Abstract: A particle accelerator for creation of a bunched particle beam and a method for the operation of such a particle accelerator are provided, wherein the particle accelerator includes an HF source and a directional coupler for splitting HF power of the HF source of an HF side into at least a first and a second HF power coupler of a cavity side for coupling in the HF power into at least one accelerator cavity. A non-reciprocal phase shifter is inserted on the cavity side between the directional coupler and the second HF power coupler, and an HF load is connected on the HF side to the directional coupler, where the non-reciprocal phase shifter is configured to pass a reflected HF wave of the second HF power coupler with phase delay in the direction of the directional coupler in such a way that a destructive interference of the reflected HF waves of the first and second power couplers occurs in the directional coupler in the direction of the HF source on the HF side.

Abstract: When using micro-resonant structures, a resonant structure may be turned on or off (e.g., when a display element is turned on or off in response to a changing image or when a communications switch is turned on or off to send data different data bits). Rather than turning the charged particle beam on and off, the beam may be moved to a position that does not excite the resonant structure, thereby turning off the resonant structure without having to turn off the charged particle beam. In one such embodiment, at least one deflector is placed between a source of charged particles and the resonant structure(s) to be excited. When the resonant structure is to be turned on (i.e., excited), the at least one deflector allows the beam to pass by undeflected. When the resonant structure is to be turned off, the at least one deflector deflects the beam away from the resonant structure by an amount sufficient to prevent the resonant structure from becoming excited.

Abstract: We describe an ultra-small resonant structure that produces electromagnetic radiation (e.g., visible light) at selected frequencies that can also be used or formed in conjunction with passive optical structures. The resonant structure can be produced from any conducting material (e.g., metal such as silver or gold). The passive optical structures can be formed from glass, polymer, dielectrics, or any other material sufficiently transparent using conventional patterning, etching and deposition techniques. The passive optical structures can be formed directly on the ultra-small resonant structures, or alternatively on an intermediate structure, or the passive optical structures can be formed in combination with other passive optical structures.

Abstract: An electronic transmitter or receiver employing electromagnetic radiation as a coded signal carrier is described. In the transmitter, the electromagnetic radiation is emitted from ultra-small resonant structures when an electron beam passes proximate the structures. In the receiver, the electron beam passes near ultra-small resonant structures and is altered in path or velocity by the effect of the electromagnetic radiation on structures. The electron beam is accelerated within a series of spiral-shaped anodes to an appropriate current density without the use of a high power supply. Instead, a sequence of low power levels is supplied to the sequence of anodes in the electron beam path. The electron beam is thereby accelerated to a desired current density appropriate for the transmitter or receiver application without the need for a high-level power source.

Abstract: A magnet configuration for a power microwave tube with a resonant cavity comprises a permanent magnet (110) with an axis-aligned through-bore (135) of sufficient size to contain the resonant cavity. The permanent magnet has an inner chamber (140) that is centered on the axis (130) with opposite magnet poles aligned along the axis. The magnet configuration further comprises an electromagnet coil (120) fitting in the chamber and encircling the axis such that the coil produces a magnetic field that reinforces the magnetic field from the permanent magnet. An optional protrusion (125) spanning the through-bore narrows an air gap between the poles. The method provides a magnetic field in a power microwave generator by combining a permanent magnet with an electromagnet in accordance with the magnet configuration and energizes the electromagnetic coil, which may be by pulsing the coil current.

Abstract: The invention relates to a microwave power tube consisting of an electron gun comprising a cathode that generates an electron beam in a microwave structure of the tube, and a collector for collecting electrons from the beam. In addition, the tube comprises a magnetic device for spreading the beam in the collector, which generates a periodic amplitude-modulated magnetic spread field Bblm. The invention is suitable for microwave power tubes.

Abstract: We describe an ultra-small structure that produces visible light of varying frequency, from a single metallic layer. In one example, a row of metallic posts are etched or plated on a substrate according to a particular geometry. When a charged particle beam passed close by the row of posts, the posts and cavities between them cooperate to resonate and produce radiation in the visible spectrum (or even higher). A plurality of such rows of different geometries can be etched or plated from a single metal layer such that the charged particle beam will yield different visible light frequencies (i.e., different colors) using different ones of the rows.

Abstract: An electronic transmitter or receiver employing electromagnetic radiation as a coded signal carrier is described. In the transmitter, the electromagnetic radiation is emitted from ultra-small resonant structures when an electron beam passes proximate the structures. In the receiver, the electron beam passes near ultra-small resonant structures and is altered in path or velocity by the effect of the electromagnetic radiation on structures. The electron beam is accelerated to an appropriate current density without the use of a high power supply. Instead, a sequence of low power levels is supplied to a sequence of anodes in the electron beam path. The electron beam is thereby accelerated to a desired current density appropriate for the transmitter or receiver application without the need for a high-level power source.

Abstract: We describe an ultra-small resonant structure that produces electromagnetic radiation (e.g., visible light) at selected frequencies. The resonant structure can be produced from any conducting material (e.g., metal such as silver or gold). In one example, a number of rows of posts are etched or plated on a substrate, with each row having a particular geometry associated with the posts and cavities between the posts. A charged particle beam is selectively directed close by one of the rows of posts, causing them to resonate and produce radiation (e.g., in the visible spectrum at a predominant frequency). Directing the charged particle beam at a different row yields radiation at a different predominant frequency.

Abstract: When using micro-resonant structures, it is possible to use the same source of charged particles to cause multiple resonant structures to emit electromagnetic radiation. This reduces the number of sources that are required for multi-element configurations, such as displays with plural rows (or columns) of pixels. In one such embodiment, at least one deflector is placed in between first and second resonant structures. After the beam passes by at least a portion of the first resonant structure, it is directed to a path such that it can be directed towards the second resonant structure. The amount of deflection needed to direct the beam toward the second resonant structure is based on the amount of deflection, if any, that the beam underwent as it passed by the first resonant structure. This process can be repeated in series as necessary to produce a set of resonant structures in series.

Abstract: A drift tube linear accelerator (linac) that can be used for the acceleration of low energy ion beams. The particles enter the linac at low energy and are accelerated and focused along a straight line in a plurality of resonant accelerating structures interposed by coupling structures up to the desired energy. In the accelerating structures, excited by an H-type resonant electromagnetic field, a plurality of accelerating gaps is provided between drift tubes supported by stems, for instance alternatively horizontally and vertically disposed. A basic module composed of two accelerating structures and an interposed coupling structure, or a modified coupling structure connected to a RF power generator, is if necessary linked to a vacuum system and equipped with one or more quadrupoles.

Abstract: A multiple beam linear accelerator system and method where two or more accelerator waveguides are driven by a single high power microwave source. A single RF power system is multiplexed to drive the plurality of accelerator waveguides. Each accelerator waveguide is addressed at a different RF frequency, and the microwave source generates pulses at the appropriate RF frequency for each accelerator waveguide on a pulse-by-pulse basis.

Abstract: An electron beam tube such as a klystron includes a penultimate resonant cavity (22) located before the output cavity (14). The penultimate resonant cavity (22) is arranged to be inductively coupled, being resonant at a frequency which is slightly greater than a harmonic frequency. This provides increased sharpening of bunches of electrons arriving at the output cavity (14) giving increased efficiency at the output.