JPS6065423A - Electron emitter and production process thereof and activation process of said electron emitter - Google Patents

Abstract

PURPOSE:To enable an electron emitter of long life time to be produced in a simple process, by forming a metallic film on the holes of the surface of a porous supporting body, making oxide powder for emitting electrons to stick onto said metallic film, and then heating and melting said metallic film in fluidified form. CONSTITUTION:A gold film 12 is vacuum evaporated on the surface part of a porous supporting part 10, for instance, on thin holes 10A with diameters of about 10-20mum. Oxide powder, for instance, made of barium oxide whose particle diameter is about 1-5mum is suspended in a collodion acting as a binder, and this collodion is packed into the thin holes 10A on which said film 12 has been deposited. The porous supporting body 10 of the electron emitter with such constitution is heated by a heater or the like, for instance, up to about 800 deg.C. Thereby, electrons are emitted from the oxide powder. Consequently, the electron emitter of long life time can be produced in a simple process.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an 11-electron emitter with a long life, a method for manufacturing the same, and a method for activating the electron emitter.

[Prior Art] ゛An electron emitter is used as a cathode of an electron tube, and a conventional resistive-impregnated electron emitter, as shown in FIG. It has a porous support 10 made of, for example, tungsten, whose surface layer is impregnated, a heater 22 for heating the porous support 10, and a sleeve 33 that supports the porous support 11 and houses the heater 22 inside.

By means of the heater 22, the porous support 1o is
It is heated to a temperature of around 00'c and electrons are emitted from it.

However, in such an electron emitter,
By use, as shown in FIG.
When the oxide powder 11B on the surface of the oxide powder 11B deteriorates, the electron emitting ability decreases even though the oxide powder 11A inside it is healthy, resulting in a disadvantage that the life as an electron emitter is shortened. .

[Purpose] Therefore, the purpose of the present invention is to eliminate the above-mentioned drawbacks, and to
The objective is to provide an electron emitter with a long lifetime.

Another object of the present invention is to provide a method for manufacturing such an electron emitter using simple steps.

Still another object of the present invention is to provide a method for easily activating electron emitters.

[Structure of the Invention] The present invention provides a porous support, a metal film formed on the pores on the surface of the porous support, an electron-emitting oxide powder shielded by the metal film, and a metal. and a heating means for heating and melting the film to make it flow.

In the production method of the present invention, the pores on the surface of the porous support are made of gold 1411Q! is formed, and an electron-emitting oxide powder is placed on the metal crotch.

Furthermore, in the activation method of the present invention, a porous support, a metal 11 plane formed on the pores on the surface of the porous support, an electron-emitting oxide powder stuck on the metal crotch, and a metal/film When activating an electron emitter equipped with a heating means for melting and fluidizing the metal film, the metal film is melted and fluidized, and the oxide powder is moved along with the fluidization.
Activates the electron emission ability of oxide powder.

[Example] The present invention will be described in detail below with reference to the drawings.

FIG. 3(A) is an enlarged cross-sectional view showing a main part of an embodiment of an electron emitter according to the present invention, and since the other parts in this embodiment are the same as in FIG. 1, illustration thereof is omitted. . In FIG. 3(A), parts similar to those in FIGS. 1 and 2 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

In FIG. 3(A), IOA is a pore with a diameter of, for example, about 10 to 20 gm on the surface of the porous support 10, and 12 is a gold crotch deposited in vacuum on the surface of the pore 10A. For example, an oxide powder 11 made of barium oxide and having a particle size of about 1 to 5 μm is suspended in collodion as a binder, and then the membrane 12 is inserted into the pores 10A. Fill it inside. For convenience, oxide powder 11
In FIG. 3(A), the oxide powder on the outermost surface of the layer is designated by the symbol 11B, and the oxide powder located below it is designated by the symbol 11.
Indicated by A.

In an electron emitter with such a configuration, the porous support lO is heated to, for example, 800°C+i11 by a heater.
Heat to the following temperature. This allows the oxide powder to be
One child is released.

When the electron emitting ability of the oxide powder 11 deteriorates, the porous support 10 is heated to 1064° C. or higher using a heater to melt the gold film 12. As a result, since the oxide powder 11 has poor wettability with respect to molten gold and has a low specific gravity, the oxide powder 11 becomes floating on the surface of the molten gold above the pores 1OA.

- The gold flows through the pores 10A by capillary action, and the oxide powder 11 also flows, and the powder 1 that was previously under the powder 11B on the surface/surface of the oxide powder 11 layer flows.
1A is exposed at the surface of the layer as shown in FIG. 3(B).

Therefore, I lowered the power of the heater and added oxide powder 11.
If the temperature is maintained at around 800°C, for example, the electron emission ability is restored and a stable electron flow can be obtained.

Note that materials with low vapor pressure, ie metals such as indium and tin, can also be used instead of gold.

[Effects] As explained above, according to the present invention, a long-life ladle electron emitter can be obtained.

Furthermore, according to the present invention, the electron emitter can be constructed with two rods inside the cylinder.

Furthermore, according to the present invention, the metal film formed on the pores of the porous support is heated above its tumor point to melt and flow, whereby the inner portion of the layer of oxide powder is heated. By exposing the oxide powder on the surface, the electron emitting ability, which has once decreased, can be reactivated.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the principle of a conventional oxide-impregnated electron emitter, Figure 2 is an enlarged cross-sectional view of the main part of the same electron emitter, and Figures 3 (A) and (B) are the invention of the present invention. 6 is a cross-sectional view showing an enlarged main part of Example of Nigaru electron emitter 10... porous support, 1 (IA... pores, 11, IIA, IIB... oxidation Material powder, 12...gold film, 22...heater, 33...sleeve. Patent applicant: Nippon Telegraph and Telephone Public Corporation representative, patent attorney Yoshi Tani - Figure 2

Claims (1)

[Scope of Claims] 1) A porous support, a bud membrane formed on the pores on the surface of the porous support, and an electron-emitting oxide powder stuck on the metal ++a; An electron emitter comprising heating means for heating and melting the metal 11 to make it flow. 2) A method for producing an electron emitter, comprising: forming a metal film on the pores on the surface of a porous support; and disposing an electron-emitting oxide powder on the rt+4 metal Ws film. 3) A porous support, a metal film formed on the pores on the surface of the porous support, an electron-emitting oxide powder deposited on the metal film, and the metal 11 are heated and melted. ．． When activating the emitter including a heating means for making the metal film flow, the metal film is melted by heating and made to flow, which moves the oxide powder along with the t-movement and causes the oxide powder to flow. A method for activating an electron emitter characterized by activating the electron emitting ability of a substance powder. (Hereafter, margin)