Abstract: A method and system for automatically conditioning a linear accelerator is disclosed. The method and system comprise the steps of measuring the global variables of the accelerator and evaluating a plurality of events based upon the measurement of the global variables in which the plurality of events have a hierarchy of importance. Finally, the method and system includes performing an action in response to the hierarchy of importance of the plurality of events. Accordingly, a system and method in accordance with the present invention allows an accelerator to be conditioned unattended. The system and method in accordance with the present invention combines software and hardware to measure global variables and modifies the condition of the accelerator based upon those variables. Through the use of a system and method in accordance with the present invention conditioning can proceed in small systematic steps, thereby resulting in better-conditioned accelerators.

Abstract: A method for driving an electric-field electron emission apparatus without degrading the electron emission characteristics is provided. The method can drive the electric-field electron emission apparatus without degrading the electron emission characteristics by allowing application of the electric field only when the second derivative of the captured electron current density exceeds a certain value.

Abstract: A method and apparatus for generating an accurate, stable phase shift (b) in a sinusoidal signal employs fast analog multiplication to implement the trigonometric relationship sin(&ohgr;t+b)=sin(&ohgr;t)cos(b)+cos(&ohgr;t) sin(b). Cos(&ohgr;t) is generated by accurately shifting a signal sin(&ohgr;t) through 90° C. using a delay line, for example. Sin(b) and cos(b) are dc signals generated by digital to analog conversion, using a demanded phase shift (b) whose sine and cosine are obtained from look-up tables. A controller for controlling a phase shift in an rf cavity is also disclosed and operates on the basis of the same trigonometrical principle. The amplitude of the signals in the rf cavity is also controllable; fast analog multipliers are again employed to scale the signal amplitude to a nominal fixed value such as 1 volt.

Abstract: An charge exchanger for changing the polarity of an ion beam includes an charge exchange member provided in the path of an ion beam, and through which the ion beam can pass, and charge conversion material coating the surface of the charge exchange member. The charge conversion material is, for example, a fine powder of particles of magnesium against which the ion beam collides. The charge exchange rate caused by such collisions is controlled based on the measured dosage of ions injected into a target or on predetermined ion injection conditions. First, a desired ion dosage is determined based on the specifics of the ion implantation to be carried out. Then, an ion beam is injected onto a wafer after having been passed through the charge exchanger. Finally, the charge exchange member is advanced at a speed which establishes an charge exchange rate that gives rise to conditions necessary for the specific ion implantation process to occur.

Abstract: A compact high energy photoelectron injector integrates the photocathode directly into a multicell linear accelerator with no drift space between the injection and the linac. High electron beam brightness is achieved by accelerating a tightly focused electron beam in an integrated, multi-cell, X-band rf linear accelerator (linac). The photoelectron linac employs a Plane-Wave-Transformer (PWT) design which provides strong cell-to-cell coupling, easing manufacturing tolerances and costs.

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 improved device utilizing an inductive undulative EH-accelerator is proposed for acceleration and cooling of plasma fluxes, and beams of charged particles, and separate charged particles; and for forming of neutral molecular beams, and neutron beams (inductive undulative EH-accelerator) is proposed. The device consists of an electromagnetic undulation system, whose driving system for electromagnets, is made in the form of a radio frequency (RF) oscillator operating in the frequency range from about 100 KHz to 10 GHz; which is connected with coils of the undulatve system of electromagnets, and a source of accelerated particles, which is provided in the form of source of plasma or neutral molecular beams, or positive or negative ions, or charged particle beams, or separate charged particles.

Abstract: An electron beam accelerator system includes a high power switching device coupled between the direct current voltage source and the pulse forming network. A pulse control circuit is connected to control the high power switching device to selectively allow a current to flow to the pulse forming network. A voltage difference between a cathode and an anode structure creates an electron beam flowing therebetween. A control grid drive circuit is operatively coupled to the pulse control circuit and the control grid, and is operable to apply a time-varying voltage to the control grid synchronized with the pulse control circuit. The control grid therefore effectively provides a load on the high voltage output of a step-up transformer that prevents overshoot in the transformer output, reducing the risk of dielectric breakdown and failure due to transient high voltages.

Abstract: An ion implanter employs two three gap rf accelerator stages to boost the implant energy after mass selection. The electrodes of the accelerator stages have slit-shaped apertures that accommodate high beam current, when the accelerator is in drift mode. By particular choice of the parameters of the accelerator, each stage of the accelerator produces accelerated ions having a relatively small energy spread, even though the acceptance range of the accelerator stage extends over a substantial phase angle of the applied rf voltage. The resulting accelerator is flexible, permitting a wide variation of output energies with good beam dynamics. Ion bunches from the first three gap stage are caused to have the correct flight time to reach the second stage for acceleration by adjusting the speed of the ions while maintaining the rf phase of the fields in the two stages locked to fixed values.

Abstract: A device for use in a linear accelerator operable to accelerate charged particles along a beam axis. The device includes a first end section, a second end section, and a transition section interposed between the first and second end sections. The sections are coupled together to form a plurality of accelerating cavities aligned along the beam axis. The first and second sections are configured to operate in a fixed collective resonant mode and the transition section is tunable such that resonant modes of the transition section may be tuned to lie at generally the same frequency as the resonant mode of the first and second sections.

Abstract: This device allows the variation of the coupling between two points in an RF circuit in a very simple way while maintaining the RF phase relationship and varying the relative magnitude of the RF fields. The device is characterized by a simple mechanical control of coupling value, that has negligible effect on the phase shift across the device. This is achieved by the simple rotation of the polarisation of a TE111 mode inside a cylindrical cavity. Such a device does not contain resistive elements, and the sliding mechanical surfaces are free from high RF currents. This device finds an application in standing wave linear accelerators, where it is desirable to vary the relative RF field in one set of cavities with respect to another, in order that the accelerator can operate successfully over a wide range of energies.

Abstract: A thin vacuum valve for particle accelerator beam lines comprising of a frame, a slide, a shaft, a first clamp, and preferably a second clamp, which is easily constructed from highly electrically conductive material and presents substantially smooth, flat surfaces towards adjacent particle accelerator component. The frame has first and second surfaces respectively facing toward the two adjacent particle accelerator system components, the first surface including a slide slot. A frame orifice extends through the frame between the first and second surfaces, preferably at the slide slot, and is positioned and sized on the frame to permit passage of a particle beam generated by the particle accelerator system along a beam line The slide is housed substantially within the slide slot and is movable between a first position and a second position along a slide axis. In the first position, the slide permits a particle beam to pass through the slide orifice and through the frame orifice along the beam line.

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

Abstract: Systems and methods for reducing dark current levels in a standing wave linear accelerator without sacrificing operating performance are described. In a radiation mode, the standing wave linear accelerator is operated to produce a pulsed therapeutic photon beam having a characteristic pulse width. In an electron mode, the standing wave linear accelerator is operated to produce a pulsed therapeutic electron beam having a characteristic pulse width that is shorter than the characteristic pulse width of the therapeutic photon beam. In some embodiments, assuming a uniform dark current level, the dark current level may be reduced in proportion with the beam pulse width reduction in the electron mode of operation. A system for implementing this therapeutic beam generation method also is described.

Abstract: The objective of the invention is a process for producing a rigidified structure, comprising at least one element with superconducting properties, and the means for rigidifying, this process comprising a stage of deposit by plasma spraying of a layer of material on a surface of said element.

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

Abstract: A new radio frequency (rf) linear accelerator (linac) is disclosed in this invention. The rf linac includes a plurality of resonators each includes an inductor circuit L(k), k=1,2,3, . . . , n′ where n′ is a second integer, wherein the inductor circuit connected to at least two electrodes E(j′), j′=1,2,3, . . . (n−1), for applying an accelerating rf voltage thereto. The rf linac further includes a plurality sets of transverse focusing lenses, represented by Lenses(j), where j=1,2,3, . . . n, and n is an integer, for guiding and focusing an ion beam. Each of the electrodes E(j′) disposed between and aligned with two sets of the transverse focusing lenses Lenses(J′) and Lenses(J′+1), j′=1,2,3, . . . (n−1), as a linear array. In a preferred embodiment, at least two of the adjacent electrodes E(j′) and E(j′+1) are connected to a same inductor circuit L(k).

Abstract: A method and apparatus for generating an accurate, table phase shift (b) in a sinusoidal signal employs fast analog multiplication to implement the trigonometric relationship sin(&ohgr;t+b)=sin(&ohgr;t)cos(b)+cos(&ohgr;t)sin(b). Cos (&ohgr;t) is generated by accurately shifting a signal sin(&ohgr;t) through 90° using a delay line, for example. Sin(b) and cos(b) are dc signals generated by digital to analogue conversion, using a demanded phase shift (b) whose sine and cosine are obtained from look-up tables. A controller for controlling a phase shift in an rf cavity is also disclosed and operates on the basis of the same trigonometrical principle. The amplitude of the signals in the rf cavity is also controllable; fast analogue multipliers are again employed to scale the signal amplitude to a nominal fixed value such as 1 volt.

Abstract: A standing wave accelerator structure that has both inline coupling cavities and side coupling cavities combined into one structure. Additionally, the invention uses a prebunching (re-entrant) cavity, excited electrically or magnetically, through apertures between a first accelerating cavity and the prebunching cavity.

Abstract: The closed electron drift plasma thruster uses a magnetic circuit to create a magnetic field in a main annular channel for ionization and acceleration, said magnetic circuit comprises: an essentially radial first outer pole piece; a conical second outer pole piece; an essentially radial first inner pole piece; a conical second inner pole piece; a plurality of outer magnetic cores surrounded by outer coils to interconnect the first and second outer pole pieces; an axial magnetic core surrounded by a first inner coil and connected to the first inner pole piece; and a second inner coil placed upstream from the outer coils. The thruster also comprises a plurality of radial arms included in the magnetic circuit, and a structural base which is separate from the magnetic circuit and which serves, amongst other things, to cool the coils.

Abstract: A dielectric-wall linear accelerator is improved by a high-voltage, fast rise-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface.

Abstract: A resonator circuit capable of resonating at a predetermined frequency is provided. The resonator circuit comprises a fixed position coil inductor (62) having a longitudinal axis (92) and a capacitor (88, 82) electrically connected in parallel with each other to form a resonator (60), so that respective first and second ends of the inductor and the capacitor are electrically coupled together at a high-voltage end (64) and a low-voltage end (66) of the resonator (60). A radio frequency (RF) input coupling (70) is coupled directly to the inductor (62) at the low-voltage end (66) of the resonator. A high-voltage electrode (72) is coupled to the high-voltage end (64) of the resonator. A first resonator tuning mechanism is provided for varying the inductance of the inductor, comprising a plunger (90) movable within the coil of the inductor (62) along the longitudinal axis (92). A second resonator tuning mechanism is provided for varying the capacitance of the capacitor (88, 82).

Abstract: RFQ electrodes for use as an acceleration tube of a high energy ion implanter, capable of accelerating an ion beam of large current without divergence are arranged, with respect to a low resonance frequency of substantially 33 MHz suitable for heavy ions such as B, P, and As, such that a radius R1 of a beam passage spacing surrounded by four RFQ electrodes is 5 mm to 9 mm, a curvature R2 in a direction perpendicular to an axis of a crest portion of repetitive crest and trough portions on surfaces of the electrodes in a beam propagation direction is 5 mm to 9 mm, and a height H from a peak of the crest portion to a bottom surface is set so that H/R1 is 4 to 6. When the height H of the electrodes is reduced, while shunt impedance is increased and power efficiency is improved, a cooling ability becomes insufficient due to the fact that a cross section of a coolant channel cannot be increased, and a problem is presented that oscillation of electrodes is likely to occur due to insufficient mechanical strength.

Abstract: A compact coil design is provided for a linear accelerator resonator (70) capable of resonating at a predetermined frequency. The coil (90) comprises a plurality of generally circular coil segments (90a-90n), each of the coil segments having a polygonal cross section wherein flat surfaces (122) of adjacent coil segments face each other. The polygonal cross section may take the form of a rectangle having dimensions of length x and width y, wherein dimension x section defines the flat surfaces (122) of adjacent coil segments (90a-90n). The coil segments (90a-90n) are provided with a dual channel construction for providing the introduction of a cooling medium into the coil. The dual channel construction comprises an inlet passageway (118) and an outlet passageway (120) having separate a separate inlet (100) and outlet (102), respectively, at a first end (94) of the coil, and wherein the inlet and outlet passageways (118, 120) are connected and in communication with each other at a second end (96) of the coil.

Abstract: A drift tube linear accelerator (DTL) incorporating an improved drift tube design, wherein the DTL comprises a resonance chamber maintaining a vacuum and having an inlet port and an exit port, an RF field source producing an oscillating radio frequency field within the chamber, and a plurality of substantially cylindrical drift tubes comprising a hollow body having a low energy end and a high energy end and housing a magnet, a low energy end cap attached to the low energy end of the hollow body and a high energy end cap attached to the high energy end of the hollow body, and a stem extending from said hollow body to an inner surface of the resonance chamber.

Abstract: The disclosure relates to a particle accelerator which comprises two accelerating tubes as well as a charge-exchange channel, whereby the vacuum pump for evacuating from said charge-exchange channel gas particles injected therein is not connected to the high-voltage side but, via a vacuum tube, to the low-voltage side of the particle accelerator. This means a substantial simplification of the maintenance of the vacuum pump. In addition to that a motor and a generator are no longer required. By providing the vacuum pump with equipotential plates, which comprise pump holes arranged eccentrically round the center of the vacuum tube, the gas particles are in this configuration are accelerated while retaining the high breakdown strength.

Abstract: An electron beam accelerator utilizes a single microwave resonator holding a transverse-magnetic circularly polarized electromagnetic mode and a charged-particle beam immersed in an axial focusing magnetic field. The combined effect of the transverse-magnetic microwave fields and the axial magnetic field provide the electron beam with a helical shape and a rotational motion which allows the entire beam to be continually accelerated to high energies in a dc-like fashion. The use of the transverse-magnetic circularly polarized electromagnetic mode allows the resonant frequency to be independent of resonator length--allowing the resonator length to be selected to achieve desired particle acceleration. Using a transverse-magnetic rotating wave mode, TM.sub.110, allows the cavity frequency to be independent of cavity length and eliminates the need for bunched beams and short cavities while allowing the use of a spiraling moving beam.

Abstract: A device which improves the electrical and thermomechanical performance of an RF cavity, for example, in a disk-loaded accelerating structure. A washer made of polycrystalline diamond is brazed in the middle to a copper disk washer and at the outer edge to the plane wave transformer tank wall, thus dissipating heat from the copper disk to the outer tank wall while at the same time providing strong mechanical support to the metal disk. The washer structure eliminates the longitudinal connecting rods and cooling channels used in the currently available cavities, and as a result minimizes problems such as shunt impedance degradation and field distortion in the plane wave transformer, and mechanical deflection and uneven cooling of the disk assembly.

Abstract: In order to obtain a linear electron accelerator having enhanced beam performance, a thermion emitting face 11 of a cathode 10 is enclosed by carbon 17. Consequently, distribution of an electric field 30 for leading out electrons becomes parallel with the thermion emitting face 11. Therefore, electron beams emitted from the thermion emitting face 11 become streamlines parallel with each other. Thus, the beam performance of the linear electron accelerator can be enhanced.

Abstract: In a radio-frequency accelerating system, a loop antenna is coupled with at least one of a plurality of magnetic core groups each including a plurality of magnetic cores or with at least one of the plurality of magnetic cores, and an impedance adjusting means is connected to the loop antenna. A relatively low voltage is applied to the impedance adjusting means. Therefore, the impedance adjusting means may be a circuit element having a low withstand voltage and hence the radio-frequency accelerating system can be formed to have a small construction.

Abstract: A superconducting cyclotron is provided that includes a superconducting magnet. This superconducting magnet is arranged to provide a magnetic field that extends axially through a chamber which includes a radially extending beam space. There is further an interaction within the chamber between the axially extending magnetic field and RF energy that energizes particles that are circulating within the beam space. There is further a linear accelerator that is aligned with and exposed to the axially extending magnetic field of the superconducting cyclotron. The output of this linear accelerator communicates with an input to the beam space so that the particles for acceleration within the beam space are pre-accelerated by the linear accelerator.

Abstract: The invention is related to a plasma technology field, in particular, to plasma accelerators, used in a space technology, in scientific researches and in industry. A technical result is that the accelerator has an increased lifetime which is achieved by reducing in wear of discharge chamber walls. An accelerator with closed electron drift includes a ring anode 1 with an anode cavity 2, a magnetic circuit 3, field coils 4 and pole tips 5 with a ring interpole gap, external 6 and internal 7 ring cathodes, a cathode-compensator 8, a power supply 9, a means forming positive gradient of magnetic field 10 which can be formed by walls of the anode 1 made of ferromagnetic material. Outlet edges of the anode 1 are provided with nozzles 11 made of nonmagnetic material; a nozzle shape coincides with shape of the magnetic field line of force which is tangential to outlet edges of the anode. The anode 1 is connected with a system supplying with gaseous active substance by means of the hole 12.

Abstract: A radio-frequency type charged particle accelerator includes a RFQ accelerator and a rear stage RF accelerator both of which are contained in a single evacuated chamber. The RFQ accelerator has quadrupole electrodes positioned along a traveling path of the charged particle and bunches and accelerates a charged particle beam by receiving a radio-frequency power from a radio-frequency power source and resonating. The rear stage RF accelerator is disposed in a rear stage of the RFQ accelerator and accelerates or decelerates the energy of the charged particle beam accelerated by the RFQ accelerator by receiving the radio-frequency power from the radio-frequency power source and resonating. A separating plate is disposed in the single evacuated chamber to separate the RFQ accelerator from the rear stage RF accelerator so that the RFQ accelerator and the rear stage RF accelerator work independently of each other.

Abstract: A coupled cavity accelerator (CCA) accelerates a charged particle beam with rf energy from a rf source. An input accelerating cavity receives the charged particle beam and an output accelerating cavity outputs the charged particle beam at an increased energy. Intermediate accelerating cavities connect the input and the output accelerating cavities to accelerate the charged particle beam. A plurality of tunable coupling cavities are arranged so that each one of the tunable coupling cavities respectively connect an adjacent pair of the input, output, and intermediate accelerating cavities to transfer the rf energy along the accelerating cavities. An output tunable coupling cavity can be detuned to variably change the phase of the rf energy reflected from the output coupling cavity so that regions of the accelerator can be selectively turned off when one of the intermediate tunable coupling cavities is also detuned.

Abstract: A dielectric-wall linear accelerator is improved by a high-voltage, fast rise-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface.

Abstract: The invention relates to a radio-frequency particle accelerator. First and second cylindrical inner conductors 4 and 5 are disposed on the axis of the particle beams from the particle beam entrance with an accelerating gap interposed between the inner conductors in a TM or TEM mode particle accelerating cavity. An end of the first inner conductor 4 and an end of the second inner conductor 5 are joined to base plates of an outer conductor 3 of the accelerating cavity to form an inductance and together with the capacitance across the gap to form a resonant cavity. In order to synchronize particle beams with the radio-frequency accelerating phases, a bunching gap 11 with an inductance is formed by forming slots 11a on the first inner conductor 4. Thus, a radio-frequency electric power for exciting the accelerating cavity 2 is automatically supplied to the bunching gap 11 through the inductive coupling.

Abstract: A linear accelerator for charged particles includes a plurality of accelerating stages in a linear arrangement along a central axis. Each accelerating stage has at least one passageway radially spaced from the central axis for transmitting a beam of charged particles. Electromagnetic wave energy is coupled to the accelerating stages to produce an accelerating electric field in a region of the passageway of each of the accelerating stages. Coupling circuits couple the electromagnetic wave energy between adjacent accelerating stages. Each accelerating stage may be configured as an annular accelerating cavity or as two or more accelerating cavities disposed around the central axis. The passageway may be configured as two or more discrete apertures or a single annular aperture. Beam bending devices may be used to direct the charged particle beam through the accelerator two or more times. The linear accelerator produces a high current, high energy charged particle beam.

Abstract: A dielectric-wall linear accelerator is enhanced by a high-voltage, fast e-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface.

Abstract: A radio-frequency type charged particle accelerator includes a first Radio Frequency Quadrupole (RFQ) accelerator, a second RFQ accelerator and a rear stage Rf accelerator. The first RFQ accelerator has quadrupole electrodes positioned along a traveling path of a charged particle beam and bunches and accelerates the charged particle beam by receiving a radio-frequency power from a radio-frequency power source and resonating. The rear stage RF accelerator is disposed in a rear stage of the first RFQ accelerator and changes the energy of the charged particle beam by receiving the radio-frequency power from the radio-frequency power source and resonating. The second RFQ accelerator is disposed between the first RFQ accelerator, has quadrupole electrodes positioned along the traveling path of the charged particle beam and normally accelerates the charged particle beam by receiving a radio-frequency power from the radio-frequency power source and resonating.

Abstract: The invention provides a novel laser-plasma-based source of relativistic electrons; and a method to use laser-driven plasma waves as the basis for the source of electrons. The technique involves a combination of laser beams, which are focused in a plasma. One beam creates a wakefield plasma wave. In one embodiment, the one beam creates a wakefield plasma wave and the other beam alters the trajectory of background electrons, such that they become trapped in the plasma wave and are then accelerated to relativistic velocities, preferably in a distance less than a millimeter. In another embodiment, the second beam removes electrons from atomic ions previously generated by the first beam thereby providing electrons which become trapped in the plasma wave and then accelerated to relativistic velocities.

Abstract: A high-gradient linear accelerator comprises a solid-state stack in a vacuum of five sets of disc-shaped Blumlein modules each having a center hole through which particles are sequentially accelerated. Each Blumlein module is a sandwich of two outer conductive plates that bracket an inner conductive plate positioned between two dielectric plates with different thicknesses and dielectric constants. A third dielectric core in the shape of a hollow cylinder forms a casing down the series of center holes, and it has a dielectric constant different that the two dielectric plates that sandwich the inner conductive plate. In operation, all the inner conductive plates are charged to the same DC potential relative to the outer conductive plates. Next, all the inner conductive plates are simultaneously shorted to the outer conductive plates at the outer diameters. The signal short will propagate to the inner diameters at two different rates in each Blumlein module.

Abstract: An RF linear accelerator using CW or low amplitude pulsed RF excitation which can efficiently accelerate charged particles from 0.1 C to relativistic velocities in excess of 0.9 C. A charged particle source feeds charged particles having velocities of about 0.1 C into a first type RF LINAC having a plurality of side coupled resonator cavities each having a drift tube in the middle. The RF length of the cavities is set relative to the velocity of the particles and the RF excitation wavelength such that the particles experience in-phase accelerating E fields in the gaps on either side of the drift tube and are shielded from decelerating E fields while inside the drift tubes. The RF coupling cavities establish sufficient phase change between adjacent resonators such that the particles arrive in the adjacent resonator cavities in synchronization with oscillations in the standing wave therein so as to experience further acceleration. The first RF LINAC accelerates the particles to 0.5 C approximately.

Abstract: In an output resonant cavity used with a linear electron beam tube such as an IOT, magnetic material is mounted on walls of the cavity and defines annular channels within which coils are located to provide focusing of an electron beam travelling along the axis of a tube located in apertures in the cavity walls. An inner rim locates the electron beam tube with respect to the cavity.

Abstract: A method of bunching a charged particle beam including the step of generating an electric field during a certain time duration, the electric field being generally parallel to a travelling direction of the charged particle beam having a kinetic energy of 1 eV to 1 MeV, and an intensity of the electric field changing as a quadratic function of time. In addition to the waveform changing as the quadratic function, a waveform changing linearly may also be used. The linearly changing waveform may be superposed upon a waveform of a half period from phase .pi. to 2.pi. of a sine wave if the linearly changing waveform monotonously increases, or upon a waveform of a half period from phase 0 to .pi. of a sine wave if the linearly changing waveform monotonously decreases. Furthermore, the linearly changing waveform and the sine waveform may be superposed upon a waveform of a half period from phase 0 to .pi.

Abstract: Equipment for achieving uniformalization of energy and pulsing of a particle beam is installed in an accelerated charged particle-beam generator or particle-beam storage ring. For maximum efficiency, a CMC (cyclotron maser cooling) unit for achieving uniformalization of energy and pulsing of the particle beam is introduced to generate a coherent particle beam.

Abstract: A control apparatus for controlling RF power supplied to first and second loads is provided. The control apparatus includes a first symmetric hybrid junction having a first port for receiving input RF power, a second port coupled to the first load and a third port coupled to a dummy load. The control apparatus further includes a second symmetric hybrid junction having a first port coupled to a fourth port of the first symmetric hybrid junction and a third port coupled to the second load. First and second variable shorts are respectively coupled to second and fourth ports of the second symmetric hybrid junction. RF power reflected by the first and second variable shorts is controllably directed through the second symmetric hybrid junction to the second load. The amplitude and phase of the RF power supplied to the second load can be controlled independently.

Abstract: A new charged particle accelerator with radio frequency quadrupole accelerating cavities is presented in this invention. Some focussing coils are mounted outside or inside several cavities of them. The accelerator emits charged particle whose kinetic energy can be varied as occasion demands.

Abstract: The invention provides a method and apparatus for generating large amplitude nonlinear plasma waves, driven by an optimized train of independently adjustable, intense laser pulses. In the method, optimal pulse widths, interpulse spacing, and intensity profiles of each pulse are determined for each pulse in a series of pulses. A resonant region of the plasma wave phase space is found where the plasma wave is driven most efficiently by the laser pulses. The accelerator system of the invention comprises several parts: the laser system, with its pulse-shaping subsystem; the electron gun system, also called beam source, which preferably comprises photo cathode electron source and RF-LINAC accelerator; electron photo-cathode triggering system; the electron diagnostics; and the feedback system between the electron diagnostics and the laser system. The system also includes plasma source including vacuum chamber, magnetic lens, and magnetic field means.

Abstract: A coupled-cavity drift-tube linac (CCDTL) combines features of the Alvarez drift-tube linac (DTL) and the .pi.-mode coupled-cavity linac (CCL). In one embodiment, each accelerating cavity is a two-cell, 0-mode DTL. The center-to-center distance between accelerating gaps is .beta..lambda., where .lambda. is the free-space wavelength of the resonant mode. Adjacent accelerating cavities have oppositely directed electric fields, alternating in phase by 180 degrees. The chain of cavities operates in a .pi./2 structure mode so the coupling cavities are nominally unexcited. The CCDTL configuration provides an rf structure with high shunt impedance for intermediate velocity charged particles, i.e., particles with energies in the 20-200 MeV range.

Abstract: In an apparatus for accelerating electrically charged particles from a pulsed plasma reservoir of high particle density in a dielectric tubular chamber which extends from the reservoir and is surrounded by at least two electrodes of which one is disposed at the wall of the reservoir, the dielectric tubular chamber is partially evacuated to a sufficiently low pressure p such that the product of the gas pressure p and the inner diameter d of the tubular chamber is low enough to avoid parasitic discharges in the residual gas charge, and a voltage is applied to the electrodes such that the particles are drawn into the dielectric tubular chamber with high flow density and are accelerated therein thereby forming a charged particle beam whereby the residual gas charge in the dielectric tubular chamber is ionized along the inside wall of the tubular chamber and polarized such that the wall of the dielectric tubular chamber becomes repulsive for the charged particle beam and its axis becomes attractive whereby the cha