RU2242781C2 - Device for protecting x-ray film in tests for liner magnetic implosion - Google Patents

Abstract

FIELD: liner magnetic implosion explosion trials.

SUBSTANCE: device for protecting cassette containing X-ray film has explosion shutter made in form of two metal plates, wedge-shaped charge located between two metal plates and thickened in the direction of the cassette, detonation channel adjacent to thickened end of wedge-shaped charge, detonator, lock made in form of thick metal plate. Cassette containing X-ray film is placed into protecting case made of two cones fastened together. Protecting case is placed into container made of thick-walled metal pipe which has thick-walled disc. Disc is mounted onto front edge of pipe and is provided with rectangular embrasure which is covered with armoring jacket. Rare end of pipe is closed with continuous cap. Soft cushions made in form of pack of smoothly pressed gaskets are disposed among embrasure, protecting case and cap.

EFFECT: improved protection of cassette against damages.

5 cl, 3 dwg

Description

The present invention relates to the field of high energy density physics and the registration of fast processes by X-ray diffraction, and in particular to devices for protecting an X-ray film cassette from damage during explosive experiments on the study of magnetic implosion of a liner.

During magnetic implosion of the liner, the main danger of damage to the X-ray film comes from the reverse current path, which under the influence of the magnetic field forms a fan of fragments that shrapnel fly apart within the 2π angle.

A device is known [Chokin J.P., Carlotti X., Zhestin M., Kachen J., Boucher J., Vanoperinge J., Kadush O., Azra A., Muje M., Vernier G., Avdoshin V.V. , Chernyshev V.K., Ivanov V.A., Pak S.V., Skobelev A.N., Volkov G.I., Egorychev B.T. High pulse power blast generator for implosion of solid-state liners. Mega-Gaussian Mega-Amp Pulse Technology and Application // Proceedings of the Seventh International Conference on the Generation of Mega-Gaussian Magnetic Fields and Related Experiments. Sarov, August 5-10, 1996 / Ed. V.K. Chernysheva, V.D. Selemira, L.N. Plyashkevich. 1997. Volume 1, pp. 267-273) ensuring the protection of the X-ray film from damage by fragments of the reverse conductor, providing for them (fragments) guaranteed absence within the angular sector directed from the X-ray machine to the film cassette.

This device contains “windows” made in the form of rectangular holes in the return conductor both from the side of the x-ray apparatus and from the side of the cassette (Fig. 1). These windows made it possible to apply an x-ray source with a low dose when radiographing the liner, to increase the contrast of images (due to the reduced thickness of the illuminated material) and to prevent the fragments from flying away from the current lead in the direction of the x-ray film.

In the cited work, the following measures were taken to protect the film cassette from the shock wave and fragments of the explosive energy source 10, explosive current sharpener 11. The energy source itself was connected to the chamber 7 using a sufficiently long transmission line 12, between the source and the chamber were a steel plate 6, concrete blocks 8 and a mound of sand 9 (Fig. 1).

The described device is an analog of the claimed object.

The protection device of the cartridge with x-ray film works as follows.

Using a 15 MA current pulse generated by an explosive energy source (VMIE), consisting of a spiral VMG (SVMG) 10, an explosive current sharpener (BOT) 11 and transmission line 12, magnetic implosion of the liner 1 is carried out.

In order to obtain detailed information about the condition of the outer surface and the symmetry of the liner to axis during X-ray diffraction, as well as to protect the cartridge with the x-ray film from damage by fragments of the reverse current lead 4, it contains “windows” made in the form of rectangular holes on the side of the x-ray apparatus 2 and from the side of the cassette 3 in the direction of radiography. The cassette with x-ray film 3 is placed in the chamber 7 opposite the x-ray apparatus 2.

The chamber 7, the cassette with the x-ray film 3, the x-ray apparatus 2, the return conductor 4 with the liner 1 with the central measuring unit (CIB) 5, are placed behind the protection, consisting of a thick-walled metal plate 6, concrete blocks 8 and an embankment of sand 9, which are reliable protect the cartridge with x-ray film from damage by fragments from a spiral explosive magnetic generator and explosive current sharpener. In addition, the effect of the shock wave was reduced due to the distance (about 3 meters) between the cassette with the x-ray film and the spiral explosive magnetic generator with an explosive current sharpener.

This X-ray film cartridge protection device was successfully implemented during the joint VNIIEF experiment - CEA / DAM, but it turned out to be very expensive. This is its main drawback.

The lack of analogue is due to the fact that in the process of magnetic implosion of the liner, due to the presence of “windows” in the return conductor, azimuthal current asymmetry arises on the liner. To reduce the resulting azimuthal current asymmetry, a return conductor equipped with “windows” must be installed at a radius significantly exceeding the initial radius of the liner, which leads to a significant increase in the inductance of the liner load, and therefore to a several-fold increase in the stored energy of the source and its corresponding rise in price.

The objective of the present invention is to reduce the cost of the system for protecting the x-ray film during experiments on the implosion of liners.

Known device (Buyko AM, Chemyshev VK, Jvanova GG, Gorbachev YN, Kuzaev AI, Kulagin AA, Mokhov VN, Pak SV, Petrukhin AA, Sofronov VN, Yakubov VB, Anderson BG, Atchison WL, Clark DA, Faehl RJ, Lindemuth IR , Reinovsky RE, Rodriguez G., Stokes JL, Tabaka LJ Simulation of Parameters of the Stationary Facility "ATLAS" by Means of Disk EMG // Book of Abstract of 28th IEEE International Conference on Plasma and 13th IEEE International Pulsed Power Conference. Las Vegas 2001. P.237) protection of the cartridge with the X-ray film from damage during explosive experiments on the study of magnetic implosion of the liner, containing (see FIG. 2) a steel protective box 13 with an X-ray apparatus 2 located inside it, an X-ray cartridge film 3, located in the cavity of thick-walled rolled steel armor 14, a 5 mm thick membrane 15 made of high-strength aluminum, a strong cover 16. In the armor 14 from the side of the X-ray apparatus 2, a rectangular hole was made for the passage of the X-ray beam, which provided radiation to the X-ray film.

In addition, from the side of the PU containing the return conductor 4, liner 1, the central measuring unit (CIB) 5, the cassette with x-ray film 3 was covered with a membrane 15. From the outer side of the armor 14, the cassette 3 was covered with a strong cover 16, which was attached to the armor with bolts.

To protect the membrane and cassette from fragments of VMIE 10 at the late stage of its operation, after radiography, a movable cylindrical shell 17 of steel 15 mm thick was provided.

Due to the limitations in the power of the X-ray apparatus 2 and the large total thickness of the materials that had to be scanned, as well as the close proximity of the X-ray film to an explosive energy source with an explosive mass of about 100 kg, the film cassette needed to be installed very close to the reverse current path ( figure 2).

The described device is a prototype of the claimed object.

The prototype works as follows.

Using a 30 mA current pulse from VMIE, a magnetic implosion of the liner is carried out. The cassette with an x-ray film was located in the cavity of thick-walled armor 4 and was covered from the inside with a metal membrane, and from the outside - with a lid from the impact of the shock wave and damage by fragments of the reverse current lead and VMIE.

This protection device for the cassette with the x-ray film did not fully protect it from damage during the joint explosive experience of VNIIEF-LANL (ALT-1). I managed to defend myself from the effects of the VMIE fragments. However, the cassette with the x-ray film, the membrane and the armor in the cavity of which the cassette was placed turned out to be riddled with fragments of the reverse current lead.

The prototype completely eliminates the main drawback of the analogue, namely, the azimuthal current asymmetry that arises due to the presence of “windows” during the magnetic implosion of the liner, reduces the load inductance, the energy consumed from VMIE and the cost of the protection device, but does not solve the problem of protecting the cassette with x-ray film from damage from the shrapnel of the reverse conductor.

The problem to which the invention is directed, is to protect the cassette with an x-ray film from damage by fragments of the reverse current lead and VMIE without increasing the cost.

The technical result is to ensure the preservation of the cassette with x-ray film as the main source of information about the magnetic implosion of the liner while eliminating the azimuthal current asymmetry, reducing the energy consumed from VMIE and, accordingly, reducing its cost.

The technical result is achieved by the fact that between the cassette with the x-ray film and the return conductor in the wedge-shaped x-ray “shadow” from the central measuring unit located on the axis of the return conductor and the liner, an explosive shutter and stopper are installed, and the explosive shutter is made in the form of two metal plates, wedge-shaped explosive charge between them, thickened in the direction of the cartridge, the detonation channel adjacent to the thickened end, and the detonator, and the stopper is in the form of a thick metal plate (figure 3).

Placing an explosive shutter in the wedge-shaped “shadow” of the x-ray beam formed by the central measuring unit does not introduce additional shading into the film’s working area.

Metal plates during reflection of fragments form a wedge with a vertex directed towards the fragments. The fragments collide with the plates of such a wedge at a very sharp angle of ~ 6 °, so the stream of fragments easily dissipates (ricochets) from the protected corner sector, in which the cassette with the x-ray film is located.

The stopper protects the film cassette from the direct effect of the detonation of the explosive shutter explosive and serves as an additional passive protection against fragments of the reverse current lead.

Exceeding the axial length of the stopper of the embrasure length and rigidly attaching it to a thick-walled metal disk outside the embrasure avoids the stopper getting inside the container.

The cassette with an X-ray film is placed in a protective case made in the form of two conical walls fastened together along the perimeter, the strength of which is sufficient so that the resulting wall deformation does not reach the plane of the film. The walls of the protective casing are conical with an angle at the apex of 140 °. This wall design has an advantage over flat walls, as allows the necessary deflection without impact on the surface of the film.

The protective case is placed in a container made in the form of a thick-walled metal pipe with a thick-walled metal disk mounted on its front end with a rectangular embrasure closed by a bulletproof vest, and a solid metal cover on its rear end. The design of the container allows you to reliably protect the cartridge with x-ray film from all sides, except for a narrow open channel for the passage of x-rays. A thick-walled metal disk with a rectangular embrasure mounted on the front end of the container, as well as a metal cover on its rear end, sharply weaken the intensity of the shock wave acting on the protective case with a cartridge inside the container. The bulletproof vest covering the rectangular embrasure serves as protection against small fragments of the flying liner.

Between the embrasure, the protective case with the cartridge and the lid there are soft pillows made in the form of a package of easily compressible gaskets. Soft cushions serve to soften the mutual impact of the protective casing with the cassette with walls, embrasure and container lid.

List of drawings:

1. Figure 1 shows an analogue of the claimed object with additional protection measures.

2. Figure 2 shows a prototype of the claimed object.

3. Figure 3 shows the inventive object.

A device for protecting a cassette with an X-ray film from damage during explosive experiments on magnetic implosion of a liner, comprising a removable cassette with an X-ray film 3, a protective housing 18, a support ring 19 mounted around the return conductor 4 of the liner 1 with a central measuring unit 5, that between the cassette with the x-ray film and the return current lead in the wedge-shaped “shadow” of the x-ray beam formed by the central measuring unit placed along the axis of the return the current lead and the liner, an explosive shutter and a stopper 20 are installed, the explosive shutter made in the form of two metal plates 21, a wedge-shaped explosive charge 22 between them, thickened in the direction of the cartridge, a detonation channel 23 adjacent to the thickened end, and a detonator 24, and a stopper 20 in the form of a thick metal plate.

The protective housing 18 is placed in a container 25, made in the form of a thick-walled metal pipe with a thick-walled metal disk 15 with a rectangular embrasure closed by a bulletproof vest 26 on its front end, and a metal cover 16 at its rear end. Between the embrasure, the protective case with a cassette and a cover placed soft pillows 27, made in the form of a package of easily compressible pads (see figure 3).

The container is mounted on the support ring so that it can be easily discarded by the shock wave over a short distance.

The claimed device for protecting a cartridge with an x-ray film from damage during explosive experiments on magnetic implosion of a liner works as follows.

Using a 30 mA current pulse from VMIE, a magnetic implosion of the liner is carried out. An impulse of magnetic pressure on the return current path breaks it and informs the fragments of the return current conductor at a speed of 2-2.5 km / s. The direction of the hazardous (from the point of view of film damage) part of the fragments of the reverse current conductor coincides with the direction of the x-rays to the removable cassette with the x-ray film. The path for x-rays to the cassette is clear. When the detonator and detonation channel are triggered, detonation is transmitted to the wedge-shaped explosive charge of the explosive shutter, which unfolds the metal plates, reflecting the fragments flying onto the film. The shock wave from the explosion of the VVMIE explosive container with a cartridge is easily discarded for a short distance, while protecting the cartridge from fragments of the VMIE.

Using a similar device for protecting a cassette with an X-ray film from damage in an explosive experiment, in ALT-2 it was possible to protect the cassette, obtain valuable information on the magnetic implosion of the liner on an X-ray film, and halve the cost of the experiment compared to the analogue (the cost of the experiment, both analog and the claimed object amounted to $ 190k, and the energy delivered to the liner in the experiment with the claimed object was twice as much).

Claims (5)

1. A device for protecting a cassette with an X-ray film from damage during explosive experiments on magnetic implosion of a liner, comprising a cassette with an X-ray film, a protective casing, characterized in that between the cassette with an X-ray film and a return conductor in a wedge-shaped “shadow” of the x-ray beam formed by the central an explosive shutter and a stopper are installed with a measuring unit placed along the axis of the return current lead and the liner, and the explosive shutter is made in the form of two metal plates tin, a wedge-shaped explosive charge between them, thickened in the direction of the cartridge, a detonation channel adjacent to the thickened end and a detonator, and a stopper in the form of a thick metal plate. 2. The device according to claim 1, characterized in that the cassette with an x-ray film is placed in a protective housing made in the form of two cones fastened together. 3. The device according to claims 1 and 2, characterized in that the protective case is placed in a container made in the form of a thick-walled metal pipe with a thick-walled metal disk mounted on its front end with a rectangular embrasure closed by a bulletproof vest, and a metal cover on its rear end. 4. The device according to claims 1 to 3, characterized in that between the embrasure, the protective case with the cassette and the lid there are soft pillows made in the form of a package of easily compressible gaskets. 5. The device according to claims 1 to 4, characterized in that the axial length of the stopper exceeds the length of the embrasure, and the stopper is attached to a thick-walled metal disk outside the embrasure.

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