SU1608438A1 - Spectral gas-discharge lamp for atomic absorption - Google Patents

Abstract

The invention relates to spectral light sources intended for operation in atomic absorption analysis equipment. The aim of the invention is to reduce the time to enter the mode. The spectral gas discharge lamp contains a glass balloon 1, a flat window 2, an anode 3, a cathode 4. A sleeve is installed coaxially with it in the hole of the hollow cathode. The sleeve has two annular protrusions. The mathematical dependence of the thickness of the wall of the sleeve and the size of the gap formed between the outer surface of the sleeve and the inner surface of the cathode on the diameter of the discharge cavity of the sleeve is given. 2 ill., 1 tab.

Description

The invention relates to the class of spectral light sources intended for operation in atomic absorption analysis equipment.

The purpose of the invention is to reduce the time of entry into the stable lamp operation mode.

FIG. 1 shows the spectral discharge of the lamp, general view; in fig. 2 to a node with a sleeve installed inside the cavity of the cathode.

The lamp is a glass cylindrical n- and cylinder 1 with a window 2 for radiation output, an anode 3 made of nickel, a cylindrical form and a hollow cathode 4, in opening 5 of which a sleeve 6 is installed. The outer side surface of the sleeve 7 has two the protrusion 8 and 9. The diameter of the protrusion 8 is equal to the diameter of the cavity of the cathode 10, and the diameter of the protrusion 9 is equal to the diameter of the outer surface of the cathode 11. With these projections, the sleeve is installed in the center of the cathode opening and is fixed on its end by spot welding. A gap 12 is formed between the protrusions 8 and 9, the inner surface of the cathode 10 and the outer surface of the sleeve 7. The hollow cathode is installed in the electrically insulating tube 13. The cathode, anode and electrically insulating tube are mounted on the glass stem 14 using molybdenum leads 15, which are soldered flexible wires 16 terminated by standard single-pole plug tips 17. Solder joints and molybdenum leads coming out of the lamp are placed in PVC vinyl insulating tubes 18. The anode outlet inside the lamp for sol tion of the gas discharge is placed in the glass tube 19. The lamp is filled with an inert gas to the required pressure via the process 20, 1: 1ilindrichesky anode is connected to the anode input via nickel contact 21. By connecting this

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A lamp to the power supply between the internal cavity of the sleeve 6 and the cylindrical anode 3 ignites a glow discharge in an inert gas. Under the action of ion bombardment and thermal evaporation, the cathode sleeve material is sprayed. Sputtered products in the form of neutral atoms fall into the gas discharge and are excited.

Example. The lamp is a cylindrical glass cylinder {5 40 mm with a flat window for radiation output, transparent in the ultraviolet part of the spectrum, a cylindrical anode i 10.0 mm and 10 mm long made of nickel of grade NP 2, 0.2 mm thick and a hollow cathode with a diameter of 9.8 mm with a blind hole f5 9jD mm and a length of 14 mm. Inside the cathode opening there is a sleeve, made of vacuum-melted iron. The thickness C1; the sleeve sleeve is 0.4 mm and the gap formed between the inner surface of the cathode and the outer surface of the sleeve is 2.0 mm. The bore diameter of the sleeve is 4.0 mm and a length of 10 mm. The hollow cathode is installed in a glass tube, which outside the discharge cavity of the cathode has a diameter of 15 mm and a length of 15 mm. The hollow cathode, the anode and the glass tube are assembled on the glass stem with the help of molybdenum 1.5 mm leads, to which flexible wires are soldered to the outside of the lamp, terminating in standard plugs of type L4. The lamp is filled with neon inert gas up to a pressure of 9.0 mm Hg.

The measurement of the time of entry into the stable operation mode and the instability of the radiation of the iron 248.3 nm resonance line in time is carried out on a Spectrum-5 type analyzer. For comparison, a known lamp is used, selected as a prototype. During the entry into stable operation mode, a gap is assumed.

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Scientific research institute

1ce which instability of the intensity of the radiation of a resonant

varies within the limits specified in the lamp specifications. The entry mode or progression lamp is measured by examining the change in the intensity of the radiation of the resonance line of iron in te. (; 60 minutes of continuous operation after turning on the lamp; In pulsed mode. Drip (pulse frequency 1100 μs with a repetition rate of 40 Hz, the Signal

It is streamed on the recording recorder potentiometer of the RU-12 recorder on the scale.

The measurement results are shown in the table at the same voltage on the photomultiplier and the slits of the monochromator.

Thus, the time of entry into a stable mode of operation is reduced by 3 times, the instability of the intensity of the radiation of the resonance lines (drift) for 30 minutes is 1.6 times.

The data given in the table practically confirm the theoretical TERMINALS for reducing the time of entry into a stable mode of operation.

Fo) Mula Invention

A spectral gas discharge lamp for 1-volume absorption, containing a flask with a window at the end for outputting radiation, inside which a hollow cathode is placed in the electrically insulating tube, as well as an anode, characterized in that, in order to reduce the time to enter the mode, it is equipped with a sleeve cylindrical shape made of the material under study

la with wall thickness D1 (0.05 ... ... 0.15) d (where d is the diameter of the sleeve plane, the sleeve is installed on the three cathodes coaxially with it, and on the edges of its outer surface are

annular protrusions, with the diameter of the annular protrusion on the part of the sleeve facing the bottom of the cathode equal to the inner diameter of the cathode, and the diameter of the annular protrusion on the opposite

the part of the sleeve adjacent and attached to the end of the cathode is equal to the external diameter of the cathode, while the sleeve and the cathode are installed with a clearance of D S relative to each other equal to & S,

 (0.2 ... 0.6) d ,.

FIG. Z

Claims (1)

Formula FROM: for flasks, isolated, wife: made of the studied material · 25 la with a wall thickness D1 = (0.05 ... .0.15) (1 /, where d, is the diameter of the plane of the sleeve, the sleeve is installed inside the cathode coaxially with it, and at the edges of its outer surface are made 30 annular protrusions, the diameter of the annular protrusion on the part of the sleeve facing the bottom of the cathode is equal to the inner diameter of the cathode, and the diameter of the annular protrusion on the opposite 35 parts of the sleeve adjacent and attached to the end of the cathode is equal to the outer diameter of the cathode, while the sleeve and cathode are installed with a gap Д S relative to each other, equal to 4S = ₄₀ = (0.2 ... 0.6) d <.