Nano-structured nuclear radiation shielding

BACKGROUND

The channeling experiments proven that the radiation may be trapped inside atomic lattices and driven in a similar manner with that the microwave and optical radiation is driven through the wave-guides and respectively optic fiber. Charged particles and X-ray channeling has already reached the applications in accelerator and space technology.

The new development based on nano-structures pushes the limits of channeling towards the high-energy radiation domain driving to applications of an exceptional importance.

The present solution of using complex nano-structures that can be electrically controlled open the way to a new revolution in nuclear energy.

SUMMARY

A novel material that comprises a plurality of nano-structures that is able to trap and guide nuclear radiation in a controlled manner. The material is made of a plurality of controlled grown nano-structures, able to gyrate the radiation at desired angle. The material may be build in hetero-structures inserting electric sensitive materials than make its channeling properties vary.

A device made using such material that controls the radiation direction possible of being used as control device in nuclear reactor replacing the control rods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1—The principia of radiation shielding

FIG. 2—The radiation degradation and absorption

FIG. 3—The principia of multilayer decreasing energy resonant absorption attenuation

FIG. 4—The radiation gyration schematics by bended micro wave-guides and nano-fibers

FIG. 5—The bended molecular wave-guide made in multi-layered clustered material

FIG. 6—The radiation funneling mechanism by channeling

FIG. 7—X gamma and neutrons radiation switch

FIG. 8—The “miu” radiation switch with digital control

FIG. 9—A monolayer “miu” switch schematics

FIG. 10—The nuclear reactor control by variable transmission “miu” switch shielding

FIG. 11—The use of a radiation funneling shielding to shield a plasma focused fission device

FIG. 12—A space-shuttle radiation-shielding device for charged particles and X, gamma rays

FIG. 13—Multi-focusing multi-layer

FIG. 14—Space imaging device

FIG. 15—Adapted nano-tube wave-guide example

FIG. 16—The complete shielding structure

FIG. 17—The atomic level low energy gamma ray channeling

FIG. 18—The radiation selective extractor/gyrator

FIG. 19—The radiation raincoat-like individual protective equipment

FIG. 20—Mobile miniaturized nuclear reactor

FIG. 21—Mobile nuclear powered SUV

DETAILED DESCRIPTION

FIG. 1—Shows the method of radiation shielding based on classical and non-classical approaches. The sources 107 are supposed to emit radiation in space with a spherical symmetry, having the intensity at a distance r from the source given by formula presented in the figure where A is the source's activity for the radiation k. This is the radiation intensity that hits a shielding element on the external surface. The ray 104 represents the radiation Pointing vector hitting the shield and having the intensity on its surface I₀^k. The shield 103 has a thickness made from elemental layers “i′” 109 a volume content 101 and an associated coordinates system 102.

At the contact with the surface 103 the radiation 104 is reflected 105 and refracted 106. The ration Ir 105 per Io 104 gives the “albedo” figure also called the reflection coefficient, while the It 106 versus I0104 ratio gives the transmitted radiation. In current nuclear radiation calculations It is assumed equal with I0 because the reflection factor is smaller than 2% and is depending on incidence angle and energy. The classical absorption theory based on random interaction is following the exponential law having the absorption coefficient depending on material, density and radiation energy. The absorption length is defined as being the length where It becomes 1/e from Io or the sum at the exponent of the absorption factors equals 1.

There is important to understand that the absorbed radiation does not disappear, it is considered absorbed because it disappears from its original group “k” but the absorption location becomes a source reemitting the absorbed energies in other forms depending on the mechanism of interaction. The quantum scattering is covering the

Thompson and Compton scattering as well the nuclear absorption and reemission also called non-elastic scattering, or resonant absorption.

The quantum absorption, often called resonant absorption is based on the nuclear quantum resonance mechanism that is exciting the inner energy levels and excites the absorption element that further decays emitting the energy in various, specific forms, becoming a secondary radiation source.

The curve 110 shows the desired attenuation characteristic mainly based on high albedo, impossible to rich in the classical cases for X, gamma rays and neutrons due to their particularities of the interaction with matter. The multilayer shielding 103 made from individual material layers “i” 109 is showing the actual approach in radiation shielding, that is presenting as disadvantage low absorption factor requiring important thickness and weight.

FIG. 2—Shows the radiation degradation and absorption mechanism used in the actual best radiation shielding. The shielding 200 has a structure arbitrarily taken for exemplification purposes. It is made from an inner layer of iron “Fe” 201, shielded by a layer of silver “Ag” 202 that is shielded at exterior by a layer of thorium 203. As the chart 206 shows thorium having the biggest electronic density and mass density exhibits the biggest absorption coefficient for the radiation 204 generated by a radioactive source 205.

If the radiation energy is greater than 1.022 MeV the interaction process is dominated by the pair generation as shown in the plot 206 that has a relative vertical scale. The pair electron-positron shares the difference of energy as kinetic energy. Both are stopping in the shielding matter by generating showers of knock-on electrons that generates a lot of X rays behind them. When the positron energy becomes small enough it annihilates with a lattice electron reemitting the mass energy of 1022 KeV plus a share of the electron chemical bounding energy by two photons of a little bit more than 511 KeV.

These photons shut at near 180 deg. Represents a new gamma rays source localized somewhere in the Thorium 203 bulk. Another effect according to the plot 206 is the Compton effect. This effect is based on the collision between a photon with an electron, that generates a recoiled electron and a lower energy photon. The recoiled electron is stopped in the lattice generating showers of knock-on electrons with associated X rays, while the lower energy photon in similar with a new source of radiation appeared somewhere inside the shielding, with some angular distribution, given by the Compton effect particularities.

Up to now from a mono-energetic radiation source we obtained an associated large energy spectrum of lower energy radiation, but mainly conserving the initial energy. At lower energy the materials start to exhibit different absorption curves while at higher energies the density was what made the differences in absorption coefficient.

The reasons for this energy degrading material combination is that Thorium 203 with high density high stopping power to stop down most of the initial beam 204 energy producing its own high energy X rays, Compton and annihilation rays. These Thorium secondary generated energies are stopped down in silver 202 with at its turn emits more moderated energies that are dumped in Iron 201. The iron still emits 5.6 KeV as K-alpha specific X ray higher energy and a bunch of specific L, M lines. Aluminum—plastic linear may take out these lines leaving lines only lower than 1 KeV and a bunch of the entire attenuated spectrum. This kind of shielding drives to centimeters of material thickness and specific weight in tones.

FIG. 3—Shows the procedure of enhancing the attenuation coefficient by using a multi-layer decreasing energy resonant absorption attenuation geometry as an embodiment of the present invention. As we observed from the FIG. 2 the attenuation coefficient of materials over 500 keV is practically the same and only the density makes a difference. Density means weight and this turns into excessive weight that impairing the applications. For neutrons the problem is even more difficult, requiring several feet of absorbent materials around.

Keeping in mind the Moessbauer effect and the most used elements there is possible that under the thorium layer from FIG. 2203 to introduce a cascade of Mossbauer elements within mm thick plurality of layers. These elements will enhance the absorption cross-section by the addition of the nuclear resonance that has the final effect the increase in scattering because each absorption is followed by a reemission. In FIG. 3 the entire shield 300 is made from nuclear resonant layers arranged in the order of increasing the nuclear resonant energy towards the radioactive source 303 that produces the irradiation beam 302. The line 304 shows the assignment of the nuclear resonance in the plot 305 to the shield layer 301.

The comb looking nuclear resonances are coming to enhance the absorption cross-section of the multi-material shielding 300, finally reducing its thickness and weight.

The theoretical predictions show a mass reduction of more than 50% from the shielding 200 to 300, but that is not enough for most of the applications. In conclusion, by introducing centers of absorption and reemission of the radiation more than 50% of the incident radiation is backscattered and more than 80% or the radiation power is taken by the shield.

FIG. 4—Shows a main embodiment of the invention represented by the radiation gyration schematics by bended micro wave-guides and nano-fibers. The main driving idea is the concept of radiation channeling in crystals. This concept is proven and in current use for charged particles and neutrons. More using elastic crystals there is possible to easy bend the beams of particles and neutrons similar to light in the optic-fibers,

The development of nano-technologies offered the possibilities to push the wave frequencies even higher.

The radiation shielding is efficient when it denies the radiation access without being damaged in time by radiation-combined effects of power deposition. The shield 400 is made by a few hundreds nm thick channeling layer 400 separated by the interface 406 from a highly absorbent layer 402 stick by the interface 405 from the backing layer 403.

The incident radiation 407 is hitting the layer 401 in the input resonators of the nano-channels 404 that drives the radiation coming at various angles and drives it our of the structure 408 bending it at various angles between 90-180 deg.

The structure is not interfering with the radiation coming from the opposite direction 409.

The intermediary layer 402 separated by the interfaces 405 and 406 is used to apply electric current in order to switch or enhance the reflection properties of the structure, making a control.

FIG. 5—Shows a main embodiment of the invention showing the way a bended molecular wave-guide is made by using multi-layered clustered material. The high reflection material is made of several layers of molecular clusters. The input layer 500 is creating a rarefied electronic structure based on fulerenes or metallic spheres, able to create a resonance cavity to trap radiation inside, in the wave guide made by the molecular orbital 505 The incident wave 508 having the Poynting vector 509 towards the material is reaching a input structure 505, 507 that guides it inside on a resonant path 506. The changes of the molecular distribution from the material 500 to 501 and 502 makes the molecular wave-guide turns, driving the wave back outside by slight interaction with electronic charges 514, and being resonantly trapped into the middle of the wave guide isopotential electronic orbital surfaces 504.

The material 501 is implanted over the interface 500-502 modifying the cluster end in order to produce the wave-guide bending driving the wave inside 515 towards outside 511 traveling in opposite direction 510. The material 502 is deposited on a structural resistance material 503 that may be a polymer, fabric or metal-ceramic sheet.

The total depth of the channels remains small in the domain of 50 nm to several hundred nanometers making that the total impulse transfer due to radiation direction change to be taken by several thousands atomic structures the total energy taken from the radiation being small.

The slight interaction with the electronic structures and hard interaction with the nuclear structures keeps the wave on track changing the direction in small steps. The generation along the channel of orbital magnetic moments is welcomed for neutrons gyration creating a focusing defocusing molecular structure similar to particle accelerators. The resonance between neutron spin turning and the magnetic orbital moment alternating is generating the turning force. For practical reasons a 90 deg. Gyration seems enough for most of the shielding purposes.

For nuclear reaction control purposes up to 180 deg. Gyration angle seems appropriate to keep the radiation in a specific location.

FIG. 6—shows another practical approach of the radiation funneling mechanism by channeling into molecular wave-guides and turning it a little bit. The higher input acceptance angle versus unidirectional escape angle from the channel will modify the initial radiation admittance.

The radiation 605 having a variable energy enters in the reflective solid 600 at a certain angle acceptable distribution 607, accepted for channeling in the first layer 601, that turns it and deliver on a bended angle, suitable for the next layer 602. The incident radiation coming in the 602 layer acceptable angle did not interact by channeling with the upper layer 601 and it is added at the 602-layer entry level with the 601-output radiation.

The second layer 602 output is cumulating with the direct radiation coming up to the angle limit 608 and added to the previous output. By this way the radiation incident on the material's surface between angles 606 and 608 forming the angular acceptance 609 is delivered inside the narrow exit angle 605. The material may be continued with several other layers in the direction 604 such as a 2*Pi incidence angle to be diverted in a single direction.

FIG. 7—is shoving another embodiment of the invention that allows the X gamma and neutrons radiation switch from a direction to another by using a combination of fero-electric and piezo-electric clustered materials. This is important because it introduces the capability of electronic control over the direction the radiation is driven. The application of the voltage on the active layer modifies the structure and orientation of the molecular wave-guides due to electrical anisotropy of the piezo and ferro electric clusters. The simplest device is a lamellar bimaterial with the piezo-electric material being deposited as a layer on the channeling material shrinking or expanding according to the control voltage.

The device in FIG. 7 performs inner intermolecular changes at the cluster level driven by the external voltage. The nano-material is formed from the substrate 700 and the active layers 701 and 702. When the voltage is applied in one direction 705 in the adaptor module 703 the incident radiation 704 is deflected in the direction 706, shown in FIG. 7A. When the applied voltage is modified as 707 the incident radiation will be deflected in direction 708 as showed in FIG. 7B.

The advantage is that the radiation may be controllable driven making a radiation electric shutter.

FIG. 8—shows a main embodiment of the present invention called the “miu” radiation switch with digital control that is mainly a radiation gyrator, based on molecular wave-guides.

The material is in a planar micrometric construction having conductive layers 816 usable to apply the voltage 814 to control the inner channel gate mechanism. The input layer 800 is creating a rarefied electronic structure based on fulerenes or metallic spheres, able to create a resonance cavity to trap radiation inside, in the wave guide made by the molecular orbital 805 The incident wave 808 having the Poynting vector 809 towards the material is reaching a input structure 805, 800 that guides it inside on a resonant path 806. The changes of the molecular distribution from the material 800 to 801 and 802 makes the molecular wave-guide turn driving the wave back outside by slight interaction with electronic charges, and being resonantly trapped into the middle of the wave guide isopotential electronic orbital surfaces 804.

The material 801 is implanted over the interface 800-802 modifying the cluster end in order to produce the wave-guide bending driving the wave inside 815 towards outside 811 traveling in opposite direction 810. The material 802 is deposited on a structural resistance material 803 that may be a polymer, fabric or metal-ceramic sheet.

For nuclear reaction control purposes up to 180 deg. Gyration angle seems appropriate to keep the radiation in a specific location. The application of the voltage over the piezo-structure or ferroelectrics enhanced structured by nano-engineered makes the switch of the channels from turning around 806 to direct transfer 817 allowing the radiation to pass through without attenuation. The control voltage 814 may be applied in digital or analogical manner.

FIG. 9—shows a monolayer “miu” switch schematics with emphasis on operation mode. The material is at the minimal approximation tri-layered. The intermediary layer 902 caring the switch function 905, 915 is separated from the input layer 901 by a conductive interface 906 applying the voltage between 901 and 902 relative to the backing layer 903 grounded by the plot 914. The voltage applied on 902 by the plot 912 induced a displacement in the structure 905, 915 such all the parallel channels initially opened to gyration 909 are moving narrowing the gyration channel but opening the direct pass channel 910. Such as the radiation, gamma, neutron, X coming from 907 direction entering the admittance resonant chamber 907 is voltage 906,912, 914 voltage switched from complete gyration to 908 direction exiting on 904 exit chamber, to the transmission channel 910 exiting on 911 direction forward. This represents the development of a voltage controlled variable albedo shielding reflector.

FIG. 10—shows the application of the voltage-controlled reflectors a embodiment of the present invention in the nuclear reactor control by variable transmission “miu” switch shielding application. This is an important stage of the invention as allows the drastic reduction of the shielding dimensions and mass.

The nuclear reactor structure 1008 operating in direct conversion mode delivering directly the electric power at the plots 1009, 1010 or thermal conductivity heat extraction for which the plots 1009 and 1010 represents the cooling agent exit and input in the reactor critical volume. The criticality is controlled by the transmission of the nano-shielding such as to maintain the required power level. When the power have to be increased the transmission through the shield 1000 is increased. The released neutrons are used for the fuel breeding 1001 or fission products 1006 burning purposes. There are numerous plots to control the sector shielding as 1011 for the outer layer, while 1012 controls the top shielding. The escape neutrons are hitting the shielding 1000 in the point 1003 and dependent of the applied voltage applied on 1011 they can reflect back in the reactor or be released interacting with the breeding fuel being absorbed in the point 1005 or scattered hitting further the nuclear reactor external shield 1004 reflecting back. Here they may be funneled placing them tangent to breeding structure or being allowed on a radial path inside the nuclear reactor. In the upper side the escaped neutrons may cross through the shielding in the point 1014 depending on the voltage preset applied at plots 1012 and ent transmuting a fission product 1006 in the point 1013. The entire structure is introduced in an external case 1007 with multiple functional roles.

This represents an important advancement as makes the nuclear power accessible on vehicles, few MWDay structures being possible of being produced in cubes of 2 feet lateral powering a car, house, residence for several years continuous driving.

FIG. 11—Shows another application, the use of a radiation funneling shielding to shield plasma focused fission device being an embodiment of the present invention. Shows an application related to colider fusion device based on two opposite direction beams, for which the center of mass of the colliding particles is in repose overlapping the center of the harvesting geometry.

The colider may be also achieved with a fixed perpendicular thin target and a down flow harvesting structure. In the drawing the role of the nano-shield 1102 is to funnel the secondary radiation 1104 coming from the harvesting element 1103 such as to maximize its path in the absorbing element 1105 until it hits the outer nano-shielding 1101 with reflects it back tangentially 1106. The fusion assembly 1100 may have the fusion reactions of Boron 1108 proton 1107 giving a Helium particle and a 8Be that instantly decays 1109 in two Helium particles, or Lithium 1111 deuteron 1112 or proton giving two Helium 1110 particles. The Helium particles carrying the fusion energy as kinetic energy interacts with the direct conversion structure 1103 that takes their energy and transforms it into electricity.

FIG. 12—shows another application as embodiment of the present invention in the application of the nano-layered funneling shield as a space-shuttle radiation-shielding device for charged particles and X, gamma rays. In this case the outer frame structure 1200 that protects the payload inside is shielded laterally by nano-foils 1201. This foil is funneling the radiation 1204 by controlled tunneling reflection 1203 to the harvesting elements 1202. For charged particles 1205 specialized inertial spinning magnetic coils 1206 are driving the charged particles to specialize or universal harvesting elements 1202. In this way a cosmic ray protection similar to that of the earth may be achieved.

FIG. 13—shows another embodiment of the present invention that is a multi-focusing multi-layer device operating as gamma, X, n, charged particle imager. Various layers 1301 having narrow admittance angle and narrow directive output create the material 1300. A radiation wave coming from the direction 1392 is transmitted on the direction 1303 towards a point in space 1304 where a detector is placed. The same happens to radiation 1305, transmitted on the direction set 1306 towards the point 1307 with the appropriate detector. The radiation 1308 is also transmitted on the directions set 1309 towards the point 1310 with the appropriate detector. The radiations 1302, 1305 and 1308 may be different and come under the same incidence angle, or may be the same class, and the detectors may be different. The selectivity choices are multiple and are construction and materials type particularizations.

FIG. 14 shows the space-imaging device for terrestrial and outer space applications. It is mainly a 2-3 PI imaging device, with angular selectivity. A plurality of such devices may generate a 3D image in spherical coordinates. The sensitive cylinder or prism 1400 contains a multitude of planar or bended layers as shown in FIG. 13 concentrating the radiation to imaging points set on the hyper-surface 1401, equipped with the appropriate transducers, with some symmetry and access shape 1402. A ray 1404 is directed inside the set angles 1405 to a specific concentrator/imaging point. The same happens with the ray 1406 poised on the direction set 1407 towards the detector 1403. The shape, detector types, radiation selectivity criteria are buildup elements and may vary in a wide margin.

FIG. 15—shows how the adapted nano-tube wave-guide works as an example for the buildup of the molecular wave-guides. The material 1500 is made of a plurality of layers from which the figure shows only three. The admittance-exit layer 1501, is followed by the channeling-in nano-structure layer 1502, placed on a substrate layer 1503. A control voltage may be applied between the extreme layers or control layers 1501 and 1503, having as effect the displacement of the atom 1507 that interferences with the admittance path, and resonator trapping device 1506 made from a nano-cluster of various materials and various geometries. The incident radiation coming from the direction 1511 or 1512 is trapped in the structure 1506 and injected in the nano-wave-guide 1508.

The radiation interacts slightly with the nuclei in the nano-tube that are seen at the grazing angle, being driven with almost no energy exchange towards the exit device 1504. This device matches the radiation determining the direction 1517 and the cardioid's 1518 shape or exit angular distribution. The admittance cardioids 1510 are determined by the input adapting structure 1506 that makes the oscillation inside the nano-cluster 1514 adapted to be injected 1515 in the molecular drive.

After channeling inside the structure 1505 the wave gets into the exit adapter 1504 having a matching 1516 oscillation before departure. It is possible that passing through these structure the shape of the photons to be modified as well the energy. The selectivity between the rays X, X′ and X″ is a constructive details. The structure is reversible if the input and output matching structures are properly arranged.

FIG. 16 shows the complete shielding structure section 1600. This is achieved from a plurality of layers with various functions in radiation 1607 propagating towards the shield 1608 denial or control. The first layer 1601 is design of harvesting the energy from low penetrating radiation like charged particles up to MeV domain and electromagnetic field with energy less than few eV delivering it at the electric plots 1611. It also acts as a protection for the next layer depleting the radiation 1610 of its low penetration components and may be replaced by an anti-chemical protective layer.

The next layer 1602 is made of a plurality of layers containing nano-tubes or organized nano-clusters 1621, 1622 adjusted for various particles and various angles controlled by the voltage applied to the plots 1623. In this layer the radiation 1610 is back-reflected 1624 by gyrating inside the molecular wave-guides leaving a small amount of being transmitted 1625.

The layer 1603 has mainly separation and resistance functions. The layer 1604 is based on atomic absorption enhanced by nuclear resonance cascade. The absorptive layers 1641, 1642 have various nano-micro layers of various isotopic enriched materials eliminating resonant bands from the gamma, n radiation spectrum. The layer 1606 is the last resort of protection being based on mass absorption in degradation lattice, being mainly a usual shielding. The remnant radiation 1660 is supposed to be very low, with orders of magnitude. The dashed line 1605 is a symmetry line for the case when the shielding arrangement is bi-directional. The symmetry line may be also build on the 1603 layer for nuclear radiation control applications.

FIG. 17 shows another embodiment of the invention related to the atomic level radiation channeling through an atomic structure presented in a window 1700. The picture shows several atoms 1701 connected through chemical bounds at the 2p 1714 orbital level—like Carbon—but that is not an issue, is just for simplicity of the example. The lattice, a cluster, nano-tube has a cell dimension. The electric potential curve 1702 starts at the nucleus 1701 where it has a high value decreasing fast with the distance, and being partially shielded by the electrons placed on atomic orbital 1s, and 2s 1721, 2p 1711 and 2p-bound 1714.

The atomic channel given by the atoms alignment 1704 is bended left by a gap 1705 determining the radius of curvature of the structure by using the

equation:

$α = \frac{Δ y}{A} = \frac{A}{R} \Rightarrow R = \frac{A^{2}}{Δ y} -> 2$

If keeping a smaller than 2 degrees for an interatomic distance of 3 Angstroms=A, (sp²bound in CNT is 1.41 A) we get a radius R=20 nm. Of course this looks very small but is the lower limit a molecular wave-guide effect may occur. In reality the radiation wave 1703 has a finite length of several [nm] up to hundreds of [nm], depending on the production source, with a E;B profile wearing the signature of the primary source and the environment it passed through. In our example it has also a width and an envelope 1732 with the Poynting vector Y 1731 centered in the channel. The image resembles a ship in a strait. In normal environments between 250 and 400 Kelvin degrees the atoms have molecular vibrations at THz frequencies. Thou the atoms have not fixed locations as figured by the alignment axes 1704 but likelihood places figured by the rectangles 1706 where in plain they describe a combined oscillatory movement similar to Lisajoux trajectories, under the action of the figured in plane oscillations 1717 on z axis, 1718 on y axes and 1712 on xz. In reality these movements have to be treated in volume and a plurality of specific eigen-frequency in THz domain, specific to all molecular vibrations. These movements may make the wave-guide impractical above a certain temperature, because the atoms may interpose with the wave driving to a nuclear collision effect known under the name of Doppler broadening.

This effect generates Compton recoil electrons 1708 that stops far in the lattice by generating a cascade 1709 accompanied by X rays and energy and direction modification going astray.

This imposes the following requirements:

- The nanowire to be pretty straight and long free of sudden curls, while the gap on the rotational axis to be a rational number so during a twist around its symmetry axis the molecules to cover all the space.
- The nano-structure has to be as compact as possible and with high Z number so the fields constrain to be big enough to bend the radiation wavelet and keep on the channel.
- There is possible to vary the isotope in such a manner to create a funnel and control the exit from the channel.
- The chemical stability and the molecular strength have to be high so that the amplitude of the molecular vibration to be small enough to require no cryogenics.

The development of organized structures have also to have a high fill factor, that possible may not be higher than 10% so a 20 layers structure might be necessary.

FIG. 18—shows another embodiment according to the invention said radiation selective extractor/gyrator 1800.

A beam 1802 of composed radiation reaching the target 1801 comes, and is separated on types and extracted from the hot area by specialized guiding tubes 1804, 1808, driving it to receivers.

The radiation may be a mixture of n, gamma becoming p, e, and gamma for travel times greater than ½ hour due to n disintegration. The n emitter modulation carries a fake signal while gamma caries the true signal. Their overlap on target makes the decoding hard due to physical properties of the signal that have to be extracted from the high-energy radiation background.

This kind of communicator is also usable in high radiation environment where the noise 1805 distinctly extracted may be separated from the real information-carrying signal 1807. The system is transparent to the radiation not matching the extraction conditions 1806.

The nano-structured entry interface 1801 takes inside all the radiation that is focused 1803 to the input filters of the specialized extraction guides. This device may use the signal decoders for imaging and communication purposes. The radiation modulation might be done with the electro-sensitive radiation transport device shown in FIG. 9.

In FIG. 19 as a whole body protective coat 1900, formed by the upper body coat 1907 and pans 1908 with protective shoes or boots 1909.

The coat 1901, 1907 may include helmet or hood 1903 and a backpack 1902 for survival and instrumentation. The face protection may have a face protection shield 1904 that may be transparent for eyes or completely opaque equipped with complex orientation system 1905, giving the images of the terrain in various bands and radiation. The gloves 1906 may have various degrees of flexibility and protection. The advantage of this suit is that it may exhibit attenuation coefficients up to ppm level and weight by 100 times lower than it would be fabricated by the mass attenuation materials.

Some flexibility degree will be possible in the suit. The suit may be used in various configurations and circumstances for individual protection as military suit, security first intervention, hazmat environments, outer space for astronaut suit or for outposts shielding, for shelter in place, portable emergency vehicles, etc.

FIG. 20 shows an accomplishment of these active shields 2000 in lightening and miniaturizing the nuclear power sources as fission, fusion and hybrids. The entire assembly is contained into a technologic case that has mechanical resistance purposes and shielding purposes as electric, radiation, etc, containing pressure and temperature. The total reflection external shield 2002 is reflecting all the particles coming from the hot area towards inside, keeping the radiation together I a smaller confinement zone. Immediately near the absorber is placed a multipurpose cooled absorber material making a sealed structure able to confine pressure and temperature, up to a limit where it has a controlled release. A direct conversion layer and gamma absorber material form the absorber. It also exhibits chemical stabilization materials. The breeding control adjustable reflection shield 2004 is driving the neutrons to the absorption layer mainly having the function of breeding and transmutation, when it is electrically polarized and transparent to the total reflection, reflecting them inside for power production. Breeding nano-material 2005 contains ²³²Th, ²³⁸U, or may contain other materials for transmutation and radioisotopes production. To keep a constant reactivity in this area the transmutation products will be removed from the production area in a storage cooling compartment. Power control adjustable reflection shield 2006 is made form the active material, whose transmittance and reflection also called albedo is done by using a control system for criticality 2007, that together with the Breeding control system 2008 assure the neutron 2009 flux management establishing their trajectories 2010 and range. All the functions are automatically controlled in order to balance the power output 2011 produced with the power demand of the system this part is integrated.

FIG. 21 represents an example of mobile portable nuclear power source 2101, based on reflective Nano-Shielding 2102 that may drive to super-critical nuclear sources, as an example 239 Pu based reactor reaching the criticality with less than 50 g of fissile material. The produced power is transmitted to wheels electric motors 2103 making part of the integrated vehicle system 2100.

Other examples as trains, ships, planes, super-planes space shuttles and underwater devices are also possible.

BRIEF DESCRIPTIONS OF INVENTION

The invention refers to a new type of active nano-structured material to be used for X, gamma and neutrons shielding and control. The main idea behind the patent comes from the actual super-mirror used in synchrotrons X ray focusing and cold neutron transport at spallation sources. The other idea used in the patent approach was the fact that the interaction between high-energy radiation and materials is very weak except for nuclear resonances. Such resonant materials may have small thickness but they may generate high absorption rates.

The equation 1 is characterizing the process:

I(E_j)=I₀(E_j)exp(μ_ixⁱ+δ_jⁱμ^jx^j) Eq.1

where I is the intensity in a point x on the axis for an energy belonging to the energy group j.

The group width is set to be equal with the resonance's effective width (something like nσ where n is a reasonable value usually smaller than 3). μ is the liniar absorption coefficient absorbing the value

$\frac{μ}{ρ} ρ_{i}$

where μ is the material specific absorption density while ρ is the material mass density and ρ_iis the specific material density spanning the length x_i.

Using this concept there is possible to make arrangements of various materials resonantly absorbing the incident radiation, activating the internal nuclear channel and dezexciting by following the nuclear branching paths. There are very few cases when the excited nucleus is emitting a higher energy than it absorbed, therefore the new material becomes a new source of radiation in that bandwidth backscattering theoretically 50% of the primary radiation. If consider two repetitive layers separated by a distance they theoretically cut down 75% of the radiation by backscattering. The disadvantage of these materials is that the resonance band is very narrow, so a sandwich is required to cut down most of the energetic groups, but the nature did not provided so many stable isotopes as we may need to make resonant shielding. Radiation buildup is also important but is considered a secondary effect for this approach.

The usage of the first concept about radiation reflection at grazing angles together with the fact that the radiation interaction with the surface is local at few tens of atoms driven the conclusion that a nano-tube slightly bending, see FIG. 17 may offer the same conditions, and more it may contain the radiation and slightly center in the tube hole. The nano wires are naturally bending and so the radiation. One of the problems to be solved is the small admittance for the radiation inside the molecular wave-guides that is solved by growing fulerene like structures that will divert the radiation inside sa described in FIG. 15.

FIG. 1 describes the 3 types of shielding, from which the patent brings as new the nuclear resonance enhanced absorption and the molecular wave-guides radiation gyration.

If the resonance enhanced radiation absorption and reemission described by FIG. 3 may brining a passive shield with maximum 1-2 orders of magnitude thinner than the classical mass absorption actual shielding described generically in FIG. 2, the radiation gyration by molecular wave-guides described by FIG. 4 opens new perspectives.

As FIG. 5 shows there is necessary to build organized nano-structures, that to create the so-called molecular structures. These structures may be build in many ways, but for simplicity one way to build is by starting from a Si, Diamond substrate, building by beam-annealed Au self organized nano-clusters, and building a layer of carbon nano-tubes, slowly bended in about 500 nm to 1 micron. Over this layer a new conductive micro layer is deposited as TiO and W, or WC follows by pulsed laser deposition than by Au, Ag deposition. This substrate will create the germination for the new set of C nano-tubes deposited by CVD, slightly tilted than the first.

By this way a plurality of substrates may be build. Another modality of building the organized structure is to perform a combined CVD and Laser Pulsed Deposition, assisted by an interfered ion bean on a 10 nm pattern to create the thermal spikes to induce the nucleation of the nano-clusters and separation of the depositions. In this structure the organized layers of nano-clusters will float in an insertion material also partially crystallized. The insertion of a piezo material as BaTiO4 by LPD or a ferro-electric material as TGS brings the possibility of the electric control of the radiation direction by obtaining the molecular wave-guide switches.

As already resulted from FIG. 5 and in the molecular switch version presented in FIG. 8 there is difficult to achieve this effect by using few atoms. A collective action with the participation of few thousands atoms is needed to completely gyrate MeV n or gamma rays as detailed in FIG. 17.

In the case og the gyration by 180° of the radiation of few MeV on 1000 atoms, an energy exchange of several tens of eV will be transferred to lattice due to impulse transfer. This is enough to warm-up that channel and the structure to require cooling.

The main formula is:

$\begin{matrix} p = 2 \frac{E}{c} = nMv -> v = \frac{2 E}{cnM} \Rightarrow Δ E = \frac{2 E^{2}}{c^{2} nM} = {nk}_{B} T & (3) \end{matrix}$

that in the case of 1 MeV radiation turned by 1000 atoms gives about 2.5 eV that drives to a 3° K temperature increase per particle.

This is not so bad showing that high doses may be handled by this mechanism without significant radiation damage effects. To calculate the radiation damage the isotopic specific interaction cross-sections have to be considered. Without doing this we observe that in the radiation admission interface small cross-section materials have to be used to channel the radiation. The particularity of the channeling process exploited in the present invention consists in the fact that the radiation quanta interacts mainly with the collective atomic electric field and not directly with the nuclei, making the interactions small.

The application of the material in communication in FIG. 18 uses the selectivity and electric control that makes possible the modulation as emitter and the direct conversion systems with fast response detection and demodulation. The high sensitivity makes possible the data and signal transmission through shielding materials and high absorbers.

The usage of these materials inside nuclear reactors is making possible the replacement of the mechanical control rods by electric controlled albedo materials, increasing the n usage and making an optimal management of breeding, transmutation and partitioning. The waste and contamination will be drastically removed The drastically change in the nuclear reactor structure. Same structure might be used to fusion structures, accelerator driven structures and hybrid structures.

Nano-structured nuclear radiation shielding

Information

Publication Number

Date Filed

Date Published

Inventors

CPC

US Classifications

International Classifications

Abstract

Description

Claims

CROSS REFERENCE TO RELATED APPLICATIONS

Provisional Applications (1)