SU69060A1 - Electronic lamp - Google Patents

Description

The present invention is about a method of reducing thermoelectronic emission from the surface of electrodes of vacuum electrodes with complex activated cathodes (containing metals such as barium, calcium and strontium, for example) and. in particular, the so-called oxide cathodes.

This invention is of particular importance for generator, modulator and amplifier lamps, as well as for thyratrons. As is well known, in these lamps the grid, which is rather close to the cathode and considerably heating from it, is gradually covered with the products of its evaporation, in particular, with barn. By virtue of this, the work of the departure of the grid decreases, as a result of which the thermoelectronic EPSA of the latter increases.

The presence of a large thermoelectric EM (Css grid degrades the quality of the lamp, as this entails the appearance of high conductivity. Between the grid and the anode, as well as the reverse current, an extremely undesirable application of the grid circuit.

However, in thyratrons, the thermal emission of the grid causes a spontaneous ignition of the discharge, which disrupts the operation of the apparatus.

The elimination of thermionic emission presents significant difficulties.

If one proceeds along the path of decreasing the temperature of the grid, then it will have to increase the standing of the gap between the grid and the cathode. However, this is undesirable, since from an increase of 1a between n11 eats;. ;;); and. The cathode sharply imposes the steepness of the lamp characteristic, which leads to a decrease in its efficiency. A decrease in the cathode temperature leads to a decrease in its efficiency and electron emission.

The reduction of thermionic emission from the surface of the e.1. Electrode occurs when the electrodes are coated. R, in particular, grids, veins: which bind the evaporation products of the cathode deposited on it. For

JMo 69060-2 such a coating already knows the use of the elements of the 1st "3rd group of the periodic table both in pure nida, for example, zirconium tantalum, gold, silver, and in the form of oxides, for example, in the form of oxides of titanium, chromium and vanad and

According to the present invention IB, salts of heavy metals (for example, nickel, copper, iron, etc.) of silicic, tungsten or boric acids are used to coat such a network.

These salts, at a temperature of 400 ° C, are reacted with barium and chemically bound.

An example of such a reaction is the reaction of tungstate with barium: In the case of CuWO4-fBa BaWO4-fCu.

Another example is the reaction of nickel silicate and barI according to the same formula with the following process: preparing a salt of juremnic acid precipitation of m from 10% sodium silicate solution: and 10% nickel nitrate solution, in 10% HiOM excess based on NiSiOs, followed by multiple decantation followed by drying at 250 °. The salt is then carefully ground in an agate mortar or ball mill with a 2-fold weight of 3% solution of low-viscosity cellulose in amyl acetate, and after grinding with another amount of amyl acetate, the prepared suspension is sprayed on using a sprayer or other method. electrode surface.

After such a treatment, the e.Missy thermal specimen, when heated to a temperature of 1750, drops from 16-W micro- meter to zero.

Subject invention

An electron tube in which the grid is coated with substances that bind evaporation products of a cathode made of alkaline-earth metals deposited on it, characterized by the fact that salts of heavy metals (for example, nickel, copper, iron) are used as B-type H1 substances. et al.) silicic, tungstic or boric acids.