Abstract: Cavity resonators have a multitude of applications in radio-frequency, microwave, and vacuum electronics. Cavity resonators are used as frequency selective filters and oscillators. In vacuum electronic devices and charged particle accelerators cavities are used to couple energy into and out of charged particle beams. Typically cavity resonators are optimized for single mode operation and are limited to sinusoidal waveforms and interactions. Harmonic cavities have many of the same applications, but because they resonate many axially symmetric harmonic modes simultaneously, the superposition of these modes is an on-axis arbitrary waveform. Harmonic cavities have both passive and active applications. When a periodic charged particle beam passes through a harmonic cavity whose resonances are at the same frequency as the beam's periodicity, the beam induces these cavity modes to resonate. The superposition of these modes, on axis, has a voltage vs. time waveform that ideally mirrors the current vs.

Abstract: A closed drift ion source is disclosed. The ion source has an open end 1 and a central axis 150 around which are arranged outer magnetic pole piece 3, inner magnetic pole piece 5, anode 2, shield 6 and back magnetic shunt 17. In one embodiment the anode 2 and inner magnetic pole piece 5 are annular. Permanent magnets 7 are located behind the shield 6 and in contact with outer magnetic pole piece 3 and the back magnetic shunt 17. As a result the magnetic field lines pass through the magnetic pole pieces and a mirror magnetic field is set up in the discharge region between them. The inner magnetic pole piece 5 is hollow which facilitates production of the mirror magnetic field.

Abstract: The specification describes a method and apparatus for electron beam lithography wherein a Wehnelt electron gun is modified to improve the uniformity of the electron beam. The bias on the Wehnelt aperture is reversed from the conventional bias so that it is biased positively with respect to the cathode. The Wehnelt opening is tapered with a disk emitter inserted into the taper. The result of these modifications is an electron beam output with low brightness which is highly uniform over the beam cross section.

Abstract: An enhanced electron source in most respects similar to a standard cathode assembly for an electron gun includes an electron emitter surrounded by a suppressor electrode, the emitted electrons passing through an extractor electrode. Additionally, the suppressor electrode includes a small ring shaped permanent magnet surrounding the opening in the suppressor electrode through which the emitter tip protrudes. The resulting magnetic field is aligned with the beam axis, and includes a tail which forms a very short focal length magnetic lens immediately following the emitter tip. This magnetic field collimates the electron beam before it enters the downstream electrostatic gun lens, thus increasing the effective angular intensity of the cathode assembly. The aberrations of this collimating lens are very low so that its useful brightness is not reduced. Also the influence of guns lens aberrations is reduced because a smaller aperture angle in the gun lens may be used to obtain higher beam current.

Abstract: The disclosure relates to electron guns comprising several electrodes, including a plurality of cathodes designed for the production, from an emissive face, of an electron beam each. Each of the cathodes is surrounded by a pole piece. This pole piece is designed to convey a magnetic flux close to the emissive face of the cathode. Application to longitudinal-interaction multibeam electron tubes.

Abstract: A light-transmissive and transparent film photocatalyst made of one of anatase-type titanium dioxide and alpha iron oxide is formed on an outside surface of a glass tube used for a fluorescent lamp. The thin film photocatalyst is formed so that electrons and holes generated inside the film by light irradiation can easily and rapidly move to the surface of the film and generate various active species at the surface of the film by contacting with the room air, enabling an excellent deodorization effect, bactericidal and fungicidal activity and contamination preventing effect.

Abstract: An electron beam generator includes: an electron emitting cathode (1); an anode (3) with an anode bore (4) for the passage of an electron beam (6); a Wehnelt electrode (2) between the cathode (1) and the anode (3) for controlling the electron beam; the cathode (1); the anode (3) and the Wehnelt electrode (2) disposed within a vacuum chamber (100); and a magnetic unit (7) disposed between the cathode (1) and the anode (3) for generating a static transverse magnetic field causing the electrons to be deflected along a curved path until the electrons enter the anode (3) such that ions follow an ionic path back to strike the Wehnelt electrode (2) and are kept from striking the cathode (1) by displacement caused by the ionic path. The present invention reduces the number of ions that impact the cathode and reduces the number of ions that are formed by the ionization of residual molecules, increasing the service life of the cathode.