Abstract: A DC conductive, low RF/microwave loss titanium oxide ceramic provides, at room temperature, a bulk DC resistivity of less than 1×1011 ohm-meters and an RF loss tangent of less than 2×10?4 at 7.5 GHz and less than 2×10?5 at 650 MHz. The resistivity is reduced by oxygen vacancies and associated Ti3+ and/or Ti4+ centers created by sintering in an atmosphere containing only between 0.01% and 0.1% oxygen. The reduced resistivity prevents DC charge buildup, while the low loss tangent provides good RF/microwave transparency and low losses. The ceramic is suitable for forming RF windows, electron gun cathode insulators, dielectrics, and other components. An exemplary Mg2TiO4—MgTiO3 embodiment includes mixing, grinding, pre-sintering in air, and pressing 99.95% pure MgO and TiO2 powders, re-sintering in air at 1400° C.-1500° C. to reduce porosity, and sintering at 1350° C.-1450° C. for 4 hours in an 0.05% oxygen and 99.05% nitrogen atmosphere.

Abstract: A DC conductive, low RF/microwave loss titanium oxide ceramic provides, at room temperature, a bulk DC resistivity of less than 1×1011 ohm-meters and an RF loss tangent of less than 2×10?4 at 7.5 GHz and less than 2×10?5 at 650 MHz. The resistivity is reduced by oxygen vacancies and associated Ti3+ and/or Ti4+ centers created by sintering in an atmosphere containing only between 0.01% and 0.1% oxygen. The reduced resistivity prevents DC charge buildup, while the low loss tangent provides good RF/microwave transparency and low losses. The ceramic is suitable for forming RF windows, electron gun cathode insulators, dielectrics, and other components. An exemplary Mg2TiO4—MgTiO3 embodiment includes mixing, grinding, pre-sintering in air, and pressing 99.95% pure MgO and TiO2 powders, re-sintering in air at 1400° C.-1500° C. to reduce porosity, and sintering at 1350° C.-1450° C. for 4 hours in an 0.05% oxygen and 99.05% nitrogen atmosphere.

Abstract: In embodiments, a linac electron beam excited X-ray source weighing less than 50 pounds, and having a volume less than 1 cubic foot, injects electrons from an RF-excited, diamond tip cathode into a dielectric accelerator tube of diameter less than 10 mm, where the electrons are RF-accelerated to 1-4 MeV. A focusing channel having a plurality of annular permanent magnets can surround the dielectric tube, and a vacuum can be maintained in the tube by a getter pump. The accelerating RF can be 10 GHz or higher. The X-ray source can be powered by a rechargeable battery for more than an hour. Embodiments can be transported within a case having a display attached to an interior surface of its lid. An X-ray head can be removed from the case and extended up to 10 feet while remaining interconnected with the case by a flexible conduit.

Abstract: An electromagnetic mechanical pulser implements a transverse wave metallic comb stripline TWMCS kicker having inwardly opposing teeth that retards a phase velocity of an RF traveling wave to match the kinetic velocity of a continuous electron beam, causing the beam to oscillate before being chopped into pulses by an aperture. The RF phase velocity is substantially independent of RF frequency and amplitude, thereby enabling independent tuning of the electron pulse widths and repetition rate. The TWMCS further comprises an electron pulse picker (EPP) that applies a pulsed transverse electric field across the TWMCS to deflect electrons out of the beam, allowing only selected electrons and/or groups of electrons to pass through. The EPP pulses can be synchronized with the RF traveling wave and/or with a pumping trigger of a transverse electron microscope (TEM), for example to obtain dynamic TEM images in real time.

Abstract: An electromagnetic mechanical pulser implements a transverse wave metallic comb stripline TWMCS kicker having inwardly opposing teeth that retards a phase velocity of an RF traveling wave to match the kinetic velocity of a continuous electron beam, causing the beam to oscillate before being chopped into pulses by an aperture. The RF phase velocity is substantially independent of RF frequency and amplitude, thereby enabling independent tuning of the electron pulse widths and repetition rate. The TWMCS further comprises an electron pulse picker (EPP) that applies a pulsed transverse electric field across the TWMCS to deflect electrons out of the beam, allowing only selected electrons and/or groups of electrons to pass through. The EPP pulses can be synchronized with the RF traveling wave and/or with a pumping trigger of a transverse electron microscope (TEM), for example to obtain dynamic TEM images in real time.

Abstract: In embodiments, a linac electron beam excited X-ray source weighing less than 50 pounds, and having a volume less than 1 cubic foot, injects electrons from an RF-excited, diamond tip cathode into a dielectric accelerator tube of diameter less than 10 mm, where the electrons are RF-accelerated to 1-4 MeV. A focusing channel having a plurality of annular permanent magnets can surround the dielectric tube, and a vacuum can be maintained in the tube by a getter pump. The accelerating RF can be 10 GHz or higher. The X-ray source can be powered by a rechargeable battery for more than an hour. Embodiments can be transported within a case having a display attached to an interior surface of its lid. An X-ray head can be removed from the case and extended up to 10 feet while remaining interconnected with the case by a flexible conduit.

Abstract: An electromagnetic mechanical pulser implements a transverse wave metallic comb stripline TWMCS kicker having inwardly opposing teeth structured to retard a phase velocity of an RF traveling wave propagated therethrough to match the kinetic velocity of a continuous electron beam simultaneously propagated therethrough. The kicker imposes transverse oscillations onto the beam, which is subsequently chopped into pulses by an aperture. The RF phase velocity is substantially independent of RF frequency and amplitude, thereby enabling independent tuning of the electron pulse widths and repetition rate. The exterior surface of the kicker is conductive, thereby avoiding electron charging. In embodiments, various elements of the kicker and/or aperture can be mechanically varied to provide further tuning of the pulsed electron beam. A divergence suppression section can include a mirror TWMCS and/or magnetic quadrupoles.

Abstract: A technique for controlling and compensating the energy spread of a charged particle beam is provided. This technique is based on a passive dielectric-loaded structure that redistributes the energy within the bunch by means of the wakefield generated in the structure. Cylindrical and planar structure configurations are provided and also means for electrical and mechanical tuning to optimize performance. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

Abstract: A technique is presented to extract electromagnetic radiation from a dielectric loaded waveguide consisting of a layer or layers of dielectric material enclosed in a metallic conducting jacket. The electromagnetic radiation generated in the dielectric waveguide by a charged particle beam or otherwise generated as input to the waveguide. Dielectric loaded waveguides used for generation (or transport) of electromagnetic radiation at frequencies above 100 GHz have dimensions in the sub-mm range. Due to difficulty in the fabrication of a conventional broadband horn-like antenna to extract electromagnetic radiation from the structure because of the large impedance mismatch between the dielectric loaded waveguide and free space, the designing and fabricating aperture of antennas are formed as part of the dielectric waveguide and utilizes an angle cut or a set of apertures machined into the dielectric loaded waveguide to ensure broadband power extraction with minimal return loss and high directivity.

Abstract: A dielectric loaded accelerator for accelerating charged particles, such as electrons, ions and/or protons, is described herein. The dielectric loaded accelerator accelerates charged particles along a longitudinal axis and towards an outlet of the accelerator. The dielectric loaded accelerator accelerates the charged particles using oscillating electromagnetic fields that propagate within the accelerator according to an electromagnetic mode. The dielectric loaded accelerator described herein includes an electromagnetic mode with a phase velocity that increases towards the outlet of the accelerator and matches a velocity of the charged particles being accelerated along the longitudinal axis of the accelerator. By matching the phase velocity of the oscillating electromagnetic fields to the velocity of the charged particles, the accelerator reduces phase slippage between the fields and the charged particles and, therefore, efficiently accelerates charged particle towards the outlet.

Abstract: A technique for producing a coherent beam of hard X-rays is provided. This technique is based on a short wavelength undulator that uses the fields of an electromagnetic wave to deflect a relativistic electron beam along a sinusoidal trajectory in order to cause it to emit X-rays. The undulator consists of a slow-wave structure that is energized by a second counterpropagating electron beam. Cylindrical and planar structure configurations are provided and also a mechanism for electrical and mechanical tuning to allow control over the wavelength of the emitted X-ray beam.

Abstract: A dielectric loaded accelerator for accelerating charged particles, such as electrons, ions and/or protons, is described herein. The dielectric loaded accelerator accelerates charged particles along a longitudinal axis and towards an outlet of the accelerator. The dielectric loaded accelerator accelerates the charged particles using oscillating electromagnetic fields that propagate within the accelerator according to an electromagnetic mode. The dielectric loaded accelerator described herein includes an electromagnetic mode with a phase velocity that increases towards the outlet of the accelerator and matches a velocity of the charged particles being accelerated along the longitudinal axis of the accelerator. By matching the phase velocity of the oscillating electromagnetic fields to the velocity of the charged particles, the accelerator reduces phase slippage between the fields and the charged particles and, therefore, efficiently accelerates charged particle towards the outlet.

Abstract: An active device is provided that is energized by an optical source and uses an active paramagnetic medium to transfer this energy to a resonant circuit enabling new classes of electronic components.