DE102022000418A1 - Arrangement for initiating an explosive, method for producing an arrangement for initiating an explosive, and method for initiating an explosive - Google Patents

Abstract

The invention relates to an arrangement (1; 61) for initiating an explosive (3), comprising the explosive, a first layer (6) arranged on the explosive and a laser beam supply device (15; 55). In this case, the laser beam supply device is set up to supply a laser beam (28, 29), in particular a laser pulse, in such a way that the laser beam (29) can act on the first layer. Furthermore, a method for producing an arrangement for initiating an explosive and a method for initiating explosives are proposed.

Description

FIELD OF THE INVENTION

The invention relates to an arrangement for initiating an explosive. Furthermore, the invention relates to a method for producing an arrangement for initiating an explosive and a method for initiating explosives.

TECHNICAL BACKGROUND

The invention and the problems on which it is based will first be explained below using the example of the initiation of a secondary explosive of a detonator, but without restricting the invention to that effect.

So-called secondary explosives are relatively insensitive to external influences compared to so-called primary explosives. From a safety point of view, therefore, a secondary explosive may be well suited for use in a detonator intended to ignite a larger main charge when triggered. However, it is comparatively more difficult to cause such a secondary explosive to react and thus to convert, and therefore to initiate. In particular, very high pressure peaks in the explosive material are required for the initiation of such secondary explosives.

Foil detonators, commonly known as “exploding foil initiators” (EFI), already exist for initiating secondary explosives. The pressure peaks required for initiating the secondary explosive are achieved here by an impact impulse of a KaptonO foil, which experiences an extremely high acceleration due to the abrupt vaporization of a metal foil and the resulting plasma.

However, the construction of such a detonator (EFI) is complex and expensive, and the function is influenced by a large number of parameters. The design, in particular the definition of the geometry and the dimensions of the bridge shape and the layer structure, of such a detonator is carried out on an experimental, empirical basis, especially since a hermeneutic, mathematical design is difficult due to the difficult processes in this system.

Changes to such a detonator are therefore associated with a great deal of effort in order to determine the effects of such changes experimentally using hardware.

Furthermore, such foil detonators require electronics for their triggering, which are designed for short-term high currents and voltages. This contributes to an increase in the volume of the component and to increased component costs.

In addition, the production of the layer structure of such foil detonators is complex and demanding.

With existing detonator concepts, it is also often necessary to arrange the ignition electronics as close as possible to the explosive in order to optimize the inductance and the resistance with regard to the ignition current.

It has already been proposed to initiate a secondary explosive by means of laser radiation generated by laser diodes. A concrete attempt at such an initiation of secondary explosives using laser diodes is described, for example, in the publication by Xiao FANG, Sheikh R. AHMAD, Laser Ignition of an Optically Sensitised Secondary Explosive by a Diode Laser, Central European Journal of Energetic Materials, 2016, 13(1 ), 103-115. Here, however, the explosive was treated with an optical sensitizer, which absorbs the laser energy and is suddenly heated.

However, the effects of such an admixture of a sensitizing additive to the actual secondary explosive on its properties are not known in every respect.

In the field of processing materials and their surfaces, there are also general methods for laser drilling and methods of so-called "laser peening".

The determination of drilling progress using piezo pressure sensors, with the help of a detection and evaluation of shock waves during laser drilling, is described, for example, in the publication "Real-time determination and control of the laser-drilled holes depth" by M. Stafe, C. Negutu, I. M. Popescu , Department of Physics, University “Polytechnica” of Bucharest, Spl. Independentei, nr. 313, Bucharest, 060042, Romania.

It would be desirable to be able to avoid the addition of a sensitizer to the actual secondary explosive to prevent any undesirable effects of the addition of such additional materials on the explosive, such as affecting the shelf life or other properties of the explosive. Changing the secondary explosive by adding an additive can also involve further work, for example in terms of documentation, testing, qualification and the like chen, require the avoidance of which would be desirable.

SUMMARY OF THE INVENTION

Against this background, the invention is based on the object of specifying an improved way of initiating an explosive, in particular a secondary explosive, with which a modification of the explosive by adding a sensitizing additive can be avoided.

According to the invention, this object is achieved by an arrangement for initiating an explosive having the features of claim 1 and/or by a manufacturing method having the features of claim 11 and/or by a method for initiating explosives having the features of claim 12.

Accordingly, an arrangement for initiating an explosive is proposed, the arrangement having the explosive, a first layer arranged on the explosive and a laser beam supply device. The laser beam supply device is set up to supply a laser beam, in particular a laser pulse, in such a way that the laser beam can act on the first layer.

• - Bereitstellen des Sprengstoffs;
• - Anordnen einer ersten Schicht auf dem Sprengstoff; und
• - Bereitstellen einer Laserstrahl-Bereitstellungseinrichtung und Einrichten dieser derart, dass mittels der Laserstrahl-Bereitstellungseinrichtung ein Laserstrahl, insbesondere Laserpuls, in der Weise bereitstellbar ist, dass der Laserstrahl auf die erste Schicht einwirken kann.

Furthermore, a method for producing an arrangement for initiating an explosive, in particular an arrangement according to the invention, is proposed, the method comprising:

• - Prepare the explosives;
• - arranging a first layer on the explosive; and
• - Providing a laser beam supply device and setting it up in such a way that a laser beam, in particular a laser pulse, can be provided by means of the laser beam supply device in such a way that the laser beam can act on the first layer.

• - Bereitstellen des Sprengstoffs, wobei auf dem Sprengstoff eine erste Schicht angeordnet ist; und
• - Aufbringen eines Laserstrahls, insbesondere Laserpulses, derart, dass der Laserstrahl auf die erste Schicht einwirkt, wodurch die erste Schicht zumindest bereichsweise erhitzt und verdampft wird und eine sich in den Sprengstoff ausbreitende Stoßwelle erzeugt wird, welche den Sprengstoff zur Detonation bringt.

Furthermore, a method for initiating explosives is provided, which comprises:

• - Providing the explosive, a first layer being arranged on the explosive; and
• - Application of a laser beam, in particular a laser pulse, in such a way that the laser beam acts on the first layer, as a result of which the first layer is heated and vaporized at least in certain areas and a shock wave that propagates into the explosive is generated and causes the explosive to detonate.

One of the findings on which the invention is based is that by applying or arranging a first layer and the action of a laser beam on this first layer, mechanical shock waves can be generated in the explosive with the help of the laser radiation, which are suitable for causing the explosive to react , without adding sensitizing substances to the explosive. This is achieved by area-wise, abrupt heating and vaporization of the first layer and the formation of a plasma stream that generates the shock waves, which then propagate into the explosive.

Any undesirable effects on the explosive can be avoided with the invention. Furthermore, considerable effort, which a change in the explosive composition can entail, can be avoided since the explosive as such can remain unchanged.

Advantageously, the explosives could be taken over as part of an existing system, which means that considerable effort, for example for qualification, can be avoided.

Furthermore, due to the use of laser radiation, the invention can be used to initiate the explosive with considerably lower electrical currents and voltages than with the conventional foil detonator, as a result of which smaller and/or more cost-effective electronic components can be used. The invention thus also makes it possible to create a “low energy detonator”, ie a detonator with a lower energy requirement for its function.

Furthermore, with the invention, in comparison with the known foil detonators, a much simpler definition and design of a detonator is possible without having to change its explosives. In particular, an analytical and hermeneutic interpretation is facilitated.

Advantageous refinements and developments of the invention result from the dependent claims and from the description with reference to the figures.

In particular, the first layer is formed from a material with a high absorptivity for the incident laser radiation.

In particular, the first layer can be formed with a material of high density. In this way, when the laser beam acts, a high pressure can be achieved from such a material due to the expansion and the resulting plasma, which is advantageous for the effective initiation of the explosive.

In one configuration, the first layer is formed with a metal, in particular a metal foil or a preferably thin metal plate. A high absorptivity and absorption rate of the first layer for the incident laser radiation can be achieved by using a metal foil or metal plate as the first layer.

In particular, the first layer, here in particular the metal foil or metal plate, can advantageously be formed with a metal of high density. In this way it is possible to effectively transmit shock waves into the explosive with the help of the first layer.

The metal foil or plate of the first layer can be made of a steel, for example. Steel is comparatively inexpensive and also has a relatively high density. However, the use of other metal materials, such as copper, is alternatively conceivable in other configurations.

In a further configuration, the first layer is formed with a laser-absorbing coating. In particular, the laser-absorbing coating can be a laser-absorbing lacquer layer. In this way, too, a high absorption rate of the laser radiation can be achieved by the first layer. A lacquer can also be applied in a simple and expedient manner.

For example, in a further development, the first layer, which is designed as a lacquer layer, can be formed with a lacquer which contains soot, for example carbon black. The use of carbon black as a pigment contributes to the fact that the incoming laser radiation is well absorbed by the lacquer layer as the first layer.

In a preferred embodiment of the invention, the arrangement also has a second layer arranged on the first layer. In this case, the second layer is formed as an insulating layer with an at least largely laser-permeable material and covers the first layer at least in regions. Furthermore, the laser beam supply device is set up here to supply the laser beam, in particular a laser pulse, in such a way that the laser beam can penetrate the second layer and act on the first layer.

In a preferred embodiment of the invention, the method for producing an arrangement for initiating an explosive further comprises arranging a second layer on the first layer, wherein the second layer is formed as an insulating layer with an at least largely laser-permeable material and is formed in such a way that it the first layer covers at least partially. Furthermore, this configuration provides for the laser beam supply device to be provided and set up in such a way that the laser beam supply device, in particular a laser pulse, can be provided by means of the laser beam supply device in such a way that the laser beam can penetrate the second layer and act on the first layer.

In a preferred embodiment of the method for initiating explosives, a second layer designed as an insulating layer with an at least largely laser-permeable material is arranged on the first layer and at least partially covers the first layer. The laser beam, in particular a laser pulse, is applied to the second layer in such a way that the laser beam penetrates the second layer and acts on the first layer for at least regional heating and evaporation and the generation of the shock wave.

A further improvement can be achieved by additionally applying or placing the second layer acting as a confinement layer on top of the first layer and impinging the laser beam on this configuration and exposing the first layer to the laser beam. The insulating layer intensifies and concentrates the shock waves in the direction of the explosive generated during the sudden heating and evaporation of the first layer and the formation of the plasma stream in some areas and prevents the shock waves from propagating in the opposite direction away from the explosive. A high shock wave amplitude and an even more effective and efficient initiation of the explosive can thus be achieved.

In one configuration, the second layer can be formed with a plastic material, for example a polyimide, such as ^Kapton® . Thus, a laser-transmissive second layer can be obtained effectively.

According to one configuration, the second layer is formed with a foil, for example a foil formed with a plastic material. Such a layer is easy to process and apply to the first layer.

In one configuration, the second layer can be formed, for example, with a film made of a polyimide, in particular a Kapton film.

In a development, the first layer is applied directly to a surface of the explosive. This can help to effectively introduce the shock waves into the explosive body.

In one configuration, the first layer can be glued onto the explosive. This achieves a simple and effective attachment of the first layer to the explosive, particularly when the first layer is formed as a metal foil or metal plate or with a metal foil or plate. Preferably, no adhesive layer is provided in an area in which the laser beam is intended to act on the first layer, in order to avoid a damping effect of the adhesive, ie this area is kept free of the adhesive layer. In other advantageous configurations, instead of gluing on the first layer, other types of attachment are also conceivable and can be used.

In one embodiment it is provided that the explosive is a secondary explosive and/or that the explosive is in the form of a hexanitrostilbene or contains a hexanitrostilbene. Hexanitrostilbene is also referred to by the abbreviation HNS.

So-called secondary explosives are much less sensitive to external influences than primary explosives. Secondary explosives can therefore be used advantageously and comparatively safely, for example in a detonator which, after ignition, can detonate a larger main charge. The invention advantageously offers the possibility of reliable detonation of such secondary explosives, which are relatively difficult to detonate, with at the same time considerable savings in effort and costs and simplification of the design.

In particular, the explosive can be designed as hexanitrostilbene IV, so-called HNS IV, or contain HNS IV.

For example, in further configurations, the secondary explosive can be manufactured as a compact or a pellet or a small plate made of HNS, in particular HNS IV.

In one embodiment, the arrangement is designed as a detonator for igniting a main charge or with such a detonator. In a detonator, the relative insensitivity of a secondary explosive can offer advantages, for example from a safety perspective.

According to one embodiment of the invention, a secondary explosive, in particular a secondary explosive of a detonator for igniting a main charge, is initiated by means of the method for initiating explosives.

According to a further embodiment, the laser beam supply device has a laser beam generation device and an optical waveguide for transmitting a laser beam generated by the laser beam generation device. The installation location of electrical and electronic components, in particular ignition electronics, including the laser beam generating device, can thus be selected independently of the installation location of the detonator and in particular of the explosive of the same. Depending on the application, the laser beam or laser pulse used for ignition can be guided via the optical waveguide, which can be flexible if required, to where the explosive with the first layer, in particular the first and second layers, is located.

In one configuration, the laser beam supply device comprises at least one laser diode, in particular a high-power laser diode. The use of a laser diode, in particular a high-power laser diode, as the laser beam generating device makes it possible to provide a high-power laser beam with a small installation space requirement.

In a further configuration, the arrangement also has a lens for focusing the laser beam. In this way, the laser radiation can be concentrated on the area of the first layer to be impinged on, which can improve the area-by-area evaporation of the first layer, the formation of the plasma and the generation of the shock waves.

In configurations of the method for initiating explosives, it is provided that the laser beam is generated by means of a laser diode, preferably a high-power laser diode, in particular in pulsed operation, and/or that the laser beam, in particular the laser pulse, is focused by means of a lens and/or that the laser beam, in particular the laser pulse, is guided to the explosive provided with the first layer, in particular the first layer and the second layer, by means of an optical waveguide.

The above configurations and developments can be combined with one another as desired, insofar as this makes sense. Further possible refinements, developments and implementations of the invention also include combinations of features of the invention described above or below with regard to the exemplary embodiments that are not explicitly mentioned. In particular, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention.

It should also be pointed out that, in particular, the configurations explained above and developments can each be applied to the arrangement for initiating an explosive, the method for producing an arrangement for initiating an explosive, and the method for initiating explosives.

character list

• 1 zeigt hierbei eine Anordnung gemäß einem ersten Ausführungsbeispiel der Erfindung in schematischer Darstellung und verdeutlicht schematisch Verfahren in Übereinstimmung mit dem ersten Ausführungsbeispiel;
• 2 zeigt hierbei eine Anordnung gemäß einem zweiten Ausführungsbeispiel der Erfindung in schematischer Darstellung und verdeutlicht schematisch Verfahren in Übereinstimmung mit dem zweiten Ausführungsbeispiel;
• 3 zeigt schematisch eine Versuchsanordnung; und
• 4 zeigt schematisch eine weitere Versuchsanordnung.

The invention is explained in more detail below with reference to the exemplary embodiments given in the schematic figures:

• 1 shows an arrangement according to a first exemplary embodiment of the invention in a schematic representation and schematically illustrates methods in accordance with the first exemplary embodiment;
• 2 shows an arrangement according to a second embodiment of the invention in a schematic representation and schematically illustrates methods in accordance with the second embodiment;
• 3 shows a schematic of a test arrangement; and
• 4 shows a schematic of another test arrangement.

The accompanying drawings are provided to provide a further understanding of embodiments of the invention. They illustrate embodiments and, together with the description, serve to explain principles and concepts of the invention. Other embodiments and many of the foregoing advantages will become apparent by reference to the drawings. The elements of the drawings are not necessarily shown to scale with respect to one another.

In the figures, the same elements, features and components that are functionally the same and have the same effect are provided with the same reference symbols unless otherwise stated.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

1 shows schematically an arrangement 1 for initiating a secondary explosive 3 according to a first embodiment. In the embodiment of 1 the explosive 3 is a hexanitrostilbene (HNS), in particular of type HNS IV. The explosive 3 is in 1 shown schematically and can be formed, for example, as a not shown in detail, pellet-shaped or platelet-shaped compact.

The assembly 1 serves as a detonator for igniting a main charge, not shown in the figures.

1 FIG. 12 further shows that a first layer 6 is arranged on an outside of the explosive 3 and a second layer 10 is arranged on the first layer 6. FIG. The first layer 6 is thus located between the explosive 3 and the second layer 10 which covers the first layer 6 . In other words, the first layer 6 forms a lower or inner layer of material, while the second layer 10 forms an upper or outer layer of material.

In this case, the first layer 6 is designed as a thin metal foil or a thin metal plate, or alternatively as a laser-absorbing coating, in particular a laser-absorbing lacquer layer. For example, in the case of the first layer 6 formed as a paint layer, the paint layer can be formed with a paint containing carbon black, e.g. In the case of a first layer 6 embodied as a metal foil or metal plate, the metal foil or metal plate can be embodied from a steel, for example.

The first layer 6, for example the metal foil/plate or lacquer layer, is preferably applied directly to the outer surface of the explosive 3. In the case of the metal foil or metal plate, this can be glued to the outer surface of the explosive 3, although in other advantageous variants and exemplary embodiments the metal foil or metal plate can be fixed to the explosive 3 in a different way.

The second layer 10, which covers the first layer 6, serves as a laser-transmissive insulating layer or damming layer, the function of which will be explained later. In this case, the second layer 10 is formed with a material which is essentially transmissive or transparent for a laser radiation used in the first exemplary embodiment, as described further below.

The second layer 10 is designed, for example, as an additional film applied to the first layer 6, wherein the film can be made, for example, from a plastic material, in particular from a polyimide such as ^Kapton® .

The arrangement 1 also includes a laser beam supply device 15 which includes a laser beam generating device 16 with one or more high-power laser diode(s) 17 and a lens 19 . Furthermore, the laser beam supply device 15 in the embodiment of FIG 1 a high-voltage assembly 36 for supplying the laser beam supply device 15, and a driver assembly 45 which is coupled to the high-voltage assembly 36 and the laser beam generation device 16.

In order to initiate the secondary explosive 3 and thus trigger its detonation, a laser pulse is generated, which impinges on the arrangement of the layers 10 and 6 as a focused laser beam 29 . The laser beam 29 penetrates the second outer layer 10, designed as an insulating layer, essentially without damaging it or being influenced by it in the form of absorption and reflection. After penetrating the second, outer layer 10, the laser beam 29 hits the first, inner layer 6, acts on it and thus suddenly heats the metal foil or plate, or the lacquer layer with which the first layer 6 is formed. The first layer 6 evaporates at least in some areas and generates a plasma flow, which in turn generates shock waves that travel through the secondary explosive 3 and detonate.

The first layer 6 is thus formed with a material which enables the first layer 6 to absorb the laser radiation with a high absorption rate.

The second layer or insulating layer 10 causes an amplification of the directional shock waves in the direction of the secondary explosive 3. In other words, the insulating layer 10 advantageously serves to prevent the shock waves from propagating in an opposite direction, away from the explosive 3, and a consequent reduction in the shock wave amplitude to prevent.

In this way, the focused laser beam 29 "drills" a kind of hole in the first layer 6, for example with an ultra-short pulse duration, which generates the shock or pressure waves, which are concentrated in the direction of the explosive 3 with the help of the second layer 10 be guided and exert pressure on the secondary explosive 3 present as an HNS pellet. By removing material from the first layer 6 , shock waves are thus generated and the pressure is exerted on the explosive 3 .

In this way, the explosive 3 does not have to be doped or sensitized with an additive as an optical sensitizer for initiation. Thus, with the arrangement 1 according to 1 in particular, possible undesired interactions of such an additive for sensitization with the explosive 3 are avoided. Instead, the initiation takes place by generating the directed, mechanical shock waves by means of the laser pulse 29 impinging on the layer structure with the layers 6, 10.

In the case of the above-described gluing of the metal foil or metal plate of the first layer 6 to the outer surface of the explosive 3, the gluing is preferably carried out in such a way that the adhesive layer is not arranged in the area of the focus of the laser beam 29. In this way, absorption of the laser beam by the adhesive layer and a loss of power associated therewith can be avoided. Undesirable thermal or mechanical influences from the adhesive are not to be expected in this case given the very rapid generation of the plasma. More preferably, the first layer 6 can instead be held on the explosive 3 without using an adhesive.

In particular when the second layer 10 is formed as a film, it can also be glued to the first layer 6, for example in an edge region thereof. Again, an area in the vicinity of the focus of the laser beam 29 is kept free of an adhesive layer. Alternatively, the second layer 10 can be held on the first layer 6 in a different way, without gluing.

The high-voltage assembly 36 of the laser beam supply device 15 in 1 contains, for example, a high-voltage source and a high-voltage ignition capacitor. The ignition capacitor is charged using the high-voltage source. Its discharge is triggered and controlled by the driver assembly 45. In principle, it is therefore conceivable in the arrangement 1 to advantageously use ignition electronics based on a principle that is already known as such, so that the outlay for designing the electronics remains limited.

In comparison with conventional foil detonators, the operation of the laser beam generating device 16 is 1 lower voltages and currents required. For example, an electrical voltage level of up to approximately 500 volts and a current of, for example, up to approximately 160 amperes in the first exemplary embodiment may be sufficient for expedient, effective operation.

In an exemplary variant for generating the laser beam 28, 29, the laser beam generating device 16 is therefore supplied with electrical energy at an electrical voltage of no more than approximately 500 volts and an electrical current of no more than approximately 160 amperes. However, other maximum voltage and current values are conceivable.

Both the lower voltage level and the lower current requirement of the laser diodes 17 in comparison, for example, with the conventional film detonators are advantageous with regard to semiconductor components such as semiconductor switches, or regarding high voltage capacitors. These components can therefore be made smaller in volume and cost, and are more readily available and readily available.

The optical power of the laser pulse 28, 29 can be, for example, between approximately 45 watts and approximately 650 watts, in particular between 125 watts and 500 watts.

• - Der Sprengstoff 3 kann unverändert bleiben;
• - es sind geringere elektrische Spannungen und Ströme erforderlich, was geringere Bauteilkosten, geringere Bauteilvolumina und eine höhere Verfügbarkeit der Bauteile ermöglicht;
• - gegebenenfalls kann eine bereits vorhandene Zünderelektronik beispielsweise in angepasster Form zum Ansteuern der Laserstrahl-Erzeugungseinrichtung 16 verwendet werden, sofern sie in der Lage ist, einen Puls mit einem geeigneten Verlauf von Strom und Spannung zu generieren - eine vollständige und aufwändige Neuentwicklung der elektronischen Anordnung kann ggf. somit vermieden werden, die Zündelektronik für die Anordnung 1 kann einen Aufbau aufweisen, der einer bereits existierenden etwa für einen Foliendetonator (EFI) vergleichbar ist;
• - es ist eine erheblich verbesserte, analytische und hermeneutische Auslegung eines Detonators möglich;
• - ein Low-energy Detonator kann, angesichts der wesentlich geringeren Spannungen und Ströme im Vergleich mit herkömmlichen Detonatoren, realisiert werden.

An arrangement 1 according to the first exemplary embodiment therefore has the following advantages in particular:

• - The explosive 3 can remain unchanged;
• - Lower electrical voltages and currents are required, which enables lower component costs, lower component volumes and higher component availability;
• - If necessary, an already existing ignition electronics can be used, for example in an adapted form, to control the laser beam generating device 16, provided that it is able to generate a pulse with a suitable course of current and voltage - a complete and complex new development of the electronic arrangement can possibly thus avoided, the ignition electronics for the arrangement 1 can have a structure which is comparable to an existing one, for example for a film detonator (EFI);
• - It is a significantly improved, analytical and hermeneutic design of a detonator possible;
• - A low-energy detonator can be realized in view of the significantly lower voltages and currents compared to conventional detonators.

Laser diodes, which are already known as such, can be used for the laser beam generating device 16 . For example, high-power laser diodes 17, for example high-power infrared laser diodes, such as are also used for LiDAR applications, can be used. However, the use of other high-power laser diodes 17 is also conceivable.

Such laser diodes are available, for example, for a centroid wavelength of λ _centroid ≈ 905 ± 10 nanometers and suitable for pulse widths between 1 nanosecond and 100 nanoseconds with an optical output power of approx. 125 W per channel and a current requirement of approx. 40 amperes. In particular, an optical output power of, for example, up to approximately 650 watts with a current requirement of approximately 60 amperes at λ _centroid ≈905±10 nanometers and pulse widths between 1 ns and 200 ns is also conceivable as an alternative.

It can be particularly acceptable for the application of the detonator if the laser diode(s) 17 used in the arrangement 1 is/are only capable of delivering the one high-power laser pulse required to initiate the explosive 3, or a few such pulses, i.e. it can be acceptable if the generation of one or a few such pulses is accompanied by damage to the diode(s) 17, especially since the diode(s) 17 is/are destroyed at the latest when the main charge detonates .

By means of the laser beam supply device 15, in 1 a high-power laser pulse is generated, which introduces a sufficient amount of energy into the explosive 3, which causes the explosive 3 to convert and thus detonate. When operating the arrangement 1 according to 1 the initiation of the explosive 3 does not take place primarily thermally, even if some heat may be introduced into the explosive 3 by the laser pulse 29 . Instead, the initiation takes place essentially mechanically by the shock wave propagating into the explosive 3 .

Here, the first layer 6, ie the metal foil or metal plate or the laser-absorbing lacquer layer, absorbs the energy of the focused laser pulse, a plasma is formed and this plasma generates a directed shock wave that runs into the explosive 3.

In an exemplary implementation of the arrangement 1 and the method for initiating the explosive 3 according to FIG 1 a pulse duration of the laser pulse of about 100 ns with an optical output power of the laser diode(s) 17 of about 125 W in total and a focus diameter of about 0.325 mm can be provided in order to introduce a sufficiently high-energy shock wave into the explosive 3. In another exemplary implementation, also with a pulse duration of 100 ns, an optical output power of the laser diode(s) 17 totaling 500 W and a focus diameter of approximately 0.65 mm can be provided. The latter case can be implemented with 4 channels of 125 W each, for example.

2 shows an arrangement 61 for initiating an explosive 3 according to a second embodiment. The second embodiment differs from the first embodiment described above only in that a laser beam supply device 55 instead of the laser beam supply device 15 of FIG 1 is provided. The laser beam supply device 55 is essentially the same Way as the laser beam supply device 15 formed, with the exception that the laser beam supply device 55 also has an optical waveguide 18. The high-energy laser pulse generated by the laser beam generating device 16 can be guided by means of the optical waveguide 18 to where the secondary explosive 3 with the layers 6 and 10 located thereon is located. In this way, the high-voltage assembly 36, the driver assembly 45, and the laser diode(s) 17 and possibly other components can advantageously be arranged away from the explosive 3, for example the HNS IV compact. At the exit of the optical fiber 18 is in 2 the lens 19, which focuses the exiting laser pulse 29 onto the layer arrangement with the first and second layers 6, 10.

A high degree of flexibility in the spatial arrangement of the detonator components is thus achieved in the second exemplary embodiment. Due to the initiation by means of a laser, the installation location of the ignition electronics is decoupled from that of the secondary explosive 3 since the laser energy can be transmitted by means of the optical waveguide 18 with almost no loss.

Going beyond what has been described above, the arrangement 61 according to the second exemplary embodiment is designed in the same way as the arrangement 1 according to the first exemplary embodiment.

The 1 and 2 further illustrate exemplary embodiments of methods for producing an arrangement 1 or 61 for initiating an explosive 3, in which in each case the first layer 6 is arranged on the secondary explosive 3, the second layer 10 is arranged on the first layer 6 in such a way that the the second layer 10 as an insulating layer covers the first layer 6 at least in regions, and the laser beam supply device 15 or 55 is provided and configured as described above.

In addition, the illustrate 1 and 2 Embodiments of methods for initiating secondary explosive 3, wherein the laser beam 29 is applied as a laser pulse to the second layer 10 or strikes it in such a way that the laser beam 29 penetrates the second, outer layer 10 essentially unhindered and without damaging it, and acting on the first, inner layer 6. As a result, the first layer 6 is heated and vaporized at least in regions, and a shock wave that migrates into the explosive 3 is generated and causes the explosive 3 to detonate.

As described above, the arrangements 1, 61 can be mathematically designed in an improved manner. For example, for experimental verification, a comparison can also be made between a foil detonator (EFI) of conventional design and an arrangement 1, 61 according to the exemplary embodiments described above.

For this purpose, a steel plate or foil with a thickness, for example in the micrometer range, can be bombarded with the laser pulse 29 on the one hand and with the flyer of an EFI on the other. Pressure waves then propagate through the steel plate/foil, and the pressure curves can be recorded using a piezo signal generator. The pressure peak amplitudes can provide a direct comparison of the two technologies. In addition, the effects of varying the focus diameter and steel plate thickness can be understood. Advantageously, the use of an explosive can be avoided in such tests, which means that costs and effort can be reduced, but the pressure peak amplitude achieved can nevertheless be compared with the amplitude of the shock waves 91 required for initiation. Experimental setups are shown schematically for the case of arrangement 1 or 61 in 3 as well as for the case of the EFI in 4 outlined, with the steel plate/foil 66, an insulating layer 67 arranged on the steel plate/foil analogous to the second layer 10, a piezo signal generator 68 and an oscilloscope 70 being shown schematically. Reference number 78 denotes a schematic EFI, reference number 91 schematically sketched pressure waves.

Although an insulating layer 10 is provided in each of the exemplary embodiments described above, which advantageously and usefully concentrates the shock waves in the direction of the explosive 3 for reliable initiation of the explosive 3, the insulating layer 10 can be omitted in other, likewise advantageous and useful exemplary embodiments a sufficiently high-energy laser beam 29, in particular a laser pulse, acts directly on the material layer 6 and initiates the explosive 3. For a corresponding attempt, you can optionally in 3 the insulating layer 67 can be omitted.

Although the invention has been fully described above on the basis of preferred exemplary embodiments, it is not limited to them, but can be modified in many different ways.

Reference List

1

arrangement

3

explosive

6

first layer

10

second layer

15

Laser beam deployment device

16

Laser beam generating device

17

laser diode

18

optical fiber

19

lens

28

laser beam

29

focused laser beam

36

high voltage assembly

45

driver assembly

55

Laser beam deployment device

61

arrangement

66

steel plate

67

insulation layer

68

Piezo signal generator

70

oscilloscope

78

EFI

91

pressure waves

Claims (16)

Arrangement (1; 61) for initiating an explosive (3), having the explosive (3), a first layer (6) arranged on the explosive (3), and a laser beam supply device (15; 55) which is set up to supply a laser beam (28, 29), in particular a laser pulse, in such a way that the laser beam (29) can act on the first layer (6). arrangement according to claim 1 , characterized in that the first layer (6) is formed with a metal, in particular a metal foil or metal plate, or that the first layer (6) is formed with a laser-absorbing coating, in particular a laser-absorbing lacquer layer. arrangement according to claim 1 or 2 , characterized in that the arrangement (1; 61) has a second layer (10) arranged on the first layer (6), the second layer (10) being formed as an insulating layer with an at least largely laser-permeable material and the first layer (6) covers at least some areas, and that the laser beam supply device (15; 55) is set up to supply the laser beam (28, 29), in particular a laser pulse, in such a way that the laser beam (29) covers the second layer (10) can penetrate and act on the first layer (6). arrangement according to claim 3 , characterized in that the second layer (10) is formed with a film, for example a film formed with a plastic material. Arrangement according to at least one of the preceding claims, characterized in that the first layer (6) is applied directly to a surface of the explosive (3). Arrangement according to at least one of the preceding claims, characterized in that the explosive (3) is a secondary explosive and/or that the explosive (3) is designed as a hexanitrostilbene or contains a hexanitrostilbene. Arrangement according to at least one of the preceding claims, characterized in that the arrangement (1) is designed as one or with a detonator for igniting a main charge. Arrangement according to at least one of the preceding claims, characterized in that the laser beam supply device (55) has a laser beam generating device (16) and an optical waveguide (18) for transmitting a laser beam (28) generated by the laser beam generating device (16). Arrangement according to at least one of the preceding claims, characterized in that the laser beam supply device (15; 55) comprises at least one laser diode (17), in particular a high-power laser diode. Arrangement according to at least one of the preceding claims, characterized in that the arrangement (1; 61) also has a lens (19) for focusing the laser beam (28). Method for producing an arrangement (1; 61) for initiating an explosive (3), in particular an arrangement (1; 61) according to one of the preceding claims, comprising: providing the explosive (3); arranging a first layer (6) on the explosive (3); and Providing a laser beam supply device (15; 55) and setting it up in such a way that the laser beam supply device (15; 55) can be used to supply a laser beam (28, 29), in particular a laser pulse, in such a way that the laser beam (29) the first layer (6) can act. A method for initiating explosives (3), comprising: providing the explosives (3), a first layer (6) being arranged on the explosives (3); and application of a laser beam (28, 29), in particular a laser pulse, in such a way that the laser beam (29) acts on the first layer (6), as a result of which the first layer (6) is heated and vaporized at least in certain areas and a layer that is embedded in the explosive ( 3) propagating shock wave is generated, which detonates the explosive (3). procedure after claim 12 , characterized in that arranged on the first layer (6) is a second layer (10), which is designed as an insulating layer with an at least largely laser-permeable material and covers the first layer (6) at least in regions, and in that the laser beam (28, 29 ), in particular a laser pulse, is applied to the second layer (10) in such a way that the laser beam (29) penetrates the second layer (10) and acts on the first layer (6) for at least regional heating and evaporation and the generation of the shock wave . procedure after claim 12 or 13 , characterized in that the first layer (6) is formed with a metal, in particular a metal foil or metal plate, or with a laser-absorbing coating, in particular a laser-absorbing lacquer layer, and/or that the second layer (10) is formed with a film, for example a with a plastic material formed foil. Procedure according to one of Claims 12 until 14 , characterized in that a secondary explosive (3), in particular a secondary explosive of a detonator for igniting a main charge, is initiated by means of the method. Procedure according to one of Claims 12 until 15 , characterized in that the laser beam (28, 29) is generated by means of a laser diode (17), preferably a high-power laser diode, in particular in pulsed operation, and/or that the laser beam (28), in particular laser pulse, is generated by means of a lens (19) is focused and/or that the laser beam (28), in particular a laser pulse, is applied by means of an optical waveguide (18) to the explosive (3 ) is introduced.

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