Abstract:
Die Erfindung betrifft eine Vorrichtung und ein Verfahren zum Beaufschlagen von einem gasförmigen Medium mit beschleunigten Elektronen mittels eines Elektronenstrahlerzeugers, welcher mindestens eine Kathode (107) zum Emittieren von Elektronen und mindestens ein Elektronenaustrittsfenster (104; 304) aufweist, wobei a) die mindestens eine Kathode (107) ringförmig und das mindestens eine Elektronenaustrittsfenster (104; 304) als ringförmiger erster Hohlzylinder ausgebildet wird, wobei das ringförmige als erster Hohlzylinder ausgebildete Elektronenaustrittsfenster (104; 304) eine Innenwandung eines ringförmigen Gehäuses (101;301) des Elektronenstrahlerzeugers bildet, wobei die von der Kathode (107) emittierten Elektronen zur Ringachse (103; 303) des ringförmigen Gehäuses (101; 301) beschleunigt werden; b) innerhalb des als erster Hohlzylinder ausgebildeten Elektronenaustrittsfensters (104; 304) ein ringförmiger zweiter Hohlzylinder (112; 312) angeordnet wird, welcher einen ringförmigen Raum (113; 313) zwischen dem ersten Hohlzylinder und dem zweiten Hohlzylinder (112; 312) begrenzt; c) ein Kühlgas durch den ringförmigen Raum (113; 313) zwischen dem ersten Hohlzylinder und dem zweiten Hohlzylinder (112; 312) geführt wird und d) das mit beschleunigten Elektronen zu beaufschlagende gasförmige Medium durch den zweiten Hohlzylinder (112; 312) geführt wird.
Abstract:
The present invention describes a field-emitter array cathode structure with two stacked control electrodes and their driving method to produce short electron pulses. A sequence of electric stimuli applied to the field emitter array drives generates an electron beam with precisely controlled emission angle, allowing for the production of short collimated electron pulses with high electron beam brightness.
Abstract:
The invention relates to an apparatus for generating a plurality of charged particle beamlets, comprising a charged particle source for generating a diverging charged particle beam, a converging means for refracting said diverging charged particle beam and a lens array comprising a plurality of lenses, wherein said lens array is located between said charged particle source and said converging means. In this way, it is possible to reduce aberrations of the converging means.
Abstract:
An electron beam device for applying a primary electron beam onto a sample, and detecting a secondary electron beam produced from a sample surface by the irradiation to evaluate the sample surface, characterized in that the cathode of an electron gun for emitting primary electron beam have a plurality of emitters disposed at intervals on one circle centered on the optical axis of a primary electron optical system and emitting a primary electron beam, and the plurality of emitters are disposed so that points projected on a line parallel to the scanning direction of the primary electron beam are arranged at equal intervals.
Abstract:
The electronic gun intended for the shaping of materials, particularly for the production of printing blocks, comprises a heated cathode (1), a perforated anode (3) and an auxiliary electrode (2) brought to a negative potential higher than that of the cathode. The beam current is determined by the dimension of the active surface (11) of the cathode and the heating regulation of the cathode at a constant temperature.
Abstract:
An ion source and a method of extracting and accelerating ions are provided. The ion source includes a chamber. The ion source further includes a first hollow cathode having a first hollow cathode cavity and a first plasma exit orifice and a second hollow cathode having a second hollow cathode cavity and a second plasma exit orifice. The first and second hollow cathodes are disposed adjacently in the chamber. The ion source further includes a first ion accelerator between and in communication with the first plasma exit orifice and the chamber. The first ion accelerator forms a first ion acceleration cavity. The ion source further includes a second ion accelerator between and in communication with the second plasma orifice and the chamber. The second ion accelerator forms a second ion acceleration cavity. The first hollow cathode and the second hollow cathode are configured to alternatively function as electrode and counterelectrode to generate a plasma.
Abstract:
A charged particle propagation apparatus comprising a generator comprising a vacuum chamber with a gun therein for discharging a charged particle beam from within the vacuum chamber and out of the vacuum chamber through a beam exit disposed in a wall of the vacuum chamber. The apparatus further comprises a higher pressure region adjoining the vacuum chamber at the beam exit that is maintainable at a pressure greater than a pressure of the vacuum chamber and a plasma interface disposed at the beam exit comprising a plasma channel. The plasma channel is aligned with the beam exit, has a first end and a second end and has at least three electrode plates disposed between the first end and the second end. The apparatus further comprises a control system adapted to apply a sequence of electrical currents to the electrode plates. The sequence of electrical currents is configured to cause at least one plasma to move from the first end to the second end of the plasma channel thereby pumping down the beam exit, and, in use, the charged particle beam is propagated from the vacuum chamber through the, or each, plasma in the plasma channel and into the higher pressure region.
Abstract:
The invention relates to a cathode arrangement (20) comprising: a cathode body housing an emission surface (32) for emitting electrons in a longitudinal direction (Z), wherein the emission surface is bounded by an emission perimeter (35); a focusing electrode (40) at least partially enclosing the cathode body in a transversal direction and comprising an electron transmission aperture (44) for focusing the electrons emitted by the emission surface, wherein the aperture is bounded by an aperture perimeter (45), wherein the cathode body is moveably arranged within the focusing electrode over a maximum transversal distance (d1) from an aligned position (R0), and wherein the aperture perimeter transversally extends over the emission surface and beyond the emission perimeter over an overlap distance (d2) that exceeds the maximum transversal distance.
Abstract:
A charged particle emitting assembly comprises an emitter member (5) for emitting charged particles of one polarity. A tubular shield electrode (6) circumferentially surrounds the emitter member and is held in use at the same polarity as the charged particles. A tubular accelerating electrode (7) is positioned substantially coaxially with the shield electrode (6) and is held in use at the opposite polarity to the shield electrode. The arrangement is such that charged particles from the emitter member (5) initially spread laterally outwardly and then are focused into a beam which passes through the tubular accelerating electrode (7).