SU408396A1 - SPECTRAL HIGH-INTENSITY LAMP - Google Patents

Description

one

The invention relates to gas discharge devices, in particular to spectral light sources emitting narrow spectral lines of various chemical elements. Such light sources are used in various spectrophotometric devices, for example, in devices for atomic absorption and atomic fluorescence analysis of the elemental composition of a substance.

Spectral lamps with a combined discharge of various designs are known. In particular, a lamp is known (ed. No. 264551), in which between the oxide cathode and the anode, which serve as an arc, discharge disk electrodes with a central hole, made of metals, whose spectrum is to be obtained, are placed.

The hole of each next from the oxide cathode of the disk electrode has a diameter larger than the diameter of the hole of the previous disk electrode. Between these disk electrodes and the anode, a glow discharge is ignited, which ensures a greater concentration inside the holes of the atomic vapor due to the effect of a hollow cathode. The excitation of this atomic vapor occurs in the nolol of the arc column of the arc discharge passing through the holes in the disk electrodes.

The described lamp with disk electrodes can be successfully implemented when creating spectral light sources with a combined discharge, receiving only

The spectra of chemical elements from which it is possible to manufacture disk electrodes and preserve their geometrical dimensions in the process of pumping out and training the lamp at the pumping station, which are the basic and necessary operations in the technological process of making the lamp. These elements include all metals with a melting and evaporation temperature not lower than 500 ° C.

However, such a design of disk elec- trodes does not allow for the creation of a spectral lamp with high durability. The reason for this is the spontaneous partial transfer of the glow discharge in the hollow cathode to the surface of the ceramic cup,

having a potential of a disk electrode, due to the formation of a conductive film of a dispersed material of a disk electrode on it (depending on the element) after 50-100 hours of operation.

The purpose of this invention, which is the further development of auth. St. No. 264551, is the creation of a spectral high-intensity lamp that radiates the spectrum of one or more of several low-melting or easily volatile chemical elements and their compounds with a strong high durability.

This is achieved by making in the disk electrodes through channels of variable cross section, spaced perpendicular to the side surface of the central opening of the disk electrode and filled with low-melting or easily volatile chemical elements or their compounds. Such an embodiment of disk electrodes provides for the creation of a high-intensity lamina with a long service life, allows one to obtain simultaneously the spectra of several easily volatile and low-melting elements and does not exclude the possibility of exciting the spectra of non-volatile elements.

FIG. 1 shows a spectral high-intensity lamp; in fig. 2 - one pz disk electrodes in the collection.

The lamp is a cylindrical glass flask 1 with a window 2 for exit of radiation made of a material that is transparent in the ultraviolet region of the spectrum. The anode 3, the effective thermal cathode 4 and the disk electrodes 5 are assembled on an eight-pin flat foot 6 using mica disks 7. To ignite a glowing discharge inside the holes of the disk electrodes and pass the arc through them, they are placed in the ceramic plates 8, and the conclusions of the foot are in insulating tubes 9.

In order to provide a convenient and convenient connection of the lamp electrodes to the power supply, the latter is equipped with a base 10 with dimensions and location of the pins under the standard lamp panel. To obtain a certain concentration of the atomic vapor of a low-melting or volatile chemical element in the body of the above-mentioned disk electrodes, there are through channels of variable cross-section perpendicular to the lateral surface of the central opening. FIG. 2 shows one of the disc electrode assembly. The filler from the group of low-melting or highly volatile chemical elements or their compounds is placed in a part of the channel of a larger cross section. At the same time, the number of channels, the length and diameter of a part of a channel of smaller cross section depend on the volatility wall of the chemical element or its compound. For example, in disk electrodes designed to study the spectra of Na, Cd, Zn, channels of smaller cross section have a diameter

0.3-1.5 and a length of 1-2 mm (depending on the element). In this case, Na is placed in channels in glass ampoules, which are then destroyed during the manufacture of the lamp in the exhaust station.

Between disc electrodes made in a similar manner, a glow discharge is ignited, which, due to the effects of a hollow cathode (cathode sputtering) and thermal evaporation, produces a definite atomic vapor bandwidth inside the holes of the disc electrodes, which is then emitted by an arc discharge passing through the positive column these electrodes.

Subject invention

Spectral high-intensity lamp according to ed. St. No. 264551, characterized in that, with

In order to increase the service life, the disk electrodes are made with end-to-end located perpendicular to the side surface channels filled with low-melting or easily volatile chemical elements.

or their compounds mi .....

s / g f

ife X