摘要:
An electron-emitting cathode (6) consists of an electricaly conducting emitter layer (7) attached to a side wall (2) and a gate (9) which is fixed at a mall distance inside a concave emitter surface of the emitter layer (7). The cathode (6) surrounds a reaction area (3) containing a cylindrical grid-like anode (5) and a central ion collector (4) which consists of a straight axial filament. An ion collector current (I IC ) reflecting the densitiy of the gas in the reaction region (3) is measured by a current meter (11) while a gate voltage (Vc) is kept between the ground voltage of the emitter layer (7) and a higher anode voltage (V A ) and is regulated in such a way that an anode current (T A ) is kept constant. The emitter layer (7) may comprise an array of metal, e.g., nickel or molybdenum tips or consist essentially of a semiconductor material like silicon, preferably coated by, e.g., carbide, diamond-like carbon or molybdenum, or of carbon nanotubes or it may be a roughened surface portion of the side wall surface. The gate (9) may be a grid or it may be made up of patches of metal film covering spacers distributed over the emitter area or a metal film covering an electron permeable layer placed on the emitter surface.
摘要:
In order to bring a high power vacuum tube to full power in a few seconds, it is necessary to heat the cathode quickly to 1100°C. In large tubes, prior art structures cannot be simply enlarged. A novel cathode structure (10) in which the heater element (14) is anisotropic pyrolytic graphite coated with anisotropic pyrolytic boron nitride for insulation and then sintered to the cathode avoids these problems.
摘要:
Bei einer steuerbaren Hochleistungs-Elektronenröhre in Form einer Tetrode wird die Anodengleichspannung bei einem Anodenwirkungsgrad von grösser 80% auf weniger als 10 kV reduziert. Mit einer solchen Röhre lassen sich AM-Rundfunksender realisieren, die sich bei weitgehend unverändertem Gesamtwirkungsgrad durch einen kompakten Aufbau auszeichnen.