power source and a distribution network to one or more modules so as to relieve the modules of operations such as initial power form conversions, filtering and power factors correcting which require large components. The module or modules driven by the master ballast output are contained within the lamp envelope or attached as an extension of the lamp envelope. The module is formed of elements mounted as a miniaturized unit configured to fit within the lamp envelope or to attach to the end of the envelope. The module includes oscillator components mounted on an envelope board so as to form an assembly with a cross-section compatible with the perimeter of the envelope itself.

Abstract: A light source device having a controlled current source that maintains a constant intensity of light from the source during changes in light source temperature, particularly at warm-up. The light source is heated to speed up warm-up and to maintain constant temperature of the source during operation under varying ambient temperatures. Control of the current to the light source is determined by the temperature profile circuit with signals via a temperature signal conditioner from a temperature sensor proximate to the light source. Control of the heater is ultimately dictated by temperature sensor signals.

Abstract: A high pressure discharge lamp having a thick film resistor comprising a plurality of resistive elements. A first resistive element is included in a starting circuit for the lamp and a second resistive element is in series with the arc tube during lamp operation for flicker elimination. The integral thick film resistor facilitates mounting and connection of the resistor elements within the lamp envelope. Favorably, the resistor substrate has a surface emissivity of greater than about 0.5, and preferably greater than about 0.9, to provide sufficient radiation cooling within an evacuated outer lamp envelope to prevent resistor failure while keeping the size of the resistor small enough for use as a component in an HID lamp. Additionally, a suitable coating of low vapor pressure thickness covers the solder connecting the metallic resistor terminals to the substrate to prevent evaporation of the solder and its deposition on the inner surface of the outer lamp envelope.

Abstract: An insulator is applied to the ends of a fluorescent lamp which operates in a cold environment. The insulator retains the heat generated by the fluorescent lamp in order to reduce the energy which must be applied to cause the lamp to fire.

Abstract: A lamp assembly includes a tubular incandescent lamp located between the four tube sections of a double twin tube compact fluorescent lamp such that heat is transferred from the incandescent lamp to the fluorescent lamp when the incandescent lamp is energized. A power source provides power to the incandescent lamp and to the fluorescent lamp through a thermal switch. The thermal switch is in thermal contact with the incandescent lamp and the fluorescent lamp. When the lamp assembly is turned on, the switch applies power to the incandescent lamp initially. When the switch is heated by the incandescent lamp to a predetermined temperature, the switch deenergizes the incandescent lamp and applies power to the fluorescent lamp.

Abstract: A plasma source for generating a plasma in a chamber in conjunction with a radio frequency generator is described. The plasma source comprises a coil spiral, at least one insulator and at least one capacitor. The coil spiral conducts the radio frequency wave from the radio frequency generator and induces a plasma in the chamber. It comprises at least two segments. Each insulator and capacitor couple two adjacent segments of the coil spiral together.

Abstract: A gas discharge tube comprises an indirectly heated cathode structure including a hot cathode into which a heater is incorporated. During discharging, the heater is supplied with a discharge current so as to generate Joule heat which is used as a heat source for the hot cathode. To this end, in a drive circuit in which the heater is preheated with a heater power source to initiate the discharging and to light up the discharge tube, followed by supply of discharging power from a discharging maintaining power source, a preheating switch is inserted between the heater and heater power source, and is opened at a start of the discharging and kept opened thereafter.

Abstract: A coupled-cavity delay line for a traveling-wave tube which includes a device for focusing an electron beam along the axis of the delay line for interaction between the electron beam and an electromagnetic wave propagating along the delay line. The focusing device includes an alternate series of permanent magnets and pole pieces which confine resonant cavities on each side. Each of the pole pieces is common to a pair of adjacent cavities and is provided with a drift tube which is positioned at a center thereof and which has a central aperture for passage of the electron beam. Each of the pole pieces is also pierced by at least one intercavity coupling aperture. The delay line also comprises a heat transfer member provided in at least one of the pole pieces to extend from the drift tube to the outside of the pole piece. This heat transfer member is made of a material such as copper having a heat conductivity higher than that of a pole piece.

Abstract: A fluorescent lamp having a multi-U-bent tubular envelope of convoluted configuration is combined with circuit means, a translucent protective cover and a base module to provide an efficient lamp unit of high brightness and long life that is compact enough to be used as a replacement for incandescent lamps in fixtures designed for residential and commerical lighting installations. Various spatial arrangements for including the ballast and starter components of the energizing circuit as integral parts of the compact lamp unit, despite the stringent space limitations, and also venting the cover and base module to provide convection cooling of the convoluted fluorescent lamp and the other electrical components are also disclosed. Tubulations provided on U-bent portions of the lamp envelope serve as phosphor-drainage means during lamp manufacture and are subsequently tipped off to form mercury-condensation chambers within the finished lamp that regulate the mercury-vapor pressure during lamp operation.

Abstract: A fitting for the electrical connection and support of compact electric-discharge lamps of different powers and construction. An electrical series impedance device for the normal operation of the lamps is accommodated in the fitting. These devices also include a resistor (47, 48) which is responsive to the glow current of the lamps and which is arranged to maintain the glow current in the various lamps to which it may be fitted at substantially one and the same level. This is achieved by the fact that the resistor is temperature-responsive and is placed in good thermal contact with a distinct heat source, for example, the series choke (38).

Abstract: A fluorescent lamp assembly having an electronic ballast circuit. A ballast circuit transformer is mounted on a metallic plate having a recess complementary to the transformer, and the metallic plate suppresses conducted RFI. A lamp cover is attached to the metallic plate and heat from the ballast circuit transformer is dissipated by the metallic plate and lamp cover.

Abstract: A coupled cavity travelling wave tube has a coupling wall/ferro-magnetic pole piece formed as an iron-copper-iron sandwich with a coolant channel therein defined at least in part by the inner copper member of the sandwich. Where the coolant channel is defined also in part by a surface of an outer ferromagnetic member, at least that surface is electroplated.

Abstract: A compact fluorescent lamp with a screw base having a lamp with an inner tube, an outer case which is provided at one end of the lamp and includes an operating circuit section therein and has a screw base at one end of the outer case, and a molding compound having excellent insulation and good conduction of heat which is pressed and interposed into the gap between the operating circuit section and the outer case in order to transfer the heat generated in the operating circuit section to the outer case.

Abstract: The dimensions of the resonant cavities of the multiple-beam klystron are determined in such a way as to enable functioning in the TM.sub.0n mode (n=a whole number greater than 1) and drift tubes relative to the beams go through the klystron cavities at places where the electrical field, in the cavities, is at its maximum value. This embodiment results in high-powered klystrons capable at working at high frequencies.

Abstract: A fluorescent lamp electrode heat cutout switch is provided for placement within a fluorescent lamp stem and outside the discharge envelope and is configured such that a resistive heater wire is connected to one electrode lead-in and a bimetallic switch element is connected to the other electrode lead-in and configured upon an insulating support in such fashion that the heat cutout switch receives heat from the resistive heater to activate the switch so that the electrode heat is cut off when the lamp starts and is kept off during normal lamp operation.

Abstract: A high-pressure metal vapor discharge lamp comprising an outer tube, a light emitting tube located within the outer tube and made of a light-transmissive ceramics material, and a fuse electrically connected in series with the light emitting tube, in which said fuse has such a blowing characteristic as given by the following equation and at a rated output during the lighting of the lamp the density of a current through the fuse is not more than 23.9 A/mm.sup.2 :log T.sub.1 <AlogI+BA=-1.02.times.10.sup.-2 (D.sup.2 t)-0.885B=2.64.times.10.sup.-2 (D.sup.2 t)+1.01T: required blowing time (seconds) of the fuseI: blowing current (A) of the fuseD: inner diameter (mm) of the light emitting tubet: wall thickness (mm) of the light emitting tube.

Abstract: A high vacuum sodium vapor lamp whose discharge tube is surrounded by a heating coil connected in series with a switch opening to interrupt the heating after the lapse of a heating period sufficient to allow breakdown of the tube, is also provided with overvoltage protection and especially an element located in the lamp base, for limiting the autoinductive voltage poles to a level sufficient for breakdown of the tube but insufficient to allow breakdown between the terminals of the lamp.

Abstract: In a discharge tube lighting system for use in a vehicle, a heat generating element, which is made of metal material, is formed on an outer surface of a tube element of the discharge tube along the longitudinal direction of the tube element, and a temperature detecting element is provided on a surface of the heat generating element. The heat generating element is electrically driven to heat the discharge tube at a starting period of lighting the discharge tube when a temperature of the heat generating element detected by the temperature detecting element is lower than a predetermined temperature. The heat generating element is formed in a rectangular shape and conformally disposed on a portion of the tube. The heater element has first and second ends which are disposed with respect to the electrodes of the tube to cause an electric field to be provided between each electrode and the corresponding end of the heater element.

Abstract: A high-pressure discharge lamp comprising a discharge vessel (3) enclosed by an outer envelope (1) provided with a neck (10) which is adjoined by a sleeve (20) of a lamp cap (2). The lamp cap (2) accommodates an electrical circuit provided with a semiconductor switching element (26) which controls the discharge current in the operating condition of the lamp. The semiconductor switching element (26) is provided with a cooling member (24) which is preferably secured to the sleeve (20). This lamp may be used without further expedients in combination with a stabilization ballast not adapted to the lamp.

Abstract: A switch circuit is disclosed which warms-up a load prior to complete turn on. The circuit includes a single pole double throw switch and an amplifier. The input to the amplifier connects to the off throw of the switch and the amplifier is rendered nonconducting when the switch is off. However, when the switch is between its off and on position, as it is being thrown on, the amplifier conducts a half wave rectified warm-up current to the load. Then, when the switch is on, the amplifier is bypassed by a short circuit connecting between the on throw terminal of the switch and the load, and the load is driven to 100% capacity via this short circuit.

Abstract: A compact screw-base discharge lamp having an electrical stabilization ballast which occupies a central position in the lamp. The discharge vessel surrounds the ballast. To dissipate the heat generated by the ballast during operation to the environment of the lamp, a thin-walled heat sink of a heat-conductive material is provided between the ballast and the discharge vessel, and bears on the ballast. This body has a collar which extends to the exterior of the lamp.

Abstract: A lamp having a ceramic molding between a cap and a lamp envelope, the current supply conductors passing through the molding between the cap and the envelope. The conductors pass through separate ducts in the molding, one of the conductors includes a fuse accommodated entirely within the duct, and that duct is sealed at an end adjacent the lamp cap by a coherent mass of material such as a base cement. Flashover from a fuse arc to either the other conductor or the lamp cap is prevented.

Abstract: There is disclosed a high pressure metal vapor discharge lamp which contains in an outer bulb a starting circuit connected in parallel with a light emitting tube having at least one pair of main electrodes. The starting circuit includes a ceramic capacitor surrounded by glass material and exhibiting a non-linear voltage-charge characteristic.

Abstract: Convection air-cooling of a compact electric discharge lamp unit that is adapted for use as a screw-in energy-conserving substitute for an incandescent-type lamp bulb is enhanced by partitioning the lamp housing into two separate compartments and providing vents and connecting air passageways that direct ambient air through the respective housing compartments along two different paths--thereby cooling the compartments independently of one another. A light source (such as a convoluted low-pressure discharge lamp) is located within one of the compartments and an electrical circuit for energizing the lamp is located in the other compartment. The "segregated air-flow" mode of cooling prevents heat that is generated by the lamp from being introduced into the compartment that contains the electrical circuit and thus prevents the circuit components from becoming overheated and possibly damaged.

Abstract: In the present apparatus and method, there is first selected a compact fluorescent lamp having a small fluorescent tube and also having a base, there being two contact pins on the base, there also being on such base a starter housing which projects from the base on the side thereof remote from the tube. There is also selected a screw plug having a metal screw portion adapted to screw into a socket for an incandescent lamp bulb, and also having a contact button, the screw portion and contact button being mounted on a hollow insulating body which has a flange at its end remote from the contact button, the flange being recessed and having diametrally opposed boss portions on opposite sides of the body. There is then mounted, on the flange portion, a thin, insulating socket having conductive pin sockets therein adapted to receive the contact pins of the fluorescent lamp. The insulating socket also has an opening adapted to receive the starter housing.

Abstract: The ballast temperature in the base up position of a miniature arc discharge lamp is reduced, increasing its lifetime, by placing a thin transparent thermal convection/radiation baffle between the arc tube and lamp filament, which are the heat source, and the interface of the envelope with the ballast housing. Greater temperature reduction is realized by putting insulation inside the housing cover and reducing the diameter of wires supporting the arc tube and filament, the latter a ballast resistor.

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: In an incandescent lamp having a glass envelope joined to a base member and a filament mounted within the envelope, an improved fuse wire comprises a portion of one or both of the lead-in wires connecting the filament to the base member. The fuse wire is made of an Aluchrom alloy containing Chromium, Nickel and Iron, or is made of a Cronifer alloy containing Chromium, Iron and Aluminum. The Aluchrom or Cronifer fuse wire, upon lamp failure and fuse burnout, exhibits reduced arcing melt-through of the lamp base compared with lamps having prior art fuse wires, for improved safety thereof.Further the Aluchrom or Chronifer fuse wires have an I.sup.2 t energy rating which permits the use of larger diameter fuse wires which can more readily be processed by lamp production machinery than the smaller diameter lamp fuse wires of prior art materials.

Abstract: An envelope comprises a bowl-shaped component with a screw base and a bulb of a translucent material. A fluorescent tube bent a plurality of times and a reactance ballast are encased in the envelope. This fluorescent tube and the reactance ballast are fixed to a supporting plate. The bend part of the fluorescent tube protrudes through the supporting plate toward the side of the bowl-shaped component. A plurality of openings are formed in the bowl-shaped component at parts corresponding to the bend part of the fluorescent tube. A plurality of openings are formed in the supporting plate at parts near the reactance ballast fixed to the supporting plate.

Abstract: Low-pressure mercury vapor discharge lamp comprising a, preferably folded, discharge tube located within a lamp envelope and having electrodes and an electric stabilization ballast, which is partly surrounded by a thin-walled lamp base, which is connected to the envelope.In the region of the connection between the lamp base and the lamp envelope there is a metal plate for cooling the ballast, this heat sink being at the same time a mounting plate for further components in the lamp such as a starter switch.

Abstract: A high efficiency controlled direct current source for operating high pressure mercury or metal halide lamps for use as substitutes for ordinary incandescent lamps. The circuit includes a voltage sensitive circuit for pulsed starting of the arc discharge lamp as well as for the activation of an auxiliary incandescent filament during the warm-up or hot restart of the arc.

Abstract: A fluorescent lamp having a triple-U-bent tubular envelope is combined with circuit means, a translucent protective cover and a threaded base member to provide an efficient screw-in type lamp unit of high brightness and long life that is compact enough to be used as a direct replacement for incandescent type lamps in fixtures designed for residential and commercial lighting. Various structural arrangements for including the ballast and starter components of the energizing circuit as integral parts of the compact lamp unit, despite the stringent space limitations, and also venting the cover and base structures to provide convection cooling of the compacted electrical components are also disclosed.

Abstract: The present invention relates to a lighting unit utilizing an energy efficient arc lamp as the main source of light supplemented by a standby filamentary lamp, the filament serving as a resistive ballast for the arc lamp during normal operation. The lighting unit is designed for functional similarity to an incandescent lamp, the filament providing immediate illumination when the lighting unit is first energized and continuing illumination until the arc lamp itself produces light. In accordance with the invention, if the arc lamp does not start within a predetermined period, the application of starting potentials produced through operation of a solid state switch and a high frequency step-up transformer is discontinued and the lighting unit rendered inactive. Exemplary means includes a positive temperature coefficient thermistor responsive to the temperature rise of the solid state switch.

Abstract: A flashing and sound generating lamp that repeats on-off operation and generates a characteristic audible sound when an electric current is supplied to the lamp. The lamp comprises a thermally bendable member connected in series or in parallel with the lamp filament to effect on-off energization of the filament as a result of the bending of the member due to the presence and absence of radiant heat from the filament, and a concavity is prefabricated into the thermally bendable member to cause the member to bend with a snap action thereby to generate a characteristic sound each time the lamp is turned on and off.

Abstract: A discharge lamp for connection to an associated alternating current power supply. The lamp is provided with two main electrodes and a starting electrode. Two diodes are connected in series, in cathode to anode relationship, between one associated AC power conductor and the starting electrode. In parallel with the diodes is a first capacitor. Connected to the junction between the diodes is a second capacitor which is connected on the other side thereof to a conductor from the other AC power conductor to the main lamp electrode remote from the starting electrode. In operation the second capacitor substantially changes its capacitance responsive to the temperature present with the lamp to effectively make the voltage doubler inoperative.

Abstract: The present invention comprises a device for generating a modulated intense relativistic electron beam (IREB) with an electronically tunable frequency, comprising: a longitudinally running drift tube; a plurality of gaps in the drift tube including a first gap and a second gap, disposed with a predetermined distance 1 therebetween; and a plurality of cavities, with a first cavity disposed around the drift tube at the location of the first gap, and a second cavity disposed around the drift tube at the location of the second gap. These first and second cavities are provided with volumes and a geometry such as to excite a predetermined frequency band below the plasma frequency for the device. A circuit is provided for generating an IREB and injecting this IREB to propagate within the drift tube with a predetermined plasma frequency. Additionally, a main magnetic field generating means is provided for generating a magnetic field for confining the IREB to a desired beam diameter.