Preparation method of cathode heater assembly with high power and long service life

Abstract

The invention discloses a preparation method of a cathode heater assembly with high power and long service life. The preparation method comprises the following steps: using a rhenium tungsten wire toprepare a double-end double-screw cylinder heater prefabticated member; putting the double-end double-screw cylinder heater prefabticated member on a half-cylinder heater forming die to form a double-end double-screw cylinder heater; putting the double-end double-screw cylinder heater into a circular ring cavity die and uniformly arranging screw pitches to be bent into a circular heater prefabticated member; carrying out blackening, insulating layer coating and sintering treatment on the heater prefabticated member in sequence to form a required heater; enabling the space of a cathode and theheater to be filled with a ceramic filler; and then sintering to prepare the cathode heater assembly. By adopting the double-end double-screw ring structure, the problem, that the temperature distribution in the axial direction of the cathode is nonuniform caused by a cold side effect at two ends of the cathode, of a previous double-screw filament cathode is overcome, the temperature distributionon the surface of the cathode is uniform, and the operating point temperature of the cathode can be reduced; and according to the prepared cathode heater assembly, the starting time for cathode operation can be shortened by about one half, and the heating efficiency of the cathode is reduced.

Description

technical field [0001] The invention relates to the field of high-power vacuum electronic devices, in particular to a method for preparing a high-power and long-life cathode heater assembly. Background technique [0002] In the prior art, there are single-helix, double-helix, folded and coiled-type structures for cathode heaters in high-power vacuum electronic devices. When looking for the cause of the end of the life of high-power vacuum electronic devices, it is usually not due to the exhaustion of active materials, but the damage of the hot wire, which is due to the magnetic field generated by the alternating thermal sub-power supply and the axial magnetic field of the vacuum electronic device. The interaction causes the hot wire to be subjected to an alternating mechanical force. Obviously, the greater the current of the heating wire, the greater the interaction force, the greater the vibration frequency of the heating wire, the easier it will be damaged after long-term...

AI Technical Summary

Problems solved by technology

Although the design structure of the cathode heater later adopts double helix, folded type and coil type, which has certain effects on vacuum electronic devices with low power and life requirements, but for high power and long life vacuum electronic devices, there is no fundamental to improve and enhance

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