SU308672A1 - Gas Dynamic Pulsed Light Source - Google Patents

Description

The invention relates to gas-discharge light sources, in particular, to gas-dynamic impulse devices, in which the radiation emitted during the interaction of counter-directed shock waves and the gas-discharge nlazm is used.

The proposed gasdynamic pulsed light source is designed to produce multiple intense light flashes of short duration, mainly used for optical pumping of liquid active media based on organic dyes (liquid lasers), as well as during flash photo shooting of solutions.

A pulsed discharge light source is known, and a 4-tip op impact shock T: wheelhouse and made in the form of a xenon-filled T-shaped quartz bulb in which electrode nodes with a matching longitudinal axis are mounted symmetrically with respect to the tubular process of the bulb. The rapid expansion of the gas resulting from the release of Joule heat during the passage of a current pulse through the gas, as well as the electromagnetic interaction of the discharge current with the transverse magnetic field created by the return current of the discharge circuit flowing through the metal bar located on the flask along the discharge gap , contributes to the splashing of the gas-discharge plasma into a cylindrical process, generating a shock wave.

The main disadvantage of such a pnumulus light source is a low QC. e. converting the input energy into useful light radiation, used for pumping, since 40-50% of the energy, but not in the discharge, is dissipated in bulk with the help of radiation passing through the transparent walls, limiting the plasma in the discharge gap. In this case, only the radiation emitted by the expansion of gas into the process of the gas discharge plasma and shock waves is used. In turn, increasing

The rate of accumulation of energy of the gas discharge plasma of the discharge gap during a short pulse discharge increases the rate of expansion of the plasma column in the radiating cylindrical process n and contributes to obtaining stronger shock waves.

Usually, at the rate of accumulation of energy in the discharge gap,

by increasing di / dt, i.e., increasing the rate of increase of the discharge circuit current, plugging the device into a low-inductive discharge circuit, resorting to a whole range of reductions: nductive (iu dirdi W a / s for no, i, o6Hijix devices.

The purpose of the invention is to create a gas dynamic: a discharge light source based on the interaction of oppositely directed shock waves and a moving gas discharge nlazma having an increased efficiency of converting the supplied electrical energy into light radiation and making it possible to obtain shorter light caps and a uniform radiation density, the outcome from the light side of the device.

The invention, which solves the problem, is based on the well-known gas-dynamic discharge light source, which contains two discharge gas-filled discharge chambers made of heat-resistant material with axial openings that are coaxial with an optically transparent tube intended for radiation output.

In order to increase the efficiency of the light source and to obtain a more uniform radiation density along the pipe, the walls of the discharge chambers are made reflective. They are made of a light reflecting material or coated with a similar material, for example, diffusely scattering silica.

A feature of the proposed light source is also the performance of said chambers with cylindrical and flat end walls on the one hand and having a conical junction on the side of the joint with an optically transparent tube, with the angle of the solution of the said taper junction ranging from 15 to 60 °.

FIG. 1 shows the proposed gasdynamic discharge light source, front view with partial section; in fig. 2 is a section along A-A in FIG. one; in fig. 3 is a block diagram of the inclusion of the specified bit device.

The proposed gas-dynamic discharge light source 1 is made in the form of two opaque discharge chambers 2 and 3 with similar design, equipped with coaxial holes that are coupled with an optically transparent tube 4 (diameter 12 mm and length 96 mm) made of fused silica glass and intended to emit radiation. These chambers are made of heat-resistant material with reflective walls, such as beryllium oxide or fused silica glass, covered with a layer of 5 reflective silicon dioxide, sintered to zero porosity. Each chamber is a hollow cylinder (18 mm diameter) with a flat end wall 6 on one side and has a conical junction 7 on the mating side with an optically transparent tube 4. The angle of the solution of the conic junction 7 of the discharge chamber into the cylindrical tube 4 is 15 -60 °.

Two pairs of cylindrical MLCKiix legs 8 (12 mm in diameter) are mounted in the axial, in which two pairs of identical electrode nodes with the same longitudinal axis of symmetry are assembled, each of which contains an electrode 9 with a flat working surface of thoriated tungsten. The electrode is pressed into a hollow cob holder 10, equipped with an annular protrusion on which a titanium cylinder 11 is placed, forming an annular gap with a leg 8, which is filled with tin during the sealing process.

Electrode assemblies mounted in legs

flask so that the flat working surface of each electrode having a diameter close to the internal diameter of the leg section is exposed to the level of the discharge volume of the chamber in the vicinity of its end wall,

parallel spacing gaps (20 mm long). Along these discharge gaps on the outer side of the bulb, perpendicular to the axis of rotation and length of the pipe 4 connecting the chambers 2 and 3, two current-carrying wires are mounted

tires 12 and 13, made in the form of metal caps, mounted on the protruding end walls of the cylindrical part of the chamber, through which a discharge current is passed to one of the electrode nodes of each

discharge camera.

O. The described discharge light source, filled with xenon up to a pressure of 50 Torr, is included in a symmetrical low-inductance discharge circuit with a common ground (see

FIG. 3), containing two terminal batteries 14 and 15, controlled by a two-channel sequential ignition unit 16, ensuring the initiation of the discharge simultaneously in two discharge chambers. The directions of the discharge currents in both discharge gaps coincide with each other and are opposite to the directions of the currents in the above-mentioned metal shells. Moving at high speed due to

thermal expansion of the gas and the electromagnetic interaction of discharge currents with the return current of the busbars of the external circuit, the plasma discharge gas is discharged simultaneously from both chambers 2 and 3 into the pipe 4 connecting them,

generating strong counter-directed shock waves. After reflection from each other, the shock waves move already along the gas-discharge plasma plasma propagating towards the expanding pillars, heated by the energy of the currents of the discharge gaps and reflected by the shock waves reflected from the chamber ends. This stage of the discharge is characterized by filling the pipe channel and a uniform radiation density.

The proposed light source has significant advantages as compared to the known gas-dynamic discharge devices, namely: - increased efficiency to transform sublight light radiation (by about 20-30%) as a result of a decrease in the dissipation of the energy of the pushing discharge plasma (" a pushing piston) due to radiation in the discharge gaps and using shock waves reflected from the flat walls of the cameo to heat the plasma;

- reduced duration of the light flash as a result of shading of the discharge gaps relative to the irradiated object, eliminating the impact on the object of the light of the slit, i.e., the residual radiation of the last stage of discharge of the storage capacitor of the discharge circuit;

- the increased filling rate of the gas-transparent plasma of an optic-transparent tube and obtaining a more uniform density of radiation emanating from it, due to the additional photoionization of the gas ahead of the shock waves moving in the pipe towards the shock waves and glowing plasma;

- to restore the velocity of shock waves in the pipe due to the transition of the discharge chamber cross sections into the specified pipe of smaller diameter.

The advantage of the light source described is also that the change in the ratio of the diameters of the radiating tube and discharge, as well as depending on the voltage on the storage battery of low-inductance discharge circuit capacitors and the pressure of the working gas, can be changed within relatively wide limits.

spectral efficiency of radiation (spectral composition of radiation). Thus, for example, reducing the ratio of the diameter of the radiating tube to the diameter of the discharge chamber, all other things being equal, increases the velocity of the shock waves and decreases the penetration of the discharge plasma into the P1 radiation, thus increasing the radiation in the ultraviolet region of the spectrum.

Claims (3)

1. Gas dynamic pulsed light source containing two chambers made of heat-resistant material filled with working gas, in which discharge gaps are mounted, an optically transparent tube connecting these chambers, and two current-carrying tires placed outside the chambers along discharge gaps connected to the control gear. which creates a discharge simultaneously in both chambers, characterized in that, in order to increase the r. d. of the light source and obtaining a more uniform radiation density along the tube, said chambers are made with reflecting walls. 2. The source of light according to claim 1, characterized in that both cameras are made with conical fitting with an optically transparent tube. 3. Light source according to nn. 1 and 2, characterized in that the angle of the conical junction of the discharge chamber into the tube for radiation output is 15-60 °. 652