Method for inhibiting grid emission of pulsed travelling wave tube

Abstract

The invention discloses a method for inhibiting grid emission of a pulsed travelling wave tube, relates to a microwave electric vacuum technology, and states an improvement measure for effectively inhibiting grid thermionic emission (grid emission for short) of the pulsed travelling wave tube, namely a novel hafnium (Hf) material is used as the material of a grid net in a pulsed travelling wave tube electronic gun. The metal has the properties of high work function, low secondary electron yield and high melting point / low saturated steam pressure; and a diode test and tests of physical analysis, tube preparation application and the like of the metal show that the hafnium metal foil serving as a grid net substrate material can inhibit grid emission of the conventional pulsed travelling wave tube during the operating life, so that the operating reliability and the operating stability of the grid-controlled pulsed travelling wave tube is powerfully guaranteed.

Description

technical field [0001] The invention relates to the field of microwave electric vacuum technology, and relates to a method for suppressing grid emission of a pulse traveling wave tube, which realizes the goal of suppressing grid thermionic emission and improves the working reliability and stability of the pulse traveling wave tube. Background technique [0002] At present, grid-controlled pulse traveling wave tubes are widely used in key national defense projects such as radar and electronic countermeasures. Emitting, so that the traveling wave tube works in a pulse modulation state with a certain pulse width and repetition frequency, and realizes pulse output with high peak power. [0003] In the electron gun of the grid-controlled pulse traveling wave tube, the grid is used to play the role of the control electrode. The control electrode itself should not emit electrons. If the control electrode emits electrons, it will disturb the injection of electrons emitted from the c...

AI Technical Summary

Problems solved by technology

[0003] In the electron gun of the grid-controlled pulse traveling wave tube, the grid is used to play the role of the control electrode. The control electrode itself should not emit electrons. If the control electrode emits electrons, it will disturb the injection of electrons emitted from the cathode. The laminar flow of the traveling wave tube will deteriorate the laminar flow of the electron beam, or cause the modulator to fire. work reliability and stability

At present, molybdenum (Mo) is used as the grid material in grid-controlled pulse traveling wave tubes. This is because molybdenum not only has the characteristics of high-temperature electric vacuum materials, but also has good plastic processing performance. Extreme thermal electron emission phenomenon, causing the transmitter to malfunction and fail

At present, the measure usually taken for this phenomenon is to modify the surface of the molybdenum-based grid, that is, to add a layer of anti-emission film (such as C, Au, Hf, Pt, etc.) To a certain extent, the grid emission phenomenon is improved, but there is a problem of weak bonding between the surface-modified film and the substrate, and there is a phenomenon of shedding, so secondary problems will occur and affect the reliability and stability of the pulse traveling wave tube.

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