RU2574584C1 - Ultraviolet excilamp in envelope made of profiled leucosapphire - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: invention is characterised by the sealed envelope, which is assembled from separate elements having a leak-tight connection between each other, the said connection being made by hard soldering, wherein the elements of the envelope are made of monocrystalline profiled leucosapphire of a given shape.

EFFECT: increasing the size of the excilamp and the radiation power of the excilamp while reducing labour input in production and the cost of the product.

2 cl, 6 dwg

Description

Technical field

The invention relates to the field of instrumentation (lighting), and in particular to the technique of radiation at transitions of excimer or exciplex molecules in electric-discharge sources of spontaneous ultraviolet radiation, called excilamps, and can be used in various fields of science and technology, for example, in medicine, for disinfection of air and liquid media as well as for the inactivation of microorganisms, in photochemistry, in microelectronics during processing and cleaning of the surface by means of its irradiation, for the detection of diamonds, for ia photostimulated processes for communication in the ultraviolet range in car driving systems.

State of the art

A large number of varieties of excilamps are known [1]. Modern excilamps have a great variety in the geometry of the flask (shell). It is known that usually the excilamp bulb is made of quartz glass (US 6376972 B1, RU 63224 U1, RU 75503 U1, RU 2281581 C1, RU 2291516 C2, RU 2310947 C1, RU 2321919 C1, RU 2385515 C1, etc.). Quartz glass has good transmission in the ultraviolet region of the spectrum, satisfactory manufacturability in the manufacture of excilamps, and relatively cheap. It is also known that the working medium in excilamps is various inert gases (helium He, neon Ne, argon Ar, krypton Kr, xenon Xe), as well as hydrogen (deuterium) and / or their mixtures with halogens (chlorine Cl ₂ , bromine Br ₂ , iodine I ₂ ) (RU 43458 U1, RU 2151442 C1, RU 2154323 C2, RU 2200356 C2, RU 2225225 C2, etc.).

As you know, an excilamp in the ultraviolet (UV) spectral region is an electric-discharge device that provides radiation in the UV spectral region, in particular, on B-X transitions of inert gases. The principle of operation of an excilamp is based on the flow of electric current in a gas, as a result of which excimer or exciplex molecules are formed in a gas-discharge plasma through various plasma-chemical reactions. A feature of these molecules is, firstly, the presence of a stable bond of these molecules only in the excited state, and the ground state is scattered. This causes radiation in wide spectral ranges (the most intense B-X band). Secondly, the kinetics of plasma-chemical reactions is such that the formation of excimer or exciplex molecules is accompanied predominantly by non-radiative processes, while a decrease in the concentration of these molecules is provided mainly by radiation transitions to the ground state. This determines the high radiation efficiency, as well as the fact that up to ~ 80% of the radiation power of a gas-discharge plasma can be concentrated in the B-X transition band of the used excimer or exciplex molecule.

The disadvantage of excilamps in a quartz flask is the relatively short service life due to intense plasma-chemical reactions, when the resulting excimer or exciplex molecules react with quartz and spoil the composition of the gas mixture in the excilamp. In addition, the quartz excilamp bulb is fragile.

The material of the excilamp flask must be capable of transmitting ultraviolet radiation well; along with quartz glass, these materials include: uviole glass, crystals of lithium fluoride LiF, crystals of magnesium fluoride MgF ₂ , crystals of calcium fluoride CaF ₂ , crystals of barium fluoride BaF ₂ , single crystals of various borates, for example, LBO (LiB ₃ O ₅ ), LB ₄ (Li ₂ B ₄ O ₇ ), BBO (β-BaB ₂ O ₄ ), CLBO (CsLiB ₆ O ₁₀ ), leucosapphire (corundum) (Al ₂ O ₃ ), etc. From of all these materials, due to their inertness to chemical influences and strength, leucosapphire is most suitable for excilamp flasks.

The disadvantages of the known solutions in relation to excilamps are relatively small sizes, the preparation of shells by machining, which leads to a large complexity and cost of products, in addition, the shells are sealed with various metal parts, which is unacceptable for excilamps.

Known discharge excimer lamp US 8164263 B2, adopted as a prototype, containing a sealed flask of leucosapphire with a working medium consisting of inert gases or their mixture, or from halogens or their mixture, or from a mixture of inert gases with halogens in a certain ratio and a certain pressure; a metal plug soldered into a flask; two metal electrodes forming a discharge gap; a high voltage pulse voltage generator connected to both electrodes.

The disadvantages of this device are the relatively small size, and therefore the radiation power, obtaining the elements of the flask by machining, which leads to great complexity and cost of products.

Disclosure of invention

The objective of the invention is to increase the size of the excilamp, and, therefore, the possibility of increasing the radiation power of the excilamp while reducing the complexity of manufacturing and cost of the product.

This is achieved by the fact that in a known technical solution containing a sealed flask made of leucosapphire with a working medium consisting of inert gases or a mixture thereof, or halogens or a mixture thereof, or a mixture of inert gases with halogens in a certain ratio and a certain pressure; a metal plug soldered into a flask; two metal electrodes, tightly adjacent to the surface of the flask and forming a discharge gap; a high-voltage pulse voltage generator connected to both electrodes, a sealed flask is assembled from separate elements having a vacuum-tight connection made by brazing, and the flask elements are made of a single-crystal shaped leucosapphire of a given shape.

Profiled leucosapphire is used in the form of straight or conical pipes, cylinders, rods, plates. Currently, shaped leucosapphire is grown with great accuracy and in most cases does not require additional mechanical processing. The diameter of the tubes of profiled leucosapphire can reach 65 ... 70 mm, length up to 1000 mm. Elements of a flask made of profiled leucosapphire are connected by vacuum-tight soldering. To pump the excilamp and fill the working medium, a metal plug is used, soldered to the flask made of profiled leucosapphire. After pumping and filling with a working medium, the plug is sealed with cold diffusion vacuum tight welding.

Brief Description of the Drawings

The claimed solution is illustrated by the following graphic materials:

in FIG. 1 shows in cross section the first variant of the ultraviolet excilamp of a barrier discharge of a coaxial type;

in FIG. 2 shows a sectional view of a second embodiment of a capacitive-discharge ultraviolet excilamp;

in FIG. 3 shows in cross section a third embodiment of a planar-type ultraviolet excilamp;

in FIG. 4 shows in cross section a fourth variant of an ultraviolet excilamp of a barrier discharge of a coaxial type with a variable width of the discharge gap;

in FIG. 5 is a sectional view of a fifth embodiment of a capacitive discharge ultraviolet excilamp;

in FIG. 6 depicts a sealed metal ram.

The excilamp according to the first embodiment (Fig. 1) contains an external leucosapphire tube 1.1, an internal leucosapphire tube 1.2, a left leucosapphire wall 1.3, a right leucosapphire wall 1.4, a metal ram 1.5, a working medium 1.6, an external perforated metal electrode 1.7, an internal solid metal electrode 1.8, generator of high voltage pulse voltage 1.9.

The excilamp in the second embodiment (Fig. 2) contains an external leucosapphire tube 2.1, a left leucosapphire wall 2.2, a right leucosapphire wall 2.3, a metal ram 2.4, a working medium 2.5, a left outer solid metal electrode 2.6, a right outer solid metal electrode 2.7, a high-voltage pulse generator voltage 2.8.

The excilamp according to the third embodiment (Fig. 3) contains an external leucosapphire tube 3.1, a left leucosapphire wall 3.2, a right leucosapphire wall 3.3, a metal ram 3.4, a working medium 3.5, a first rear outer solid metal electrode 3.6, a second rear outer solid metal electrode 3.7, a generator high voltage pulse voltage 3.8.

The excilamp according to the fourth embodiment (Fig. 4) contains an external leucosapphire tube 4.1, an internal conical leucosapphire tube 4.2, a left leucosapphire wall 4.3, a right leucosapphire wall 4.4, a metal plug 4.5, a working medium 4.6, an external perforated metal electrode 4.7, an internal conical metal 4.8, a generator of high voltage pulse voltage 4.9.

The excilamp according to the fifth embodiment (Fig. 5) contains the first outer leucosapphire tube 5.1, the second outer leucosapphire tube 5.2, the left leucosapphire wall 5.3, the middle leucosapphire wall 5.4, the right leucosapphire wall 5.5, the metal outer plug 5.6, the working electrode 5.7, the left electrode 5.7, 5.8, the right outer solid metal electrode 5.9, the generator of high-voltage pulse voltage 5.10.

Exilamps for all options work as follows.

A sealed excilamp bulb is collected from the leucosapphire elements by soldering. A metal plug is also installed on the excilamp's leucosapphire bulb. Through the plug, air is pumped out and the excilamp is filled with a working medium. After filling the excilamp with the working medium, the plug is sealed. Two metal electrodes are mounted on the excilamp. An alternating high-voltage voltage is supplied to the metal electrodes from the generator, the excilamp lights up.

Industrial applicability

The excilamps described in the description are not exhaustive. The technology for growing leucosapphire elements makes it possible to obtain elements of various profiles on high-performance equipment with high accuracy that do not require subsequent machining. The combination of simple elements from profiled leucosapphire provides the opportunity to create new varieties of excilamps.

Used Books

1. Boychenko A.M., Lomaev M.I., Panchenko A.N., Sosnin E.A., Tarasenko V.F. Ultraviolet and vacuum-ultraviolet excilamps: physics, technology and application. - Tomsk: STT, 2011 .-- 512 s.

2. Volkova G.A., Kirillova N.N., Pavlovskaya E.N., Podmoshensky I.V., Yakovleva A.V. VUV lamps on a barrier discharge in inert gases // ZhPS. 1984.Vol. 41.V. 4.P. 681-695.

3. Lomaev M.I., Skakun B.C., Sosnin E.A., Tarasenko V.F., Schitz D.V. Sealed-off effective excilamps excited by a capacitive discharge // Letters in ZhTF. 1999.V. 25.V. 21.P. 1-6.

Claims (2)

1. Ultraviolet excilamp with excitation by a barrier or capacitive discharge, emitting at the transitions of excimer or exciplex molecules, containing a sealed flask made of leucosapphire with a working medium consisting of inert gases or their mixture, or from halogens or their mixture, or from a mixture of inert gases with halogens in a certain ratio and a certain pressure; a metal plug soldered into a flask; two metal electrodes, tightly adjacent to the surface of the flask and forming a discharge gap; a high-voltage pulse voltage generator connected to both electrodes, characterized in that the sealed flask is assembled from separate elements having a vacuum-tight connection made by brazing, and the elements of the flask are made of single-crystal shaped leucosapphire of a given shape. 2. Ultraviolet excilamp according to claim 1, characterized in that the profile of the leucosapphire elements of the flask is formed by straight and / or second-order lines.

Images