Local energy concentration

Abstract

A system for generating a localized concentration of energy from an input shockwave 12 comprises an amplifier 2 arranged to manipulate one or more of a velocity, pressure or shape of the input shockwave, the amplifier 2 comprising a body composed of a first material defining a cavity for manipulating the input shockwave to generate a manipulated shockwave. The cavity comprises an input end used for receiving input shock waves incident on the amplifier and an output end used for outputting manipulation shock waves, and the cross section area of the output end is smaller than that of the input end. The system further comprises a target 4 configured to contain a fuel 8. The amplifier 2 and the target 4 are configured such that the manipulating shockwaves are arranged to be output from the amplifier 2 so as to be incident on the target 4.

Description

[0001] The present invention relates to a method and apparatus for producing high local energy concentration.

[0002] It has been shown in WO 2011 / 138622 that the interaction between the shock wave in the non-gaseous medium and the gaseous medium can generate a high-speed lateral jet of the non-gaseous medium moving through the gaseous medium. This causes the jet to hit and capture a certain volume of the gaseous medium (e.g., hit a target), thus generating a strong energy concentration in the gas.

[0003] The present invention seeks to provide an alternative technique for producing localized energy concentration.

[0004] Viewed from a first aspect, the present invention provides a system for generating local energy concentration, the system comprising:

[0005] An amplifier arranged to manipulate one or more of the velocity, pressure or shape of an input shock wave, wherein the amplifier comprises:

[0006] a body comprising a first material;

[0007] wherein the body defines a cavity for manipulating the input shock wave to produce a manipulated shock wave;

[0008] The cavity includes:

[0009] an input terminal for receiving the input shock wave incident on the amplifier; and

[0010] an output terminal for outputting a manipulated shock wave,

[0011] wherein the system further comprises a target configured to contain the fuel; and

[0012] Therein, the amplifier and the target are configured such that the manipulated shock wave is arranged to be output from the amplifier so as to be incident on the target.

[0013] Thus, the present invention provides a system comprising: an amplifier that manipulates the shock wave when the shock wave is incident on the amplifier; and a target that contains fuel so that the fuel is impacted by the manipulated shock wave output from the amplifier. The amplifier has an input end (e.g., an orifice) for receiving the input shock wave and an output end (e.g., an orifice) for outputting the manipulated shock wave. The cavity is designed (e.g., shaped) to manipulate the shock wave when the shock wave passes through the cavity.

[0014] Thus, it can be seen that by providing a system having an amplifier configured to manipulate an input shock wave (the amplifier being disposed separately from the target), the shock wave can be manipulated to provide a higher pressure at the target. Further, the modular (e.g., separate amplifier and target) nature of the system allows different target designs to be used with different amplifier designs. This increases the configurability of the system, which may be particularly useful during experimentation.

[0015] The body of the amplifier made of the first material defines a cavity within the body. Thus, the cavity (eg, a volume defined by and within the body) is preferably surrounded by the body (eg, except for the input and output terminals).

[0016] In an embodiment, the cavity contains a second material having a lower impulse impedance than the first material. Preferably, the second material is located between the input and output ends of the cavity. Thus, the body preferably comprises a material having an impulse impedance higher than the (second) material of the cavity (e.g. at least some of the cavity) or the (second) material contained therein.

[0017] In an embodiment, the amplifier (and thus the cavity) is shaped such that the cross-sectional area of ​​the input end is larger than the (e.g. corresponding) cross-sectional area of ​​the output end. The cross-sectional area of ​​the input end and / or the output end may be defined in a plane substantially perpendicular to the direction between the input end and the output end, e.g. such that the cross-sectional area of ​​the input end is substantially parallel to the cross-sectional area of ​​the output end, e.g. the input orifice (the plane of the input orifice) is substantially parallel to the output orifice (the plane of the output orifice). The direction between the input end and the output end may be substantially parallel to the direction along which the input shock wave is arranged to propagate to be incident on the amplifier in embodiments of the invention.

[0018] In an embodiment, the amplifier (and therefore the cavity) may be shaped such that the cross-sectional area of ​​the cavity in a plane substantially perpendicular to the direction between the input and output ends may decrease linearly or non-linearly. In an embodiment, the cross-sectional area of ​​the cavity may initially increase and then decrease when moving from the input end toward the output end. In an embodiment, the cross-sectional area of ​​the output end may be larger than the cross-sectional area of ​​the input end (e.g., the cavity may have a flared output end). Thus, for example, the cross-sectional area of ​​the cavity may initially decrease and then increase when moving from the input end toward the output end.

[0019] In an embodiment, the minimum distance between the input end and the output end (e.g., the minimum distance between two points on the input end and the output end (their respective orifices)) is greater than the maximum dimension of the output end (e.g., the maximum distance from one point on the periphery to another point on the periphery, e.g., a diameter).

[0020] In an embodiment, the minimum distance between the input end and the output end (e.g., the minimum distance between two points on the input end and the output end (their respective orifices)) is greater than the maximum dimension of the input end (e.g., the maximum distance from one point on the periphery to another point on the periphery, e.g., a diameter).

[0021] The body can have any suitable and desired dimensions, such as will be determined by the specific application of the amplifier. In one embodiment, the thickness, diameter and / or maximum dimension of the body (e.g., the cavity of the body) is between 0.1 mm and 100 mm, such as between 1 mm and 50 mm, such as between 2 mm and 10 mm, such as about 3 mm, 5 mm or 8 mm.

[0022] In an embodiment, the body is formed of (comprising, e.g. consisting of) a first material, and the cavity contains (e.g., is at least partially filled with) a second material. In such an embodiment, the impact impedance of the second material is lower than the impact impedance of the first material. Thus, the cavity (the shape of the cavity) is defined by the body (e.g., the inner wall of the body) (formed by the first material), and the second material is located within the volume of the cavity.

[0023] Thus, in embodiments, due to the difference in the impact impedance of the cavity (e.g., the shape of the cavity) and the first material and the second material, the amplifier can be used to manipulate the input shock wave (e.g., modify its shape and / or strength). Thus, the (e.g., energy) intensity of the shock wave transmitted from the output end of the cavity can be greater than the (e.g., energy) intensity of the input shock wave received at the input end of the cavity.

[0024] The body may comprise any suitable and desired shape (e.g., (inner) walls having such a shape) to define the cavity. Preferably, a dimension (e.g., a lateral dimension, in a direction substantially perpendicular to the direction between the input end and the output end) of the body is (e.g., substantially, e.g., significantly) larger than a (e.g., lateral) dimension of the cavity. Thus, preferably, the walls of the body are thicker than one or more (e.g., all) of the dimensions of the cavity (e.g., its width (e.g., diameter) at its input end, e.g., its width (e.g., diameter) at its output end, e.g., its largest dimension). This helps to control the boundary conditions of the shock wave as it passes through the cavity.

[0025] In an embodiment, the cavity (e.g. a segment of the cavity) comprises a frustum, e.g. the body is shaped to define a frustum-shaped cavity. Thus, preferably, a cross-section of the cavity (e.g. in a plane parallel to the direction between the input and output ends) comprises straight sides (walls), and, e.g., the cross-section is symmetrical (in this plane).

[0026] The frustum may comprise any suitable and desired type of frustum. In an embodiment, the cavity comprises a conical frustum. Thus, preferably, the cavity is rotationally symmetric about an axis passing through the cavity. Preferably, the axis of the body or cavity is parallel to the direction between the input end and the output end.

[0027] In embodiments, a cavity (a cross-section and / or a wall of the cavity) comprises two or more segments that make different respective angles with an axis of the cavity (e.g., an axis of rotational symmetry of the cavity, e.g., parallel to a direction between an input end and an output end). Thus, for example, a cavity may comprise two or more frustums (e.g., for each pair of successive frustums, an output end of one frustum coincides with an input end of another frustum), wherein the two or more frustums have sidewalls that make different respective angles with the axis of the cavity. Providing different angles by segments of the cavity may help manipulate the input shock wave in a particular manner, e.g., to accelerate the input shock wave from the input end to the output end.

[0028] In embodiments where the cavity has three or more frustum segments, each segment may be at a different angle to each of the other segments; however, two or more of the segments may be at the same angle, with one or more intermediate segments of the cavity being at a different angle.

[0029] In embodiments, instead of or in addition to the cavity having one or more straight-sided segments (in cross-section), the cross-section of the cavity may have segments with one or more curved walls. For example, the cavity may include a trumpet-shaped (e.g., conical) frustum in which the cavity walls (e.g., elliptical) are curved. These types of shapes may help make the impact front and impact shape more uniform at the output end.

[0030] In an embodiment, the amplifier comprises one or more impedance matching layers. The impedance matching layers help to couple energy between different material layers. The impedance matching layers may comprise a (middle) material layer disposed between two other materials, wherein the impedance matching layer is formed of a material having an impulse impedance between the impulse impedances of the two materials.

[0031] For example, a copper layer may be disposed between an aluminum layer and a tantalum layer.In an embodiment, the impedance matching layer may include multiple materials arranged in (eg parallel) layers such that the impulse impedance changes (eg stepwise) between the layers.

[0032] In an embodiment, the amplifier includes an input impedance matching layer adjacent to (e.g., extending across) an input end of the cavity (e.g., an aperture of the input end). The input impedance matching layer helps improve the transmission of energy (e.g., from an incident projectile) into the second material by helping to reduce reflection elements of the input shock wave (e.g., reflections from a surface of the second material). Thus, the input impedance matching layer can help couple the input shock wave into the cavity.

[0033] In an embodiment, the input impedance matching layer comprises a planar layer. The input impedance matching layer may comprise (e.g., consist of) a material having an impact impedance greater than that of the second material, e.g., less than that of the first material, e.g., an impact impedance between that of the first material and that of the second material.

[0034] In an embodiment, the impact impedance of the input impedance matching layer is between the impact impedance of (the material of) the impact projectile configured to generate an input shock wave (eg, when impacting an amplifier) ​​and the material of the second material.

[0035] In an embodiment, the amplifier includes an output impedance matching layer adjacent to (e.g., extending across) an output end of the cavity (e.g., an aperture of the output end). The output impedance matching layer helps improve the transmission of energy from the cavity (e.g., the second material of the cavity) by helping to reduce the reflection element of the shock wave (e.g., reflection from the output surface of the second material) as the shock wave is output from the cavity. Thus, the output impedance matching layer can help couple the shock wave out of the cavity.

[0036] In an embodiment, the output impedance matching layer comprises a planar layer. The output impedance matching layer may comprise (e.g., consist of) a material having an impact impedance less than an impact impedance of the second material, e.g., an impact impedance greater than a material (e.g., fuel or target) on which the output shock wave will be incident, e.g., an impact impedance intermediate between an impact impedance of the second material and an impact impedance of a material (e.g., fuel or target) on which the output shock wave will be incident. In an embodiment, the output impedance layer comprises polymethylpentene, e.g., TPX (RTM).

[0037] In an embodiment, the cavity is partially filled with the second material, i.e., the second material does not (completely) fill the cavity. Thus, in an embodiment, the cavity comprises a gap between the input end of the cavity and (the input surface of) the second material. Depending on the size and / or shape of the incident projectile that may be used to generate the input shock wave, providing a gap between the input end (e.g., orifice) and the second material in the cavity may allow the projectile to directly impact the body of the amplifier (e.g., a wall of the cavity of the body), e.g., and then impact the second material. This may generate a lateral shock wave within the projectile, which may then be transmitted into the cavity.

[0038] The lateral shock waves within the projectile can help to provide lateral focusing within the projectile. This in turn has the effect that the shock waves transmitted into the cavity are more focused towards the central axis of the cavity.

[0039] This is itself considered to be novel and inventive and therefore, viewed from another aspect, the invention provides a system for producing localized energy concentration, the system comprising:

[0040] An amplifier for manipulating an input shock wave, wherein the amplifier comprises:

[0041] a body comprising a first material;

[0042] wherein the body defines a cavity for manipulating the input shock wave to produce a manipulated shock wave;

[0043] The cavity includes:

[0044] an input for receiving the input shock wave incident on the amplifier; and an output for outputting the manipulated shock wave from the cavity;

[0045] wherein the cavity contains a second material, the impact impedance of the second material being lower than the impact impedance of the first material; and

[0046] wherein the cavity includes a space between an input end of the cavity and an input surface of the second material;

[0047] wherein the system further comprises a target configured to contain the fuel; and

[0048] Therein, the amplifier and the target are configured such that the manipulated shock wave is arranged to be output from the amplifier so as to be incident on the target.

[0049] It will be appreciated that this aspect may (and preferably does) include one or more (eg all) of the preferred and optional features disclosed herein, for example, where applicable, in relation to other aspects and embodiments of the invention.

[0050] The space between the input end of the cavity and (the input surface of) the second material can be filled with any suitable and desired material. In one embodiment, the space comprises a vacuum. In one embodiment, the space is filled with a gas. The gas may comprise any suitable and desired gas.

[0051] In an embodiment, the cavity houses a plurality of (e.g. parallel) layers, wherein one or more of the plurality of layers comprises (e.g. consists of) the second material. Preferably, the layers are parallel to an input end and / or an output end (e.g. an orifice) of the cavity, e.g. perpendicular to a direction between the input end and the output end. Thus, the layers are preferably perpendicular to a direction along which the input shock wave is arranged to propagate to be incident on the amplifier.

[0052] Providing multiple layers helps to superimpose the components of the input shock wave reflected from the boundaries between the layers. This helps to amplify the intensity of the shock wave between the input and output ends of the cavity.

[0053] This is itself considered to be novel and inventive and therefore, viewed from another aspect, the invention provides a system for producing localized energy concentration, the system comprising:

[0054] An amplifier for manipulating an input shock wave, wherein the amplifier comprises:

[0055] a body comprising a first material;

[0056] wherein the body defines a cavity for manipulating the input shock wave to produce a manipulated shock wave;

[0057] The cavity includes:

[0058] an input terminal for receiving the input shock wave incident on the amplifier;

[0059] an output end for outputting the manipulated shock wave from the cavity; and a plurality of (e.g., parallel) layers between the input end and the output end;

[0060] wherein one or more of the plurality of layers comprises a second material, the impact impedance of the second material being lower than the impact impedance of the first material;

[0061] wherein the system further comprises a target configured to contain the fuel; and

[0062] Therein, the amplifier and the target are configured such that the manipulated shock wave is arranged to be output from the amplifier so as to be incident on the target.

[0063] It will be appreciated that this aspect may (and preferably does) include one or more (e.g. all) of the preferred and optional features disclosed herein, e.g., where applicable, in connection with other aspects and embodiments of the invention. Thus, for example, preferably, the layers are parallel to the input and / or output (e.g., orifice) of the cavity, e.g., perpendicular to the direction between the input and output. Preferably, the shape of the body is arranged such that the cross-sectional area of ​​the input is larger than the cross-sectional area of ​​the output.

[0064] In an embodiment, the plurality of layers comprises at least one first layer and at least one second layer, wherein the at least one first layer comprises (e.g., consists of) a third material, and the at least one second layer comprises (e.g., consists of) the second material. In an embodiment, the impact impedance of the third material is higher than the impact impedance of the second material.

[0065] In embodiments, the third material is the first material (the same material as the first material). Thus, in these embodiments, the plurality of layers includes at least one first layer and at least one second layer, wherein the at least one first layer includes (e.g., consists of) the first material and the at least one second layer includes (e.g., consists of) the second material.

[0066] In an embodiment, the second material may be a solid, a liquid or a gas. In an embodiment, one or more second layers may be a vacuum.

[0067] In an embodiment, the plurality of layers comprises a plurality of first layers and / or a plurality of second layers, wherein the plurality of layers alternate between the first layers and the second layers, for example, a first layer (each of one or more of them) is adjacent to two second layers (sandwiched between the two second layers) and / or a second layer (each of one or more of them) is adjacent to two first layers (sandwiched between the two first layers).

[0068] In embodiments where the plurality of layers includes a plurality of first layers and / or a plurality of second layers, each of the first layers may include (e.g., consist of) the same (e.g., third) material and / or each of the second layers may include (e.g., consist of) the same (e.g., second) material. However, in some embodiments, one or more of the plurality of first layers may include (e.g., consist of) a material different from the third material, and / or one or more of the plurality of second layers may include (e.g., consist of) a material different from the second material.

[0069] In an embodiment, one or more of the first layer and / or the second layer comprises a composite layer, such that the layers include (e.g., are composed of) sublayers. The sublayers may be formed of different materials (e.g., different materials from other sublayers and / or different materials from the second material and the third material).

[0070] The multiple layers may have any suitable and desired thickness (the dimension of the planes extending perpendicular to and parallel to the layers). For example, each of the multiple layers has the same thickness. In an embodiment, the multiple layers (e.g., each) have different thicknesses. In an embodiment where the multiple layers include at least one first layer and at least one second layer, preferably one or more (e.g., all) (e.g., each) of the at least one second layer has a thickness greater than one or more (e.g., all) (e.g., each) of the at least one first layer.

[0071] In embodiments where the plurality of layers comprises a plurality of first layers and / or a plurality of second layers, each of the plurality of first layers may have the same thickness and / or each of the plurality of second layers may have the same thickness, preferably wherein the thickness of the plurality of second layers (e.g. each) is greater than the thickness of the plurality of first layers (e.g. each). In embodiments, the thickness of the plurality of first layers varies between the first layers. In embodiments, the thickness of the plurality of second layers varies between the second layers. In embodiments, the thickness of the plurality of first layers decreases (e.g. gradually) from the input end to the output end. In embodiments, the thickness of the plurality of second layers decreases (e.g. gradually) from the input end to the output end.

[0072] In an embodiment, the second material may extend across (eg fill) (the width of) the cavity, ie in a direction perpendicular to the direction from the input to the output.

[0073] In an embodiment, when the cavity accommodates multiple layers, one or more (e.g., all) of these layers extend across (the width of) the cavity (i.e., in the plane of the layer, in a direction perpendicular to the direction from the input end to the output end). For example, one or more (e.g., all) of the first layers and / or one or more (e.g., all) of the second layers may extend across the cavity.

[0074] In an embodiment, the cavity comprises a gap between the second material and the body of the amplifier, ie between the second material and the walls of the cavity.Thus, the second material may be spaced apart from the body of the amplifier, ie from the walls of the cavity.

[0075] In embodiments, when the cavity accommodates a plurality of layers, one or more (e.g., all) of these layers are spaced apart from the body of the amplifier, i.e., from the walls of the cavity. In embodiments, the cavity comprises gaps between the plurality of layers and the body of the amplifier, i.e., between the plurality of layers and the walls of the cavity. Thus, in these embodiments, all of the plurality of layers are spaced apart from the body of the amplifier.

[0076] When the cavity comprises a gap adjacent to a wall of the cavity, the gap may be filled with (e.g., comprise or consist of) a vacuum. In an embodiment, the gap comprises a buffer layer adjacent to the wall of the cavity (e.g., comprises (e.g., consists of) a fourth material). Thus, (the wall of) the cavity may be lined with a buffer layer. Similarly, the fourth material may be located between the second material and the body of the amplifier and / or between one or more of the plurality of layers and the body of the amplifier.

[0077] The gap and / or the buffer layer may help reflect the shock wave from the cavity walls, thereby reducing coupling of the shock wave into the body of the amplifier and instead focusing the shock wave towards the output end of the cavity, for example.

[0078] Preferably, the impact impedance of the fourth material is lower than the impact impedance of the first material. In an embodiment, the impact impedance of the fourth material is between the impact impedance of the first material and the impact impedance of the second material.

[0079] In an embodiment, the gap or the buffer layer has a constant thickness (in a direction perpendicular to the walls of the cavity). In an embodiment, the gap or the buffer layer has a variable thickness. For example, the thickness of the buffer layer may change (e.g., increase or decrease) from the input end to the output end of the cavity.

[0080] The various materials discussed herein (i.e., including the first material and the second material) may include any suitable and desired materials. In an embodiment, the first material includes a solid (e.g., is composed of a solid). In an embodiment, the first material includes a heavy (e.g., transition) metal (e.g., is composed of the metal), such as tantalum, platinum, tungsten, steel, or copper.

[0081] In an embodiment, the second material comprises a solid (e.g., consists of a solid). In an embodiment, the second material comprises a polymer (e.g., consists of the polymer), such as a thermopolymer, such as polymethyl methacrylate (PMMA). In an embodiment, the second material may comprise a liquid (e.g., consists of a liquid), such as water, ethanol or oil. In an embodiment where the plurality of layers comprises a plurality of second layers, one or more of the plurality of second layers may comprise a gas or a vacuum (e.g., consists of a gas or a vacuum).

[0082] In an embodiment, the cavity comprises a first sub-cavity and a second sub-cavity, the first sub-cavity and the second sub-cavity (each) being arranged between an input end of the cavity and an output end of the cavity, wherein the first sub-cavity comprises an input end and an output end, and the second sub-cavity comprises an input end and an output end, wherein the output end of the first sub-cavity is coupled to the input end of the second sub-cavity. Thus, the shape of the cavity can be configured to have two (or more) sub-cavities, wherein the first sub-cavity is arranged close to the input end of the cavity and the second sub-cavity is arranged close to the output end of the cavity.

[0083] This is itself considered to be novel and inventive and therefore, viewed from another aspect, the invention provides a system for producing localized energy concentration, the system comprising:

[0084] An amplifier for manipulating an input shock wave, wherein the amplifier comprises:

[0085] a body comprising a first material;

[0086] wherein the body defines a cavity for manipulating the input shock wave to produce a manipulated shock wave;

[0087] The cavity includes:

[0088] an input terminal for receiving the input shock wave incident on the amplifier;

[0089] an output end for outputting the manipulated shock wave from the cavity;

[0090] A first sub-cavity and a second sub-cavity, wherein the first sub-cavity and the second sub-cavity are arranged between an input end of the cavity and an output end of the cavity;

[0091] wherein the first sub-cavity comprises an input end and an output end, and the second sub-cavity comprises an input end and an output end; and

[0092] Wherein, the output end of the first sub-cavity is connected to the input end of the second sub-cavity;

[0093] wherein the system further comprises a target configured to contain the fuel; and

[0094] Therein, the amplifier and the target are configured such that the manipulated shock wave is arranged to be output from the amplifier so as to be incident on the target.

[0095] It will be appreciated that this aspect may (and preferably does) include one or more (eg all) of the preferred and optional features disclosed herein, for example, where applicable, in relation to other aspects and embodiments of the invention.

[0096] In an embodiment, the shape of the body is configured such that the cross-sectional area of ​​the output end of the first sub-cavity can be different (e.g., different size) from the cross-sectional area of ​​the input end of the second sub-cavity. For example, the cross-sectional area of ​​the output end of the first sub-cavity can be greater than the cross-sectional area of ​​the input end of the second sub-cavity.

[0097] However, in a preferred embodiment, the shape of the body is configured so that the cross-sectional area of ​​the output end of the first sub-cavity is smaller than the cross-sectional area of ​​the input end of the second sub-cavity. Shaping the cavity in this way to provide multiple sub-cavities helps to at least partially recapture the manipulated shock wave output from one (e.g., first) sub-cavity through the input end of the subsequent (e.g., second) sub-cavity. This can enable the shock wave to be further manipulated by (e.g., focused therein) the subsequent sub-cavity. This can help to reduce the energy of the input shock wave lost into the body of the amplifier, thereby helping to increase the energy transmitted in the manipulated shock wave output from the cavity.

[0098] Preferably, the cross-sectional area of ​​the input end of the first sub-cavity is larger than the cross-sectional area of ​​the output end of the first sub-cavity. Preferably, the cross-sectional area of ​​the input end of the second sub-cavity is larger than the cross-sectional area of ​​the output end of the second sub-cavity. In this way, both sub-cavities have a cross-sectional area that decreases from the respective input end to the output end, wherein the cross-sectional area increases from the output end of the first sub-cavity to the input end of the second sub-cavity.

[0099] In an embodiment, the cavity includes a plurality of sub-cavities, wherein each sub-cavity includes an input end and an output end, wherein the output end of each sub-cavity (except the output end of the sub-cavity close to the output end of the cavity) is connected to the input end of a subsequent sub-cavity (in a direction from the input end to the output end of the cavity), and wherein the shape of the body is configured such that the cross-sectional area of ​​the output end of each sub-cavity (except the output end of the sub-cavity close to the output end of the cavity) is smaller than the cross-sectional area of ​​the input end of the subsequent sub-cavity.

[0100] Therefore, preferably, the cavity has a plurality of connected sub-cavities from the input end of the cavity to the output end of the cavity along the direction between the input end of the cavity and the output end of the cavity. Preferably, the output end of each (e.g., first) sub-cavity completely overlaps (falls within the range of) the input end of the next (e.g., second) sub-cavity. Therefore, in an embodiment, the wall of the cavity includes a portion protruding inwardly to define (the input end and output end of) the sub-cavity.

[0101] In an embodiment, the cavity comprises a (e.g., first) layer between the first sub-cavity and the second sub-cavity, for example, the (e.g., first) layer extends across the output end of the first sub-cavity. When there are multiple sub-cavities, the cavity may comprise a first layer between (each pair of) adjacent sub-cavities. Separating the sub-cavities with a first layer may help to couple the shock waves between the sub-cavities.

[0102] Viewed from another aspect, the present invention provides a system for generating localized energy concentration, the system comprising:

[0103] An amplifier for manipulating an input shock wave, wherein the amplifier comprises:

[0104] an input face for receiving the input shock wave incident on the amplifier;

[0105] an output surface for outputting a manipulated shock wave from the amplifier; and

[0106] a plurality of (e.g. parallel) layers between the input face and the output face;

[0107] wherein the system further comprises a target configured to contain the fuel; and

[0108] Therein, the amplifier and the target are configured such that the manipulated shock wave is arranged to be output from the amplifier so as to be incident on the target.

[0109] It should be understood that this aspect may (preferably does) include one or more (e.g., all) of the preferred and optional features disclosed herein, e.g., where applicable, in connection with other aspects and embodiments of the invention. For example, one or more (e.g., all) of the preferred and optional features associated with the plurality of layers outlined herein may also apply to this aspect of the invention.

[0110] In an embodiment, any of the systems disclosed herein may include a mechanism for generating a shock wave to be incident on the amplifier.

[0111] In an embodiment, the mechanism for generating a shock wave comprises a mechanism configured to drive a projectile into an amplifier.

[0112] In an embodiment, the mechanism for generating the shock wave comprises an explosive drive mechanism, such as an air gun, configured to drive a projectile into an amplifier.

[0113] In an embodiment, the mechanism for generating the shock wave comprises an electromagnetic mechanism, such as a pulse power machine, configured to drive the projectile into the amplifier using electromagnetic force. For example, the mechanism may comprise a pulse power magnetically driven flyer configured to drive the projectile into the amplifier.

[0114] In an embodiment, the (e.g., electromagnetic) mechanism for generating shock waves comprises an electromagnetic direct drive mechanism configured to generate a Lorentz force in an electrode adjacent to the amplifier. In such an embodiment, the Lorentz force generates a shock wave in the electrode that is transmitted to the input of the amplifier.

[0115] In an embodiment, the mechanism for generating shock waves comprises a laser driven mechanism. The mechanism may include: an ablative layer adjacent to the input end of the amplifier cavity; and one or more lasers configured to ablate the ablative layer, thereby generating shock waves in the amplifier cavity. In an embodiment, the laser is incident directly on the ablative layer. In an embodiment, the laser is incident on the black body cavity surface, thereby generating x-rays that cover the ablative material and ablate it.

[0116] In an embodiment, the target comprises a chamber configured to contain a fuel.

[0117] In an embodiment, the chamber is configured to hold a gaseous fuel. In such an embodiment, the chamber may be airtight. In an embodiment, the fuel may be liquid, and thus the chamber may (e.g., only) be configured to hold liquid fuel. In an embodiment, the fuel may be solid, and thus the chamber may (e.g., only) be configured to hold solid fuel.

[0118] In an embodiment, the target is arranged to further manipulate the manipulated shock wave output from the amplifier.In an embodiment, the target may comprise a (eg conical) recess configured to direct the shock wave into an apex of the recess.

[0119] In an embodiment, the amplifier and the target are abutting, for example, at least a portion of the amplifier abuts at least a portion of the target (eg, at least a portion of an output face of the amplifier abuts at least a portion of the target).

[0120] In an embodiment, the amplifier and the target are physically spaced apart, ie, there is a space between the amplifier and the target, such that the amplifier and the target are not in (eg, direct) contact with each other.

[0121] In an embodiment, the system comprises a mount configured to hold the amplifier and the target in position relative to each other. In an embodiment, the mount comprises a clamp.

[0122] From another aspect, the present invention provides a method for generating local energy concentration using a system according to any one of the aspects or embodiments described herein, the method comprising:

[0123] generating a shock wave to be incident on the amplifier;

[0124] manipulating the shock wave using the amplifier; and

[0125] The steered shock wave is caused to be incident on the target.

[0126] It will be appreciated that this aspect may (and preferably does) include one or more (eg all) of the preferred and optional features disclosed herein, for example, where applicable, in relation to other aspects and embodiments of the invention.

[0127] It should be understood that the term "shock impedance" as used herein is intended to mean "the pressure that must be applied to a medium in order to impart a unit particle velocity to some portion of the medium" (Henderson, "On the refraction of shock waves," Journal of Fluid Mechanics, Vol. 198, January 1989, pp. 365-386). It is equal to the product of the impact velocity and the density of the unimpeded material.

[0128] It will be appreciated that the input shock wave may be formed outside the cavity and propagate into the input end of the cavity, but may additionally or alternatively be generated in the amplifier, for example by the amplifier being impacted (e.g. by a projectile). Both alternatives are encompassed by the term "input shock wave".

[0129] Embodiments of the system may be adapted to manipulate (e.g., amplify) shock waves to generate a localized energy concentration, with the goal of generating conditions suitable for nuclear fusion in a target. Thus, the target may (e.g., be configured to) contain a fusionable fuel, such as hydrogen, deuterium, and / or tritium in liquid, solid, and / or gaseous form. However, the system is not so limited, and may be used for other applications where the target contains (e.g., different types of) fuel.

[0130] Certain embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0131] Figure 1 A schematic diagram showing an apparatus according to an embodiment of the present invention is shown;

[0132] Figure 2 a. Figure 2 b. Figure 2 c and Figure 2 d shows four successive stages of the interaction of a shock wave with a device according to another embodiment of the invention;

[0133] Figure 3 shows a vertical cross section of an exemplary amplifier;

[0134] Figure 4a , Figure 4b , Figure 4c , Figure 4d , Figure 4e and Figure 4f shows the shock wave and Figure 3 Six successive stages of interaction of the amplifier.

[0135] Figure 5 A vertical cross section of the target is shown;

[0136] Figure 6 Shows Figure 5 Variations of the target;

[0137] Figure 7 Shows Figure 5 Variations of the target;

[0138] Figure 8 Shows Figure 5 Variations of the target;

[0139] Fig. 9 Shows Figure 5 Variations of the target;

[0140] Fig.10 Shows Figure 5 Variations of the target;

[0141] Fig.11 A vertical cross section of an alternative target is shown;

[0142] Fig.12 Shows Fig.11 Variations of the target;

[0143] Fig.13 A vertical cross section of another exemplary amplifier is shown.

[0144] Figure 1 An arrangement according to an embodiment of the invention is schematically shown. An amplifier 2 and a target 4 are provided. The target 4 is constructed of a solid medium 7 and defines a cavity 8 configured to contain a fusible fuel, such as liquid deuterium, solid deuterium or deuterium gas.

[0145] Figure 1 A substantially planar projectile 6 is shown. In the illustrated embodiment, the projectile 6 is a flat disc, but other projectiles may be used. The apparatus further comprises a mount 10 which supports both the amplifier 2 and the target 4. The mount 10 is arranged to support the amplifier 2 and the target 4 such that the amplifier 2 is disposed between the projectile 6 and the target 4. In this manner, the projectile 6 impacts the amplifier 4.

[0146] We will now refer specifically to Figure 2 a to Figure 2 The operation of this embodiment is described by referring to the four successive stages shown in FIG.

[0147] Initially, the projectile 6 impacts the amplifier 2. The projectile 6 may be propelled by, for example, a light air gun or a pulse power machine magnetically driven flyer. Figure 2 As seen in a, when the projectile 6 hits the amplifier 2, a planar shock wave 12 is generated in the amplifier 2. Figure 2As seen in b, as the shock wave 12 propagates through the amplifier 2, its speed, pressure and shape are manipulated by the internal design of the amplifier 2.

[0148] exist Figure 2 In Figure c, the shock wave 12 is emitted from the amplifier 2 and incident on the target 4. Figure 2 As the shock wave 12 propagates through the target 4, it impinges on the target fuel pocket 8, as shown in Figure d. This compresses the fuel within the target fuel pocket 8, causing intense local heating which may be sufficient to initiate fusion.

[0149] By positioning the amplifier 2 between the projectile 6 and the target 4, the shock wave 12 is modified and directed by the amplifier 2 such that the pressure distribution, velocity and duration of the shock wave pressure pulse emitted from the amplifier 2 are enhanced.

[0150] Further, by separately configuring the amplifier 2 and the target 4, a "plug and play" system is achieved, wherein different amplifier designs can be used with different target designs to achieve specific impact conditions. Further, for experimental purposes, alternative targets / amplifiers can be tested without reconfiguring the entire system.

[0151] Figure 3 A vertical cross section of the amplifier 2 is shown. It should be understood that Figure 3 The amplifier 2 shown is purely exemplary and other amplifier designs may be used in accordance with embodiments of the present invention.

[0152] The amplifier 2 includes a body 33 defining a hollow frustum-shaped cavity 35. The body 33 is formed of a material having a high surge impedance. In the illustrated embodiment, the body 33 is formed of a high surge impedance material such as tantalum, platinum, tungsten, steel, copper or other (e.g., heavy) metals. The cavity 35 contains a material 37 having a low surge impedance. The surge impedance of the cavity filling material 37 is lower than the surge impedance of the body 33. In the illustrated embodiment, the cavity filling material 37 is polymethyl methacrylate (PMMA), however, other materials are contemplated and the cavity filling material 37 may be a solid, liquid or gas.

[0153] The cavity 35 has an input end 39 configured to receive the shock wave, and an output end 311 configured to output the shock wave after the shock wave has propagated through the amplifier 32. The cross-sectional area of ​​the input end 39 is larger than the cross-sectional area of ​​the output end 311.

[0154] Figure 3A vertical cross section is shown, and in the illustrated embodiment, the amplifier 2 is rotationally symmetric. It will therefore be appreciated that the cavity 35 of the amplifier 2 is shaped as a conical frustum with a radius at the input end being greater than a radius at the output end. The amplifier 2 has an input face 310 proximate the input end 39 of the cavity 35, and an output face 312 proximate the output end 311 of the cavity 35.

[0155] Figure 3 An embodiment of an amplifier 2 is shown having an impedance matching layer 317 disposed on an input face 310 of the amplifier 2. The impedance matching layer 317 is a planar layer made of a material having an impact impedance between the impact impedance of the projectile 6 and the impact impedance of the cavity filling material 37. The impedance matching layer 317 improves the coupling efficiency into the amplifier 2 so that a higher proportion of the energy input into the amplifier 2 by the projectile 6 is transferred into the cavity filling material 37.

[0156] In an embodiment, the impedance matching layer 317 may be formed of a material having a variable impact impedance, such as a high impedance foam. The initial impact will encounter a relatively low impedance material, but will compress the foam so that subsequent impacts then encounter the compressed, and therefore high impedance, material. Such an impedance matching layer 317 may allow the use of low impedance projectiles 6, as the low impedance projectiles may effectively couple with the foam.

[0157] Now refer to Figures 4a to 4e The function of amplifier 2 is further explained. Figures 4a to 4e Shows the collision of projectile 6 Figure 4a Amplifier 2 is shown. Figure 4a Projectile 6 is shown impacting impedance matching layer 317. Figure 4b and Figure 4c In the embodiment, the resulting shock wave 12 passes through the impedance matching layer 317 and enters the cavity filling material 37. Through the reflection and superposition of the shock waves in the cavity 35, the pressure in the amplifier 2 increases.

[0158] When input into the cavity 35, as Figure 4d As seen in FIG. 1 , the input shock is reflected from the cavity wall 36 as an irregular shock reflection (Mach reflection), which propagates inward from the cavity wall 36 and eventually Figure 4e and Figure 4f The overlap is shown on the central axis of the cavity 35 .

[0159] The superposition of the radially symmetric waves on the central axis creates a high pressure point within the cavity filling material 37, which expands and interacts with the impinging Mach reflections to generate an axial quasi-planar Mach rod that propagates toward the output end 311 of the cavity 35. The wave eventually reaches the output end 311 of the cavity 35 and is ejected from the amplifier 2 at a higher pressure than the original input shock wave 12.

[0160] exist Figure 1 In the embodiment, the target 4 defines an internal chamber 8, which is configured to accommodate fusible fuel. In other embodiments, the chamber 8 may be formed as a recess in the surface of the target 4. In such embodiments, the surface of the target may be covered by a cover sheet to accommodate the fuel. Alternatively, in the case where the target abuts the amplifier, the cover sheet may not be required to accommodate the fuel.

[0161] Figure 5 A vertical cross-section of a target 54 is shown, the target defining a conical chamber 58. In the illustrated embodiment, the target is formed of gold, but other materials are contemplated, such as platinum, tungsten, steel, or aluminum.

[0162] In use, chamber 58 contains fusion fuel, such as liquid deuterium, solid deuterium or deuterium gas. Chamber 58 is sealed by cover sheet 53 placed on the surface of the target. When the manipulated shock wave propagates into chamber 58, the gas is compressed by the shock wave and pushed to point 59 of chamber 58.

[0163] Figure 6 Shows Figure 5 Variation of the target shown. Target 64 defines a chamber 68 that is shaped as a sawtooth cone such that the walls of chamber 68 are stepped. The sawtooth shape may aid in the shock wave capturing and thereby compressing the gaseous fuel.

[0164] Figure 7 Shows Figure 5 Variations of the target shown. Target 74 defines a bi-conical chamber 78. Chamber 78 is shaped as a cone, wherein the chamber wall includes two sections at different angles to the longitudinal axis of the chamber. In embodiments, more than two wall sections may be provided, for example, the chamber may be tri-conical. In embodiments, the chamber wall may be curved so that the chamber has a flared cone shape. Such a target may promote greater compression of the gaseous fuel because the shape of the chamber further focuses the shock wave after it leaves amplifier 2.

[0165] Figure 8 Shows Figure 5 A variation of the target shown. The chamber 88 includes two sections. The first section 81 is near the output end of the amplifier 2 and is bowl-shaped. The second section 82 is conical. Both the first section and the second section share the same central axis. The chamber 88 helps prevent injection and creates a converging shock above the second section 82, thereby compressing the gaseous fuel into the second section 82.

[0166] Fig. 9 Shows Figure 5Variation of the target shown. The chamber 98 of the target 94 has a layered curved chamber wall. The chamber 98 helps prevent ejection and produces a series of converging impacts. Further, the curved surface slows down the ejection of the cover sheet 53.

[0167] Fig.10 Shows Figure 5 The shape of the chamber 108 of the target 104 is set to be a cone, and the wall near the tip of the cone gradually transitions back toward the base of the cone, wherein the tip of the inverted cone is aligned with the central axis of the chamber 108. Fig.10 It can be seen in FIG. 1 that the vertical cross-section of the chamber 108 forms an approximate curved "W" shape. The inverted conical portion of the chamber wall guides the shock waves into the converging central section, thereby achieving higher dimensional convergence.

[0168] In all respects except those explicitly mentioned, the construction of the above-mentioned variant targets 64, 74, 84, 94, 104 is as described with respect to target 54.

[0169] Fig.11 An alternative target design is shown. Fig.11 A vertical cross section of a target 114 is shown, which defines a frustoconical chamber 118. The target 114 is formed of a high impedance material 7, which in the illustrated embodiment is tantalum. The chamber 118 is filled with a material having an impedance lower than that of the target material. In the illustrated embodiment, the chamber filling material is polymethyl methacrylate (PMMA). The chamber filling material defines an inverted conical subchamber 112 located at the narrow end of the chamber 118. In use, the subchamber 112 contains a fusible fuel, such as liquid deuterium, solid deuterium, or deuterium gas. When a manipulated shock wave propagates through the chamber filling material and enters the subchamber 112, the fuel is compressed by the shock wave.

[0170] Fig.12 Shows Fig.11 A variation of a target 124 is shown in FIG. 124 in which chamber 128 is conical and subchamber 122 has an arrow-shaped cross-section such that subchamber 122 is shaped as a cone with a conical depression at its base. The point of the cone of subchamber 128 is near the tip of the cone of chamber 128. In use, the shock may be driven toward the point of the base of the arrow (or the periphery of the base of the cone when considered in three dimensions), thereby preheating and precompressing the fuel, and then the shock converges at the tip of subchamber 122 and impacts the preheated and partially collapsed fuel.

[0171] Fig.13An amplifier 102 according to another embodiment of the present invention is shown. The amplifier 102 includes a body 133 formed of a series of parallel layers. These layers include a low impact impedance layer 130 formed of a low impact impedance material (such as PMMA or epoxy resin) and a high impact impedance layer 132 formed of a high impact impedance material (such as tantalum, tungsten, steel, copper or platinum). As a minimum requirement, the high impact impedance layer 132 is formed of a material having a higher impact impedance than the material forming the low impact impedance layer.

[0172] The parallel layers alternate layer by layer from low impact impedance layers 130 to high impact impedance layers 132. In the illustrated embodiment, the input layer 134 forming the input face 110 of the amplifier 102 is a low impact impedance layer 130. This is because the input face 110 formed by the high impact impedance layer 132 will cause a larger portion of the shock wave to be reflected by the input face 110 and therefore not transmitted into the amplifier 102. However, alternatives are also contemplated.

[0173] In the illustrated embodiment, the thickness of the high impact impedance layer 132 and the low impact impedance layer 130 gradually decreases from the input face 110 to the output face. However, in an embodiment, the thickness of each of the high impact impedance layers 132 is equal. It should be understood that although the thickness can vary between layers, each individual layer has a uniform thickness across its width.

[0174] The layers are arranged so that a shock wave generated at the input face 110 of the amplifier 102 of the layer stack reverberates within the layer stack due to reflections from the high shock impedance layer 132, thereby creating regions of constructive and destructive interference as the shock waves pass each other. When a shock enters the high shock impedance layer 132 from the low shock impedance layer 130, a portion of the shock is transmitted into the high shock impedance layer 132, while a portion is reflected back into the low shock impedance layer 130.

[0175] The portion in the low impact impedance layer 130 is accelerated as it now travels through the pre-impact material, the impact portion is then reflected from the boundary at the input end of the low impact impedance layer, and since it has been accelerated, the reflected portion eventually catches up with the portion of the impact that was originally transmitted into the high impact impedance layer 132. With the arrangement of the low impact impedance layer 130 and the high impact impedance layer 132, the amplifier 102 can be arranged so that multiple impact signatures are superimposed on the output face 112 of the amplifier 102, thereby generating a transient high impact pressure state that can enter a target adjacent to the amplifier output end 112.

[0176] In the illustrated embodiment, all high impact impedance layers 132 are formed of the same material, and all low impact impedance layers 130 are formed of the same material. In an embodiment, different low impact impedance layers 130 may use different low impact impedance materials, and different high impact impedance layers 132 may use different high impact impedance materials.

[0177] In each of the above embodiments, the figures shown are vertical cross-sections of the three-dimensional volume of gas and target surface, thus depicting a rotationally symmetric embodiment. However, this is not essential to the present invention.

Claims

1. A system for generating local energy concentration, comprising: an amplifier arranged to manipulate one or more of the velocity, pressure or shape of an input shock wave, wherein the amplifier comprises: a body comprising a first material; wherein the body defines a cavity for manipulating the input shock wave to produce a manipulated shock wave; Wherein, the cavity comprises: an input for receiving said input shock wave incident on said amplifier; and an output for outputting a manipulated shock wave, wherein the system further comprises a target configured to contain the fuel; and Therein, the amplifier and the target are configured such that the manipulated shock wave is arranged to be output from the amplifier so as to be incident on the target.

2. The system of claim 1, wherein: The cavity contains a second material having an impact impedance lower than that of the first material.

3. The system of claim 1 or 2, wherein: The cross-sectional area of ​​the input end is larger than the cross-sectional area of ​​the output end.

4. A system as claimed in claim 1, 2 or 3, wherein: The cavity is frustum-shaped.

5. A system as claimed in any one of the preceding claims, wherein: The cavity comprises a conical frustum.

6. A system as claimed in any preceding claim, comprising means for generating a shock wave to be incident on the amplifier.

7. The system of claim 6, wherein: The means for generating a shock wave comprises a mechanism arranged to drive a projectile into the amplifier.

8. The system of claim 6 or 7, wherein: The mechanism comprises an electromagnetic mechanism.

9. The system of claim 6 or 7, wherein: The mechanism includes an explosive drive mechanism.

10. The system of claim 6, wherein: The mechanism includes an electromagnetic direct drive mechanism configured to generate a Lorentz force in an electrode adjacent to the amplifier.

11. The system of claim 6, wherein: The mechanism for generating shock waves includes a laser driven mechanism including: an ablative layer adjacent to an input end of the amplifier cavity component; and one or more lasers configured to ablate the ablative layer.

12. A system as claimed in any preceding claim, wherein: The target includes a chamber configured to contain a fuel.

13. The system of claim 12, wherein: The chamber is configured to contain a gaseous fuel.

14. A system as claimed in any preceding claim, wherein: The target is arranged to further manipulate the manipulated shock wave output from the amplifier.

15. A system as claimed in any preceding claim, wherein: The amplifier and the target are in abutment.

16. The system of any one of claims 1 to 14, wherein: The amplifier and the target are physically spaced apart.

17. The system of any preceding claim, comprising a mount configured to hold the amplifier and the target in position relative to each other.

18. A system for producing localized energy concentration, comprising: An amplifier for manipulating an input shock wave, wherein the amplifier comprises: a body comprising a first material; wherein the body defines a cavity for manipulating the input shock wave to produce a manipulated shock wave; Wherein, the cavity comprises: an input for receiving the input shock wave incident on the amplifier; and an output for outputting the manipulated shock wave from the cavity; wherein the cavity contains a second material, the impact impedance of the second material is lower than the impact impedance of the first material; and wherein the cavity includes a space between an input end of the cavity and an input surface of the second material; wherein the system further comprises a target configured to contain the fuel; and Therein, the amplifier and the target are configured such that the manipulated shock wave is arranged to be output from the amplifier so as to be incident on the target.

19. A system for producing localized energy concentration, comprising: An amplifier for manipulating an input shock wave, wherein the amplifier comprises: a body comprising a first material; wherein the body defines a cavity for manipulating the input shock wave to produce a manipulated shock wave; Wherein, the cavity comprises: an input terminal for receiving the input shock wave incident on the amplifier; an output for outputting the manipulated shock wave from the cavity; and a plurality of layers between the input and the output; wherein one or more of the plurality of layers comprises a second material, the impact impedance of the second material being lower than the impact impedance of the first material; wherein the system further comprises a target configured to contain the fuel; and Therein, the amplifier and the target are configured such that the manipulated shock wave is arranged to be output from the amplifier so as to be incident on the target.

20. A system for producing localized energy concentration, comprising: An amplifier for manipulating an input shock wave, wherein the amplifier comprises: a body comprising a first material; wherein the body defines a cavity for manipulating the input shock wave to produce a manipulated shock wave; Wherein, the cavity comprises: an input terminal for receiving the input shock wave incident on the amplifier; an output for outputting the manipulated shock wave from the cavity; a first sub-cavity and a second sub-cavity, wherein the first sub-cavity and the second sub-cavity are arranged between an input end of the cavity and an output end of the cavity; wherein the first sub-cavity includes an input end and an output end, and the second sub-cavity includes an input end and an output end; wherein the output end of the first sub-cavity is coupled to the input end of the second sub-cavity; wherein the system further comprises a target configured to contain fuel; and Therein, the amplifier and the target are configured such that the manipulated shock wave is arranged to be output from the amplifier so as to be incident on the target.

21. A system for producing localized energy concentration, comprising: An amplifier for manipulating an input shock wave, wherein the amplifier comprises: an input face for receiving said input shock wave incident on said amplifier; an output surface for outputting a manipulated shock wave from the amplifier; and a plurality of layers between the input face and the output face; wherein the system further comprises a target configured to contain the fuel; and Therein, the amplifier and the target are configured such that the manipulated shock wave is arranged to be output from the amplifier so as to be incident on the target.

22. A method of producing localized energy concentration using a system as claimed in any one of the preceding claims, wherein: The method comprises: generating a shock wave to be incident on the amplifier; manipulating the shock wave using the amplifier; and The steered shock wave is caused to be incident on the target.

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