Abstract:
Switching and switchover devices for DC networks make it possible to realize, particularly in the event of faults, rapid and reliable switching processes in combination with good overvoltage damping and low energy losses during normal operation. The switching devices furthermore have short turn-off times and require no cooling since they have no on-state power losses during normal operation.
Abstract:
Switching and switchover devices for DC networks make it possible to realize, particularly in the event of faults, rapid and reliable switching processes in combination with good overvoltage damping and low energy losses during normal operation. The switching devices furthermore have short turn-off times and require no cooling since they have no on-state power losses during normal operation.
Abstract:
Methods and systems to compensate for distortions created by dynamic voltage applied to an electron multiplier used in mass spectrometry. An electron multiplier has a cathode end accepting ion flow, an opposite emitter end and an interior surface. The electron multiplier produces an electron output from ions colliding with the interior surface. A variable power supply has a voltage output coupled to the cathode end and the emitter end of the electron multiplier. The voltage output changes dynamically to adjust the electron output from the electron multiplier. An anode is located in proximity to the electron multiplier. An electrometer is coupled to the anode in proximity to the electron multiplier to measure the current generated by the electron output. A low pass filter circuit is coupled to the emitter end to the ground of the electrometer to attenuate emitter voltage changes. A bias circuit is coupled to the emitter end to stabilize emitter to anode voltage difference.
Abstract:
Methods and systems to compensate for distortions created by dynamic voltage applied to an electron multiplier used in mass spectrometry. An electron multiplier has a cathode end accepting ion flow, an opposite emitter end and an interior surface. The electron multiplier produces an electron output from ions colliding with the interior surface. A variable power supply has a voltage output coupled to the cathode end and the emitter end of the electron multiplier. The voltage output changes dynamically to adjust the electron output from the electron multiplier. An anode is located in proximity to the electron multiplier. An electrometer is coupled to the anode in proximity to the electron multiplier to measure the current generated by the electron output. A low pass filter circuit is coupled to the emitter end to the ground of the electrometer to attenuate emitter voltage changes. A bias circuit is coupled to the emitter end to stabilize emitter to anode voltage difference.
Abstract:
A photocathode high-frequency electron-gun cavity apparatus of the present invention is provided with a high-frequency acceleration cavity (1), a photocathode (8, 15), a laser entering port (9), a high-frequency power input coupler port (10), and a high-frequency resonant tuner (16). Here, the apparatus adopts an ultra-small high-frequency accelerator cavity which contains a cavity cell formed only with a smooth and curved surface at an inner face thereof without having a sharp angle part for preventing discharging, obtaining higher strength of high-frequency electric field, and improving high-frequency resonance stability. Further, the photocathode is arranged at an end part of a half cell (5) of the high-frequency acceleration cavity for maximizing electric field strength at the photocathode face, perpendicular incidence of laser is ensured by arranging a laser entering port at a position facing to the photocathode behind an electron beam extraction port of the high-frequency acceleration cavity for maximizing quality of short-bunch photoelectrons, and a high-frequency power input coupler port is arranged at a side part of the cell of the high-frequency acceleration cavity for enhancing high-frequency electric field strength. According to the above, it is possible to provide a small photocathode high-frequency electron-gun cavity apparatus capable of generating a high-strength and high-quality electron beam.
Abstract:
The invention relates to switching and switchover devices for DC networks which make it possible to realize - particularly in the event of faults - rapid and reliable switching processes in combination with good overvoltage damping and low energy losses during normal operation.
Abstract:
RF field is sensed to produce an incoming voltage that drives a microarray of electron guns in a sweep pattern towards a detector array. The electron guns emit a beam current that may amplify the incoming voltage signal, and the detector material may be selected to amplify the beam current at the detector, for example, by avalanche and/or cascade in a Schottky material, to provide a low current, high gain amplification. The microarrays may be arranged in various combinations to produce successive amplifications, frequency multipliers, transmit-receive amplifiers, crossbar switches, mixers, beamformers, and selective polarization devices, among other such devices.