Abstract: The present invention relates to methods and systems for fast ferroelectric tuning of RF power used in a particle accelerating system. By adjusting the voltages fed to the ferroelectric phase shift controller, the amplitude and phase of the RF power wave are altered, thus changing the coupling of the power generating circuit and the superconducting cavity. By altering this coupling rapidly, maximum power transfer efficiency can be achieved, which is important given the large amounts of power shunted through the particle accelerating system. In one embodiment, the ferroelectric tuner is optimally made of a magic-T waveguide circuit element and two phase shifters, although other implementations of the system may be utilized. Alternative phase shifters are shown.

Abstract: An RF accelerating cavity includes an accelerating cavity unit and an inductance varying device having a magnetic member connected parallel to an acceleration electrode gap. The RF accelerating cavity is tuned in such a fashion that a charged particle beam acceleration frequency matches a resonant frequency of the RF accelerating cavity by regulating inductance of the inductance varying device in accordance with a changing pattern of the charged particle beam acceleration frequency. Alternatively, impedance of the RF accelerating cavity is increased with the provision of a fixed inductance connected parallel to the acceleration electrode gap when the RF accelerating cavity has a narrow acceleration frequency range.

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: An output power adjusting mechanisms for adjusting output power is provided on a wave guide of a high frequency output section coupled to an output cavity. The output power adjusting mechanisms is located at a position apart away from the output cavity by a distance of ? wavelength or [(? wavelength)×odd number]. The output power adjusting mechanism includes a reflection adjusting part which is provided in the tube wall of the wave guide so as to be displaceable in the inward and outward directions of the output tube. The output power is adjusted by displacing the reflection adjusting part.

Abstract: A petawatt pulsed-power accelerator can be driven by various types of electrical-pulse generators, including conventional Marx generators and linear-transformer drivers. The pulsed-power accelerator can be configured to drive an electrical load from one- or two-sides. Various types of loads can be driven; for example, the accelerator can be used to drive a high-current z-pinch load. When driven by slow-pulse generators (e.g., conventional Marx generators), the accelerator comprises an oil section comprising at least one pulse-generator level having a plurality of pulse generators; a water section comprising a pulse-forming circuit for each pulse generator and a level of monolithic triplate radial-transmission-line impedance transformers, that have variable impedance profiles, for each pulse-generator level; and a vacuum section comprising triplate magnetically insulated transmission lines that feed an electrical load.

Abstract: An energy switch for use in a radiation system includes an element located within a structure having a cavity, the element capable of being biased by a magnetic field, and a device for generating the magnetic field to thereby bias the element. An energy switch for use in a radiation system includes a structure forming at least a part of a cavity, an element coupled to the structure and located outside the cavity, the element capable of being biased by a magnetic field, and a device for generating the magnetic field to bias the element. A method for use in a radiation procedure includes providing a first magnetic field, and using the first magnetic field to create a first bias for an element that is located outside a cavity of an accelerator, thereby changing en electric field associated with the accelerator.

Abstract: The electrode lengths of a plurality of electrodes linearly arranged in an acceleration cavity are proportional to the velocity of a traveling ion beam. Further, the electrode length is so designated that, in each half of a predetermined cycle in the ion beam direction of travel, the absolute value of a difference, relative to a length that is proportional to the beam traveling velocity is equal to or greater than a value corresponding to the phase width of the traveling ion beam, is provided for electrodes that do not exceed three units and that are fewer than electrodes allotted to half the predetermined cycle.

Abstract: An ion implantation apparatus includes an ion beam source for generating an ion beam; an implantation energy controller disposed on a path of the ion beam for controlling the ion implantation energy of the ion beam so that an ion beam having a first implantation energy is created for a first period of time and an ion beam having a second implantation energy is created for a second period of time; a beam line for accelerating the ion beam; and an end station for mounting a substrate, into which the ion beam accelerated by the beam line is implanted onto the substrate.

Abstract: An ion implantation apparatus comprises an ion beam source for generating an initial ion beam, a bundled ion beam generator adapted to change the initial ion beam into a bundled ion beam based on a predetermined frequency to pass the bundled ion beam for a first time while passing the initial ion beam for a second time, a beam line for accelerating the ion beam having passed through the ion beam generator, and an end station for arranging a wafer therein to allow the ion beam accelerated by the beam line to be implanted in the wafer, the end station operating to move the wafer in a direction perpendicular to an ion beam implantation direction, so as to implant the bundled ion beam in a first region of the wafer and the initial ion beam in a second region of the wafer.

Abstract: Many applications in scientific experimentation or industrial production require the generation and shaping of charged particle bunches. A particle bunch shaper can use less expensive and smaller electrical waveform generators when the particle bunch shaper uses a nanocrystalline magnetic material. High voltage switches are examples of electrical waveform generators. A pipe with two conductive sections separated by a ceramic gap can be run through the center of cores made with the nanocrystalline magnetic material to produce the particle bunch shaper. A voltage waveform transmitted from an electrical waveform generator, through a damping circuit, and through a coupling wire running adjacent to the pipe sections can shape charged particle bunches.

Abstract: A particle accelerator device structured and arranged for use in a subterranean environment. The particle accelerator device comprising: one or more resonant Photonic Band Gap (PBG) cavity, the one or more resonant PBG cavity is capable of providing localized, resonant electro-magnetic (EM) fields so as to one of accelerate, focus or steer particle beams of one of a plurality of electrons or a plurality of ions. Further, the particle accelerator device may provide for the one or more resonant PBG cavity to include a geometry and one or more material that is optimized in terms of RF power losses, wherein the optimization provides for a PBG cavity quality factor significantly higher than that of an equivalent normally conducting pill-box cavity.

Abstract: Standing-wave linear accelerators (linac) having a plurality of accelerating cavities and which do not have any auxiliary cavities are provided. Such linacs are useful for industrial applications such as radiography, cargo inspection and food sterilization, and also medical applications such as radiation therapy and imaging. In one embodiment, the linac includes an electron gun for generating an electron beam, and a plurality of accelerating cavities which accelerates the electron beam by applying electromagnetic fields generated by a microwave source. At least two adjacent accelerating cavities of the plurality of accelerating cavities are coupled together by at least one resonant iris. The electromagnetic fields resonate through the plurality of accelerating cavities and the at least one resonant iris.

Abstract: A system for treating target cells with both positive and negative ions comprises a bi-polar beam delivery system configured to create and deliver both positive ion beams and negative ion beams. The bi-polar beam delivery system comprises a bi-polar accelerator configured to accelerate positive and negative ions in the same direction making such a bi-polar beam delivery system practical.

Abstract: A klystron has a plurality of electron beam paths and plural damped disc-shaped cavities. The plurality of electron beam paths cut the cavities and the Klystron amplifier further comprises an annular input cavity and an annular output cavity disposed around the substantially circular external periphery of respective disc-shaped cavities, and in communication with it. The output cavity is arranged to receive RF power from the electron beams, wherein the cavities are arranged to support one of a single resonant rotating wave in a whispering-gallery mode, and a single resonant standing wave in a whispering-gallery mode.

Abstract: Standing-wave linear accelerators (linac) having a plurality of accelerating cavities and which do not have any auxiliary cavities are provided. Such linacs are useful for industrial applications such as radiography, cargo inspection and food sterilization, and also medical applications such as radiation therapy and imaging. In one embodiment, the linac includes an electron gun for generating an electron beam, and a plurality of accelerating cavities which accelerates the electron beam by applying electromagnetic fields generated by a microwave source. At least two adjacent accelerating cavities of the plurality of accelerating cavities are coupled together by at least one resonant iris. The electromagnetic fields resonate through the plurality of accelerating cavities and the at least one resonant iris.

Abstract: A charged particle apparatus, with multiple electrically conducting semispheric grid electrodes, the grid electrodes mounted in a dielectric mounting ring, with hidden areas or regions to maintain electrical isolation between the grid electrodes as sputter deposits form on the grid electrodes and mounting ring. The grid electrodes are mounted to the mounting ring with slots and fastening pins that allow sliding thermal expansion and contraction between the grid electrodes and mounting ring while substantially maintaining alignment of grid openings and spacing between the grid electrodes. Asymmetric fastening pins facilitate the sliding thermal expansion while restraining the grid electrodes. Electrical contactors supply and maintain electrical potentials of the grid electrodes with spring loaded sliding contacts, without substantially affecting the thermal characteristics of the grid electrodes.

Abstract: A device for generating a particle beam includes a particle source, and a structure having a first section and a second section, the first section coupled to the particle source, the first section having a first power input, and the second section having a second power input, wherein the first section is configured to produce a particle beam having a first energy E1, and the second section is configured to increase or decrease the first energy E1 by an amount E2, the absolute value of E2 being less than E1.

Abstract: A method for generating an electron beam includes prescribing a location, and generating an envelope of electrons, the envelope having a waist, wherein the generating is performed such that the waist of the envelope is at or adjacent to the prescribed location. A device for generating an electron beam includes a gun source for generating electrons, and a plurality of electromagnetic cavities coupled in series to form a body, the electromagnetic cavities configured to accelerate at least some of the electrons to create a beam of electrons at an energy level having a value between 5 MeV and 20 MeV, the beam of electrons having a cross sectional dimension that is 0.02 ? (or 2 mm) or less.

Abstract: A novel method of gating electron emission from field-emitter cathodes for radio frequency (RF) electrode guns and a novel cathode that provides a focused electron beam without the need for magnetic fields or a curved cathode surface are provided. The phase and strength of a predefined harmonic field, such as the 3rd harmonic field, are adjusted relative to a fundamental field to cause a field emission cathode to emit electrons at predefined times for the generation of high-brightness electron beams. The emission time is gated responsive to the combined harmonic and fundamental fields and the response of the FE cathode to the combined fields. A planar focusing cathode includes a selected dielectric material, such as a ceramic material, to provide an electron beam emission surface. Metal surfaces are provided both radially around and behind the dielectric material to shape the electric fields that accelerate and guide the beam from the cathode surface.

Abstract: A particle accelerator system, including apparatuses and methods, that is configurable through repositioning of shorting devices therein to operate at different charged particle beam currents while maintaining optimum transfer of electromagnetic power from electromagnetic waves to one or more accelerating sections thereof, and reducing or eliminating reflections of electromagnetic waves. The particle accelerator system includes at least two accelerating sections and an electromagnetic drive subsystem with portions of the electromagnetic drive subsystem being interposed physically between the accelerating sections, thereby making the particle accelerator system compact. The electromagnetic drive subsystem includes, among other components, a 3 dB waveguide hybrid junction having a coupling window in a narrow wall thereof which is shared by the junction's rectangular-shaped waveguides.

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: An accelerator for accelerating a particle beam includes a main body having a plurality of electromagnetic cavities coupled in series, and a first coupling body having a first side cavity coupled to one of the electromagnetic cavities through a first opening, and to another of the electromagnetic cavities through a second opening, wherein the first opening and the second opening have different configurations. The accelerator further includes a pair of conductive capacitively coupled noses secured to side walls of the first coupling body, wherein the pair of noses have equal lengths.

Abstract: A laparoscopic tumor therapy method and an articulated electron beam transport system are provided for use with a high power, long focus electron source for tumor therapy. The high power, long focus electron source generates an e-beam. The e-beam is transported through a laparoscopic tube proximate a target tumor for electron irradiation therapy.

Abstract: Disclosed is a diagnostic resonant cavity for determining characteristics of a charged particle beam, such as an electron beam, produced in a charged particle accelerator. The cavity is based on resonant quadrupole-mode and higher order cavities. Enhanced shunt impedance in such cavities is obtained by the incorporation of a set of four or more electrically conductive rods extending inwardly from either one or both of the end walls of the cavity, so as to form capacitive gaps near the outer radius of the beam tube. For typical diagnostic cavity applications, a five-fold increase in shunt impedance can be obtained. In alternative embodiments the cavity may include either four or more opposing pairs of rods which extend coaxially toward one another from the opposite end walls of the cavity and are spaced from one another to form capacitative gaps; or the cavity may include a single set of individual rods that extend from one end wall to a point adjacent the opposing end wall.

Abstract: According to the present invention, a non-isochronous magnetic field distribution in which the magnetic field increases as the radius increases is formed and a distribution of fixed-frequency accelerating RF voltage is formed, said non-isochronous magnetic field distribution and said distribution of fixed-frequency accelerating RF voltage being formed so that a harmonic number defined as a ratio of the particle revolution period to the period of the accelerating RF voltage decreases in integer for every particle revolution.

Abstract: A dual-plunger energy switch assembly for standing wave linear particle beam accelerators capable of operating in a higher energy mode and a lower energy mode employs two mechanical plungers that can be extended different distances inside two side cavities of the linear accelerator. When the linear accelerator is operated in the higher energy mode, both plungers are retracted out of the side cavities. To achieve high output while the linear accelerator is operated in the lower energy mode, the two plungers are radially inserted into the two side cavities to adjust the electromagnetic accelerating field along the length of the accelerator, e.g., one plunger is inserted into a side cavity so that the plunger touches the smile surface of the side cavity, while the second plunger is inserted into a second side cavity so that the plunger is adjacent to, but not touching, the smile surface of the side cavity.

Abstract: A particle accelerator system, including apparatuses and methods, that is configurable through repositioning of shorting devices therein to operate at different charged particle beam currents while maintaining optimum transfer of electromagnetic power from electromagnetic waves to one or more accelerating sections thereof, and reducing or eliminating reflections of electromagnetic waves. The particle accelerator system includes at least two accelerating sections and an electromagnetic drive subsystem with portions of the electromagnetic drive subsystem being interposed physically between the accelerating sections, thereby making the particle accelerator system compact. The electromagnetic drive subsystem includes, among other components, a 3 dB waveguide hybrid junction having a coupling window in a narrow wall thereof which is shared by the junction's rectangular-shaped waveguides.

Abstract: The invention relates to a device and a method for producing, from any previously configured ion beams, precisely localized small packages of ions which all fly at the same velocity. The invention consists of damping the ions in a damping-gas filled series of apertured diaphragms (which are firstly subjected alternately to the two phases of an RF voltage and secondly to a multiphase low-frequency travelling field voltage) into the axis of the apertured diaphragm arrangement and packaging the ions in bundles which are propelled axially at the same velocity for ions of different specific masses. These ion packages, which are restricted both in an axial and a radial direction, can be used to advantage for injection into different types of mass spectrometer, both storage ion-trap mass spectrometers, such as cyclotron resonance mass spectrometers or quadrupole ion traps and, especially, for time-of-flight mass spectrometers with orthogonal injection.

Abstract: A niobium cavity exhibiting high quality factors at high gradients is provided by treating a niobium cavity through a process comprising: 1) removing surface oxides by plasma etching or a similar process; 2) removing hydrogen or other gases absorbed in the bulk niobium by high temperature treatment of the cavity under ultra high vacuum to achieve hydrogen outgassing; and 3) assuring the long term chemical stability of the niobium cavity by applying a passivating layer of a superconducting material having a superconducting transition temperature higher than niobium thereby reducing losses from electron (cooper pair) scattering in the near surface region of the interior of the niobium cavity. According to a preferred embodiment, the passivating layer comprises niobium nitride (NbN) applied by reactive sputtering.

Abstract: The present invention relates to an apparatus for pre-acceleration of ions and optimized matching of beam parameters used in a heavy ion application comprising a radio frequency quadruple accelerator (RFQ) having two mini-vane pairs supported by a plurality of alternating stems accelerating the ions from about 8 keV/u to about 400 keV/u and an intertank matching section for matching the parameters of the ion beam coming from the radio frequency quadruple accelerator (RFQ) to the parameters required by a subsequent drift tube linear accelerator (DTL).

Abstract: Some embodiments include an accelerator waveguide to receive RF power, the accelerator waveguide comprising a side cavity, an element fixedly disposed within the side cavity, and a device coupled to the element, wherein the device and the element are operable to control a resonant frequency of the side cavity.

Abstract: An axial extractor to efficiently extract microwave power from any magnetron. The axial extractor is both more compact and offers improved overall performance compared to the prior art. The axial extractor allows for suppression of the parasitic magnetron 0 mode, lowers field stress inside the device, and lowers the frequency of operation. These improvements also make it possible for the magnetron itself to be made smaller without a loss of power output.

Abstract: An RF window and a method of manufacture of the RF window are provided. The RF window of the invention has very low reflected RF power. The RF window includes a center sleeve assembly including a ceramic disc mounted within a copper sleeve. The ceramic disc has opposed surfaces, a ceramic surface coating is applied to each of the opposed surfaces. The ceramic surface coatings are selected for a particular application of the RF window. A pair of end assemblies is removably assembled with the center sleeve assembly. An end assembly mating face is arranged for adjustable slip fit engagement within the copper sleeve of the center sleeve assembly to define a respective cavity on opposed sides of the ceramic disc with the mating face positioned at an adjusted position. An intermediary ring is fixedly secured to the end assembly with the mating face at the adjusted position.

Abstract: A novel method of gating electron emission from field-emitter cathodes for radio frequency (RF) electrode guns and a novel cathode that provides a focused electron beam without the need for magnetic fields or a curved cathode surface are provided. The phase and strength of a predefined harmonic field, such as the 3rd harmonic field, are adjusted relative to a fundamental field to cause a field emission cathode to emit electrons at predefined times for the generation of high-brightness electron beams. The emission time is gated responsive to the combined harmonic and fundamental fields and the response of the FE cathode to the combined fields. A planar focusing cathode includes a selected dielectric material, such as a ceramic material, to provide an electron beam emission surface. Metal surfaces are provided both radially around and behind the dielectric material to shape the electric fields that accelerate and guide the beam from the cathode surface.

Abstract: A method of producing synchrotron radiation comprising the steps of accelerating and compressing an electron beam generated from an electron source by means of a pre-accelerator, further accelerating the electron beam in a main accelerator to produce synchrotron radiation on a recirculation orbit, decelerating the electron beam in the main accelerator to recover its energy and discarding it into a beam dump, said pre-accelerator being an energy-recovery pre-accelerator and posited before the main accelerator on said recirculation orbit so that it also performs energy recovery through beam deceleration, thereby reducing the rf power it is supplied with externally for beam acceleration.

Abstract: A standing wave electron beam accelerator and x-ray source is described. The accelerator has a plurality of on-axis resonant cells having axial apertures electrically coupled to one another by on-axis coupling cells having axial apertures. The accelerator includes a buncher cavity defined in part by an apertured anode and a half cell. The buncher cavity is configured to receive electrons injected through said anode aperture and r.f. focus them into a beam which is projected along the axis through said apertures. An x-ray target is supported in spaced relationship to said accelerator by a support having a smaller diameter than the accelerator.

Abstract: The present invention relates to an apparatus for pre-acceleration of ions and optimized matching of beam parameters used in a heavy ion application comprising a radio frequency quadruple accelerator (RFQ) having two mini-vane pairs supported by a plurality of alternating stems accelerating the ions from about 8 keV/u to about 400 keV/u and an intertank matching section for matching the parameters of the ion beam coming from the radio frequency quadruple accelerator (RFQ) to the parameters required by a subsequent drift tube linear accelerator (DTL).

Abstract: A standing wave electron beam accelerator and x-ray source is described. The accelerator has a plurality of on-axis resonant cells having axial apertures electrically coupled to one another by on-axis coupling cells having axial apertures. The accelerator includes a buncher cavity defined in part by an apertured anode and a half cell. The buncher cavity is configured to receive electrons injected through said anode aperture and r.f. focus them into a beam which is projected along the axis through said apertures. An x-ray target is supported in spaced relationship to said accelerator by a support having a smaller diameter than the accelerator.

Abstract: A cathode ray tube (CRT) has an electron gun including a cathode for emitting electron beams, a control electrode for controlling emission of the electron beams from the cathode, and a screen electrode for accelerating the flow of the electron beams passing the control electrode are arranged in series. In the CRT, during a scanning period, a voltage applied to at least one of the control electrode and the screen electrode changes in response to a voltage of a data signal applied to the cathode. The control electrode and screen electrode each include three mutually electrically insulated sections for independently controlling each of three electron beams passing through the electrodes.

Abstract: Provided is an electron beam apparatus which can limit the influence of aberration of a secondary optical system without the need for providing a diaphragm in the optical system, which comprises a multi-emitter type thermal cathode that reduces shot noise, and which has a multi-emitter and a Wehnelt electrode placed in parallel with each other to permit easy and accurate alignment therebetween. In one embodiment, electron beams emitted from an electron beam source are irradiated to a first aperture plate having a plurality of apertures to generate a plurality of primary electron beams which are directed onto a sample. Secondary electrons emitted from the sample are separated from a primary optical system, directed to a secondary optical system as groups of secondary electrons, and focused on a detector, so that the detector outputs detection signals of the secondary electron beams. A second aperture plate having a plurality of apertures is provided in front of the incident plane of the detector.

Abstract: A cavity for use in an accelerator is formed by an inner wall including at least two different materials. According to embodiments of the present invention, a portion of the structure forming the inner wall of the cavity includes a first material (e.g., copper) while another portion forming the inner wall of the cavity includes a second material (e.g., steel). Using different materials for different portions of the inner walls forming a cavity may cause different Q-factors for the cavity while the shape of the cavity remains constant.

Abstract: A linear induction accelerator, comprised of an injector block, acceleration block, the outlet device, and a drive source. The acceleration block is made from not less than two electrodynamically bound acceleration blocks of the single-channel linear induction accelerators, which are mutually oriented in such way that the direction of the electric field in any of the working channel is opposite to the electric field direction at least in one of the neighboring single-channel blocks of the single-channel linear induction accelerators. The invention allows a decrease of the real dimensions of the accelerator structure, increase of the electromagnetic compatibility level, technology and user safety, and a simplification of structure.

Abstract: An integrated RF amplifier and resonator is provided for use with an ion accelerator. The amplifier includes an output substantially directly coupled with a resonator coil. The amplifier output may be coupled capacitively or inductively. In addition, an apparatus is provided for accelerating ions in an ion implanter. The apparatus comprises an amplifier with an RF output, a tank circuit with a coil substantially directly coupled to the RF output of the amplifier, and an electrode connected to the coil for accelerating ions. Also provided is a method for coupling an RF amplifier with a resonator in an ion accelerator. The method comprises connecting the RF output of the amplifier to a coupler, and locating the coupler proximate the coil, thereby substantially directly coupling the RF output of the amplifier with the resonator coil.

Abstract: Methods and apparatus are provided for efficiently operating an ion implanter which includes a charged particle accelerator in a high energy mode and in a low energy mode. The charged particle accelerator includes a high voltage power supply, an accelerator column coupled to the high voltage power supply and a switching assembly. The accelerator column includes a plurality of accelerator electrodes. The high voltage power supply is disabled from energizing the accelerator column in the low energy mode. The switching assembly includes switching elements for electrically connecting the accelerator electrodes to a reference potential in the low energy mode and for electrically isolating the accelerator electrodes from the reference potential in the high energy mode. The switching assembly prevents positive potentials on the accelerator electrodes and thus minimizes space charge expansion of the beam when transporting positive ion beams in the low energy mode.

Abstract: A device for use in a linear accelerator operable to accelerate charged particles along a beam axis is disclosed. The device includes a plurality of monolithic members connected to form a series of accelerating cavities aligned along the beam axis and coupling cavities. Each of the coupling cavities intersects with adjacent accelerating cavities at first and second coupling apertures. The first and second coupling apertures have different sizes.

Abstract: A cavity for use in an accelerator is formed by an inner wall comprised of at least two different materials. According to embodiments of the present invention, a portion of the structure forming the inner wall of the cavity may be comprised of a first material (e.g., copper) while another portion forming the inner wall of the cavity may be comprised of a second material (e.g., steel). Using different materials for different portions of the inner walls forming a cavity may cause different Q-factors for the cavity while the shape of the cavity remains constant.

Abstract: A method, system, and apparatus for providing reduced dark current in a linear accelerator includes a cavity having an input aperture and an output aperture, and a particle source coupled to the input aperture, the input aperture having a radius greater than a radius of the output aperture.

Abstract: A continuous wave electron-beam accelerator that accelerates a continuous wave electron beam having a large average current includes an electron beam generator, an electron-beam accelerating unit using a radio-frequency electric field having a frequency of approximately 500 MHz to accelerate an continuous wave electron beam, and electron-beam bending units located across the electron-beam accelerating unit and that bend the continuous wave electron beam a number of times. Each electron-beam bending unit includes divided magnets having identical-polarity magnetic fields, and controls the continuous wave electron beam so that the beam passes through the electron-beam acceleration unit a number of times on almost the same path.

Abstract: A method, system, and apparatus for providing reduced dark current in a linear accelerator includes a cavity having an input aperture and an output aperture, and a particle source coupled to the input aperture, the input aperture having a radius greater than a radius of the output aperture.

Abstract: A standing wave linear accelerator with a prebunching section and an accelerating section that are formed into a unitary accelerating structure is described. The prebunching section is configured to group charged particles into bunches by velocity modulation of the charged particle beam. The accelerating section has a plurality of inter-coupled resonant cavities, including an input cavity that is coupled to the prebunching section and an output cavity.