WO2010114360A1

WO2010114360A1 - Apparatus for fusing nuclei of hydrogen isotopes

Info

Publication number: WO2010114360A1
Application number: PCT/NL2009/000213
Authority: WO
Inventors: Bernard Jozef Reits
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-09-24
Filing date: 2009-11-06
Publication date: 2010-10-07
Anticipated expiration: 2012-03-24

Abstract

The invention relates to an apparatus for fusing nuclei of hydrogen isotopes. The apparatus consists of a spherically shaped vessel (1), filled with a medium containing hydrogen isotopes, and groups of shockwave generators (2a, 2b, 2c, 2d) for generating a series of separate, spherical shockwaves in the vessel (1) that converge towards a centre (5) of the vessel (1). Time delays between the successive spherical shockwaves are chosen such that all shockwaves arrive simultaneously in the centre (5) of the spherically shaped vessel (1). The centre (5) may contain a tiny sphere, made of iron with a lithium containing cladding.

Description

Apparatus for fusing nuclei of hydrogen isotopes

The invention relates to an apparatus for fusing nuclei of hydrogen isotopes, comprising a spherically shaped vessel filled with a medium and means for generating a spherical Shockwave inside the vessel that converges towards a centre of the vessel.

An apparatus of this kind has been described in US-A- 3,346,458. In the known apparatus, the Shockwave is generated in a vessel filled with a gaseous medium, by igniting a gas mixture near the inner surface. A resulting shock wave, running from the inner surface towards the centre, is used for compressing a quantity of solid fuel present in the centre, in order to bring about a thermonuclear reaction.

More recently an apparatus of this kind has been described in US2006/0198487A1. In this apparatus, a Shockwave running towards the centre is generated in a vessel filled with a liquid medium with the aid of a large number of movable pistons .

The problem with these known arrangements is that single Shockwaves are generated, a leading edge of which will become steeper while passing the medium. For a converging shock wave having a steep leading edge it is known in the art that a large fraction of the energy contained in the shock wave will be converted into heat. Apart from the losses as such this limits the compression attainable in the medium near the centre.

The apparatus according to the invention substantially obviates this disadvantage. It is characterised in that the means are arranged for generating a series of successive, separate spherical Shockwaves. A pressure increase in the medium caused by the first Shockwave results in an increased propagation speed for the second Shockwave, an even more increased propagation speed for the third Shockwave and so on, which means that the successive Shockwaves will catch up one another. Preferably, a time delay between the successive Shockwaves is chosen such that the Shockwaves will reach simultaneously the centre of the spherically shaped vessel. The result is that the medium in the centre will undergo a substantially adiabatic compression, during which a pressure such high and eventually a temperature such high is reached that nuclei of hydrogen isotopes present in the medium may fuse. An important additional advantage is that for a series of stepwise pressure increases in the medium the growth of Rayleigh-Taylor instabilities will be reduced, as only during a very short time and only very close to the centre very large density gradients will occur.

A favourable embodiment of the apparatus is characterised in that the amplitudes of successive Shockwaves increase. Preferably, the amplitudes of successive Shockwaves increase at least substantially exponentially. It can be proved that in this case the compression will be perfectly adiabatic .

A further favourable embodiment with which a precise radial symmetry of the successive Shockwaves can be guaranteed is characterised in that the means comprise a large set of Shockwave generators, mounted onto or inside a wall of the vessel and distributed substantially uniform over the wall of the vessel. It may be noted here that it is not necessary to cover the entire wall with Shockwave generators. For obtaining a high precision spherical Shockwave it is sufficient to mount for example a hundred Shockwave generators onto or inside the wall, the parameters of which are chosen in a manner well known in the art such that the separate Shockwaves will at least near the centre unite and form a closed spherical Shockwave .

Existing Shockwave generators cannot produce very powerful successive Shockwaves at very short time intervals. A favourable embodiment of the apparatus with which it is nevertheless possible to generate very powerful successive Shockwaves with a precise radial symmetry and with mutually very short time intervals is characterised in that the set of Shockwave generators consists of a number of disjoint subsets of Shockwave generators, the Shockwave generators within each subset being distributed substantially uniform over the wall. In this way each closed spherical Shockwave is generated by a subset of Shockwave generators, which implies that every discrete Shockwave generator will contribute to only one spherical Shockwave. For every subset the parameters of the generated Shockwaves are to be chosen in a manner well known in the art so that the separate Shockwaves will at least near the centre unite and form a closed spherical Shockwave.

The apparatus as described in the previous paragraphs can be used for generating single fusion reactions, for example in order to optimise process parameters, like the optimal time delays between the successive Shockwaves and the optimal amplitudes of the successive Shockwaves. Once a fusion reaction can be obtained in a reproducible manner, it is advantageous to arrange the apparatus such that the fusion reaction will be maintained at least during some time, in such a way that energy may be extracted from the fusion reactor. A favourable embodiment of the apparatus with which a semi-continuous fusion reaction can be realised is characterised in that the means also comprise a large set of reflectors, mounted onto or inside the wall of the vessel and distributed substantially uniform over the wall of the vessel, with which new successive closed spherical Shockwaves can be generated. A spherical Shockwave emanating from the centre, originally generated by Shockwave generators, will be reflected by the reflectors and generate a new spherical Shockwave.

Preferably, the set of reflectors consists of a number of disjoint subsets of reflectors, the reflectors within each subset being equal and being distributed substantially uniform over the wall, such that each subset generates precisely one spherical Shockwave. By carefully selecting the surface area and the position of the different reflectors one may generate in this way a series of successive separate spherical Shockwaves which realise an adiabatic compression in the medium in the centre of the vessel.

A further favourable embodiment is characterised in that a Shockwave generator comprises an actuator, coupled to a diaphragm forming part of the wall. In this way, the vessel becomes actually a hermetically closed vessel that can be filed with all kinds of medium. Preferably the medium consists at least substantially of heavy water, to which preferably a lithium compound and/or a beryllium compound has been added. Heavy water contains much deuterium, which forms the basis for the fusion reaction. As the medium is the fuel here, there will be no problems associated with unwanted reflections of the Shockwave. Moreover, the medium forms an excellent shielding for the radiation that is produced during the fusion reaction and the lithium compound and/or the beryllium compound can easily be dissolved in the heavy water. Neutrons that are liberated during the fusion reaction will react with the lithium atoms and/or the beryllium atoms, which results in a substantially increased energy production. Moreover, the hydrogen isotope tritium is produced, which may contribute to the fusion reaction and boost the fusion reaction. A favourable embodiment according to a further aspect of the invention is characterised in that the centre of the spherically shaped vessel contains a sphere having a diameter of 0,5 to 1,5 millimetres. The sphere may be kept in place with an electromagnetic suspension system for example. The advantage is that the converging spherical Shockwave will reflect on the surface of the sphere, which increases the pressure in the medium near the surface of the sphere. Preferably, the sphere consists of a core made of a high density material having a lithium containing cladding. The high density material, for example iron, guarantees a substantially complete reflection of the converging spherical Shockwave, while the cladding will produce tritium near the surface of the sphere, because roughly 50 percent of the neutrons produced by previous or momentary fusion reactions will hit the lithium containing layer. The sphere may therefore be seen as a physical catalyst for the fusion reactions to take place.

The invention will now be further explained wit a reference to the following figures, in which:

Fig. 1 schematically represents a possible embodiment of an apparatus for generating a spherical

Shockwave in cross section; Fig. 2 schematically represents a possible embodiment for generating four spherical Shockwaves in cross section; FFiigg.. 33AA schematically represents a regular icosahedron;

Fig . 3B schematically represents a geodetic sphere, based on a regular icosahedron;

Fig . 4A schematically represents the amplitudes of four spherical Shockwaves; FFiigg.. 44BB schematically represents the summed Shockwaves as observed in the medium; Fig. 4C schematically represents the summed Shockwaves as observed in the medium near the centre; Fig. 5A schematically represents a segment of a sphere based on a regular icosahedron with five reflectors;

Fig. 5B schematically represents a segment of a sphere based on a regular icosahedron with five reflectors and a Shockwave generator;

Fig. 5C schematically represents part of the wall of a spherically shaped vessel with reflectors and a

Shockwave generator in side view; Fig. 6A schematically represents a possible embodiment of a Shockwave generator in cross section; Fig. 6B schematically represents this Shockwave generator in front view;

Fig. 7A schematically represents an alternative embodiment of a Shockwave generator in cross section;

Fig. 7B schematically represents this Shockwave generator in front view.

Fig. 1 schematically represents a possible embodiment of an apparatus for generating a spherical Shockwave in cross section. The apparatus consists of a spherically shaped vessel 1 having a diameter of for example 1.5 meter, manufactured of for example stainless steel and provided with a group of Shockwave generators 2, each provided with a metal foil 3 which in fact forms part of the wall of vessel 1. Shockwave generators 2 are distributed evenly over the surface of vessel 1 and they are connected to a steering unit 4, in such a manner that Shockwave generators 2 can simultaneously generate a Shockwave in a liquid medium contained in vessel 1. The separate Shockwaves merge to one spherical Shockwave which converges towards a centre 5, in the process of which it will become steeper while its amplitude increases. This results in the medium in centre 5 being heavily compressed and heated during a short time span. Subsequently, an attenuated Shockwave will diverge from centre 5 and reflect against the wall of vessel 1, after which the process will be repeated. The attenuation factor depends on the type of compression that takes place in centre 5. If it is a true adiabatic compression, then the attenuation will be minimal. If it is a non-adiabatic compression, then part of the energy contained in the Shockwave will prematurely be converted into heat, which results in an incomplete compression in centre 5 and substantial attenuation of the reflected Shockwave. It is well known in the art that a single converging Shockwave with a steep leading edge cannot result in an adiabatic compression. For obtaining a perfect adiabatic compression, the amplitude of the converging Shockwave should rise exponentially. In order to approximate an adiabatic compression, it is sufficient to generate a number of converging Shockwaves of which the successive amplitudes exponentially increase.

Fig. 2 schematically represents a possible embodiment for generating four spherical Shockwaves in cross section. The apparatus consists of a spherically shaped vessel 1 having a diameter of for example 1.5 meter, manufactured of for example stainless steel, in which four subgroups of

Shockwave generators 2a, 2b, 2c, 2d are mounted, each provided with a metal foil 3 which in fact forms part of the wall of vessel 1. Subgroup 2a is connected to a steering unit 4a, subgroup 2b is connected to a steering unit 4b, subgroup 2c is connected to a steering unit 4c and subgroup 2d is connected to a steering unit 4d. Each subgroup of Shockwave generators is distributed evenly over the surface of vessel 1 and the Shockwave generators within each subgroup can simultaneously generate a Shockwave in a liquid medium contained in vessel 1. The separate Shockwaves merge to one spherical Shockwave which converges towards a centre 5, in the process of which it will become steeper while its amplitude increases. According to the invention the steering units 4a, 4b, 4c, 4d are subsequently triggered with previously determined time delays. As the second spherical Shockwave propagates in a medium having a larger density than the first Shockwave, its propagation speed will be higher. For the third and fourth spherical Shockwave the propagation speed will be increasingly higher. By well chosen time delays, the four Shockwaves will reach centre 5 exactly simultaneously. At that moment, the medium in centre 5 will be compressed and heated for a short period of time. Subsequently, a single attenuated spherical Shockwave will diverge from centre 5 and reflect against the wall of vessel 1. If the mutual ratios of the amplitudes of the successive spherical Shockwaves are well chosen, the compression in centre 5 will be much more powerful compared with the compression obtained by just one spherical Shockwave. Also the amplitude of the diverging Shockwave will be larger. In the embodiment shown here, centre 5 consists of a sphere made of iron, having a diameter of 1 millimetre, with a lithium containing cladding having a thickness of 0,2 millimetres, kept in place with an electromagnetic suspension system not shown in the figure. The iron sphere guarantees a substantially complete reflection of the converging spherical Shockwave, in the process of which the pressure in the medium will double, while the lithium containing cladding will produce tritium on the surface of the sphere with the aid of neutrons produced by previous or momentary fusion reactions. The cladding may for example consist of lithium cobalt oxide, electroplated on the iron sphere.

For the fusion of hydrogen isotopes, very powerful spherical Shockwaves are needed, generated by a set of Shockwave generators subdivided in for example four subsets that each produce one spherical Shockwave. In order to evenly distribute the set of Shockwave generators over the surface area of vessel 1, one may start for example with a regular polyhedron, which forms the basis for a geodetic dome. Fig. 3A schematically represents a regular icosahedron 6, which forms the basis for the embodiment shown here. Fig. 3B schematically represents a regular icosahedron based on a geodetic dome 7, the vertices of which coincide with vessel 1. Every triangle of regular icosahedron 6 defines a subsurface of dome 7. This subsurface is divided into four subsurfaces 8a, 8b, 8c, 8d, the vertices of which coincide with vessel 1. In the centres of subsurfaces 8a, 8b, 8c, 8d Shockwave generators 2a, 2b, 2c, 2d are mounted, being elements of four subsets of Shockwave generators. This means that every spherical Shockwave will be generated by twenty Shockwave generators. It is also possible to again subdivide subsurfaces 8a, 8b, 8c, 8d into for example four subsubsurfaces, each provided with a Shockwave generator. In that case every spherical Shockwave will be generated by eighty Shockwave generators.

Fig. 4A schematically represents the amplitudes of four spherical Shockwaves 9a, 9b, 9c, 9d, generated by subgroups of Shockwave generators 2a, 2b, 2c, 2d. First Shockwave 9a passes, having a relatively small amplitude, shortly afterwards Shockwave 9b passes having a larger amplitude and so on. After Shockwave 9a has been passed, the pressure in the medium and the density of the medium have been increased. For that reason the propagation speed of Shockwave 9b and the subsequent Shockwaves will increase.

Fig. 4B schematically represents the summed Shockwaves 9a, 9b, 9c, 9d as observed in the medium, for example at a distance of 50 centimetres from centre 5. It can be seen that the slope of the separate Shockwaves has increased and that the summed Shockwaves approximate an exponentially growing Shockwave. Fig. 4C schematically represents the summed Shockwaves 9a, 9b, 9c, 9d as observed in the medium near the centre. It can be seen that the slope of the separate Shockwaves has further increased and that the summed Shockwaves approximate a steeper exponentially growing Shockwave. The slope will further increase, until in centre 5 the slopes of the separate Shockwaves will completely merge. In this way an almost perfect adiabatic compression can be realised, followed by an almost perfect adiabatic expansion, after which a single spherical Shockwave will start travelling into the direction of the wall of vessel 1. As we have an adiabatic compression followed by an adiabatic expansion, the energy contained in the expanding Shockwave will be comparable with the energy contained in the four spherical Shockwaves 9a, 9b, 9c, 9d. If nuclear fusion has taken place, the energy of the expanding Shockwave may even be larger. During nuclear fusion, very fast particles will be liberated which carry away the energy set free in the fusion process. Almost all particles have a relatively large mean free path, which means that they do not contribute to the energy of the expanding Shockwave. About ten percent of the liberated energy is carried away by particles having a relatively short mean free path. These particles will contribute to the energy of the expanding Shockwave.

Fig. 5A schematically shows a sphere 10 which envelops a regular icosahedron, not shown. The vertices of the regular icosahedron define subsurfaces 11 on sphere 10. Onto every subsurface 11 five reflectors 12a, 12b, 12c, 12d, 12e have been mounted, in such a way that the surface area of subsurface 11 is optimally covered. Reflector 12a is the smallest and it is located at the smallest distance of centre 5, reflector 12b is somewhat bigger and it is located at a slightly larger distance and so on. All reflectors substantially coincide with the wall of vessel 1 and the differences in distance amount for example to a few millimetres, dependent upon the size of vessel 1 and type medium used. If in this situation an expanding spherical Shockwave emanating from centre 5 hits reflectors 12a, 12b, 12c,12d,12e, then first reflectors 12a will generate in combination a spherical Shockwave, subsequently reflectors 12b will do so and so on. We are now again in the situation as described with a reference to Fig. 4, in this case with five separate Shockwaves, which means that again an adiabatic compression may take place.

Fig. 5B schematically represents a segment of a sphere 10, with reflector 12e being provided with a Shockwave generator 2 with which initially a spherical Shockwave can be generated. Subsequently, reflectors 12a, 12b, 12c, 12d, 12e may reflect this Shockwave over and over again, in the process of which the amplitude of Shockwave will decrease or on the contrary increase if nuclear fusion is taking place to a sufficiently large extent. Of course it is possible to provide all reflectors 12a, 12b, 12c, 12d, 12e with a Shockwave generator, in which case the very first compression may be a substantially adiabatic compression too. Moreover it is possible to increase the number of reflectors on subsurface 11 or to decrease it. With a larger number of reflectors a more precise approximation of an exponential function can be made and a higher compression ratio may be realised. It is also possible to divide subsurfaces 11 of sphere 10 into for example four subsubsurfaces, each provided with for example five reflectors 12a, 12b, 12c, 12d, 12e . In that case each spherical Shockwave will be realised with eighty reflectors. The reflectors may for example consist of metal disks with five different diameters and heights, which are mounted onto the inside of the wall of vessel 1. Between the reflectors the wall of vessel 1 may be covered with a shock-absorbing layer or one may use the reflection on the wall for generating an additional spherical Shockwave.

Fig. 5C schematically shows part of the wall of a spherical vessel 1 with reflectors 12a,..12e, the reflectors 12e each being provided with a Shockwave generator 2. An expanding Shockwave emanating from centre 5 will first reflect from reflectors 12a and generate in this way a first spherical Shockwave, next reflect from reflectors 12b and so on.

Fig. 6A schematically represents a possible embodiment of a Shockwave generator 2 in cross section. Shockwave generator 2 consists of a hollow cylindrical body 13, on the outside provided with a thread so that it can be screwed into an opening of vessel 1. A front side of Shockwave generator 2 is closed with a copper foil 14 that is welded onto cylindrical body 13. Under foil 14, a thin disc 15 made of an insulating material is placed and underneath a disc coil 16 is placed which is supported by a thick disc 17 made of an insulating material. In the space underneath plate 17 a capacitor 18 is placed which can be charged via a connector 19 and a charge resistor 20, as well as a thyratron 21 and a series resistor 22. When thyratron 21 is triggered via a connector 23, capacitor 18 is discharged via disc coil 16 and series resistor 22. As a result, foil 14 is ejected outwards with a great force, therewith generating a Shockwave in the medium present in vessel 1. Series resistor 22 is chosen such that the discharge is critically damped. Shockwave generators of this type are known as such. They are used for example for disintegrating calculi inside a patient, who is placed in a bath provided with Shockwave generators for that purpose.

Fig. 6B schematically shows this Shockwave generator 2 in front view, with body 13, foil 14 and disc coil 16, represented with a dotted line. Fig. 7A schematically represents an alternative embodiment of a Shockwave generator 2 in cross section. Shockwave generator 2 consists of a rod-shaped object 24, on the outside provided with a thread so that it can be screwed into an opening of vessel 1. In rod-shaped object 24, a parabolically shaped combustion chamber 25 is made, a front of which is closed with a stainless steel foil 26 that is welded onto rod-shaped object 24 and that is supported by a grid 27 which is sufficiently strong to withstand the pressure inside vessel 1. Via a valve 28 a combustible gas may flow into combustion chamber 25 and via three-way valve 29 combustion chamber 25 may be evacuated or oxygen may flow into combustion chamber 25. After combustion chamber 25 has been filled with a suitable gas mixture, the gas mixture is ignited near the focal point of combustion chamber 25 with a spark plug 30 via a connector 31. In this way, a Shockwave is generated in the medium present in vessel 1. In rod-shaped object 24, a spring loaded overpressure valve 32 is accommodated, which prevents a static pressure build up in combustion chamber 25.

Fig. 7B schematically represents this Shockwave generator 2 in front view, with rod-shaped object 24, foil 26 and grid 27.

For both embodiments, a desired radiation diagram for the shock wave may be obtained by providing disc coil 16 or grid 27 with a radius of curvature, such that also foil 14 or foil 26 will assume this desired radius of curvature. Moreover the pitch of disc coil 16 may be varied and the mesh width of grid 27 may be varied in order to realise a desired tapering of the Shockwave. The amplitude of the Shockwave may be varied by selecting the charge voltage of capacitor 18 or the pressure of the gas mixture in combustion chamber 25. While being in use, a spherical Shockwave with an energy of for example 1 kilojoule oscillates in vessel 1 with a frequency of about 1 kilohertz. For each period, the losses are estimated to be 20 percent. These losses must be compensated for by nuclear fusion. As the contribution of a fusion reaction to the oscillation amounts to typically 10 percent, each fusion reaction must generate 2 kilojoules. Therefore the apparatus must generate typically 2 mega- watts in order to maintain the oscillation. Energy may be extracted in the form of heat, but it is also possible to convert part of the energy stored in the Shockwave directly to energy.

Claims

1. Apparatus for fusing nuclei of hydrogen isotopes, comprising a spherically shaped vessel filled with a medium and means for generating a spherical Shockwave inside the vessel that converges towards a centre of the vessel, characterised in that the means are arranged for generating a series of successive, separate spherical Shockwaves.

2. Apparatus according to claim 1, characterised in that a time delay between successive Shockwaves is chosen such that the Shockwaves simultaneously reach a centre of the spherically shaped vessel.

3. Apparatus according to claim 2, characterised in that the amplitudes of successive Shockwaves increase.

4. Apparatus according to claim 3, characterised in that the amplitudes of successive Shockwaves increase at least substantially exponentially.

5. Apparatus according to claim 4, characterised in that the means comprise a large set of Shockwave generators, mounted onto or inside a wall of the vessel and distributed substantially uniform over the wall of the vessel.

6. Apparatus according to claim 5, characterised in that the set of Shockwave generators consists of a number of disjoint subsets of Shockwave generators, the Shockwave generators within each subset being distributed substantially uniform over the wall.

7. Apparatus according to claim 6, characterised in that the means also comprise a large set of reflectors, mounted onto or inside the wall of the vessel and distributed substantially uniform over the wall of the vessel.

8. Apparatus according to claim 7, characterised in that the set of reflectors consists of a number of disjoint subsets of reflectors, the reflectors within each subset being equal and being distributed substantially uniform over the wall.

9. Apparatus according to one of the claims 5 to 8, characterised in that a Shockwave generator comprises an actuator, coupled to a diaphragm forming part of the wall.

10. Apparatus according to one of the previous claims, characterised in that the medium consists at least substantially of heavy water, to which a lithium compound and/or a beryllium compound has been added.

11. Apparatus according to one of the previous claims, characterised in that the centre of the spherically shaped vessel contains a sphere having a diameter of 0,5 to 1,5 millimetres.

12. Apparatus according to claim 11, characterised in that the sphere consists of a core made of a high density material and a lithium containing cladding.