The invention consists in structuring scintillation radiation detectors as Photonic Bandgap Crystals or 3D layers of thin filaments, thus enabling extremely high spatial resolutions and achieving virtual voxellation of the radiation detector without physical separating walls. The ability to precisel
The invention consists in structuring scintillation radiation detectors as Photonic Bandgap Crystals or 3D layers of thin filaments, thus enabling extremely high spatial resolutions and achieving virtual voxellation of the radiation detector without physical separating walls. The ability to precisely measure the recoil electron track in a Compton camera enables to assess the directions of the gamma rays hitting the detector and consequently dispensing with collimators that strongly reduce the intensity of radiation detected by gamma cameras. The invention enables great enhancements of the capabilities of gamma cameras, SPECT, PET, CT and DR machines as well as their use in Homeland Security applications. Methods of fabrication of such radiation detectors are described.
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I claim: 1. A radiation imaging system consisting of one of group comprising a Compton camera, a Gamma Camera, a SPECT, a PET, a CT and a Digital Radiography system wherein said radiation imaging system includes radiation detectors for detecting ionizing radiation wherein, said radiation detectors
I claim: 1. A radiation imaging system consisting of one of group comprising a Compton camera, a Gamma Camera, a SPECT, a PET, a CT and a Digital Radiography system wherein said radiation imaging system includes radiation detectors for detecting ionizing radiation wherein, said radiation detectors comprise a plurality of adjacent non-touching Photonic Bandgap Crystal lattices, wherein, each said lattice consists of matrix of first material containing non-touching vertical tubular elements of a second material wherein said second material has different refractive index than the first material and wherein, said tubular elements are organized in periodically recurring geometrical structures formed by no more than 5 tubular elements, wherein said periodicity is across the lateral plane perpendicular to the direction of the tubular elements of the lattice, wherein the first and second materials are selected from a group comprising, scintillator materials and non-scintillating materials transparent to scintillation wavelengths and having a refractive index smaller than 1.2, and wherein, a the distance between the non-touching vertical tubular elements, and b the distance between the non-touching lattices and c the diameters of the vertical tubular elements are less than the wavelengths of the scintillation light, wherein said a distances between the non-touching vertical tubular elements, and b diameters of the vertical tubular elements and c distances between the non-touching lattices and d the refractive index contrast between the first material and the second material are selected in a manner that maximizes the amount of scintillation light is inhibited to propagate laterally across the periodical groups of tubular elements of the lattice and wherein at least one of the edges of the lattices normal to the direction of the tubular elements is covered by a multiplicity of photo-electric sensors sensitive to the wavelengths of the scintillator and wherein the edges of the lattices not covered by photo-sensors are coated with materials reflective to the wavelength of the scintillator and wherein the position of a scintillation along the direction normal to lateral periodicity plane, where an ionizing radiation caused said scintillation, is determined by the shape of the distribution of the intensity of scintillation light, exiting the non-coated edges of the lattices from the region around the tubular scintillator where the ionizing radiation caused said scintillation, wherein said photo-electric sensors connect to electronic circuits that measure the intensity, timing and lateral distribution of electrical signals generated by said sensors. 2. A radiation imaging system as in claim 1 wherein the periodically recurring geometrical structures of tubular elements are selected from a group comprising triangular and open hexagonal geometries and wherein the periodically recurring groups of tubular elements are further grouped in sets of groups consisting of less than 25 groups of tubular elements wherein the diameters of said tubular elements and the distances between them in a set of groups change periodically wherein said changes further maximize the scintillation light that propagates along the direction of the tubular elements. 3. A radiation imaging system as in claim 1 wherein the periodically recurring tubular elements consist of holes in a scintillator matrix filled with air wherein said tubular elements are arranged as triangular lattice having a two dimensional periodically and wherein said tubular elements have diameters larger than 80% of the distance between them. 4. A radiation detector as in claim 1 wherein the tubular elements consist of scintillators in a matrix filled with one of a group comprising aerogels, xerogels and air, wherein said scintillators are coated with materials of higher refractive index. 5. A radiation detector as in claim 1 wherein light of lower wavelength is pumped onto the tubular scintillators thus amplifying the scintillator light by stimulated emission. 6. A radiation detector as in claim 1 where in the tubular scintillators are coupled to light guides of the same diameter wherein said light guides are doped with the same activator material as the scintillator, and wherein light of lower wavelength pumped onto said light guides, amplifies the scintillator light passing through said light guides by stimulated emission. 7. A radiation imaging system as in claim 1 wherein the sequential adjacent lattices of the radiation detectors, have mutually orthogonal planes of periodicity. 8. A radiation imaging system as in claim 1 wherein the position of a scintillation along a tubular scintillator where an ionizing radiation caused scintillation, is determined by comparison between the respective lateral distributions of the intensity of scintillation light exiting from the tubular scintillators of two adjacent mutually orthogonal lattices, in proximity to said tubular scintillator. 9. A Compton camera radiation imaging system as in claim 1 wherein the position of a source of gamma rays in 3D is determined by determining the coordinates of the beginning of the tracks caused by two ionizing events occurring in rapid sequence in one or more different radiation detectors by measuring the coordinates of the beginning of the tracks caused by two ionizing events occurring in rapid sequence in one or more different radiation detectors by measuring the coordinates of each scintillation even, by comparing the respective lateral distributions of the intensities of scintillation light exiting from the tubular scintillators of two adjacent and mutually orthogonal lattices, in proximity to the tubular scintillator where the ionizing radiation caused a scintillation, and by finding the best fit of said measured coordinates to a straight line, derived by minimizing the aggregate distance of the measured coordinates of the scintillations in a multiplicity of tubular scintillators in close proximity to such line and wherein the beginning of a track and its direction are determined to be the beginning and the direction of said best fitting straight line respectively and wherein the energy of an ionizing event is obtained by adding the signals exiting all the tubular elements in close proximity and wherein the direction of a Compton scattered gamma ray is found from the energies, positions and directions of the tracks of sequential events in coincidence wherein the direction of the source of gamma rays is determined by selecting events resulting from scattering at angles where the sum, of the variance of the direction of the recoil electrons and the correlated variance of the energy of the scattered gamma ray, is minimized, wherein said angle is a function of the energy of the primary gamma ray wherein the position in 3D of a gamma ray emitting source is determined by the intersection of the directions of the primary gamma rays interacting with the radiation detectors. 10. A SPECT radiation imaging system as in claim 9 comprising two Compton cameras wherein said Compton cameras are positioned to view the source of radiation at 90째 angle between them wherein the location of the gamma emitting source is determined by the intersection of the directions of the primary gamma rays detected by any of the two Compton Cameras when stationary, and wherein said pair of Compton cameras can rotate on a circumference around the source of the gamma emitting source. 11. A PET radiation imaging system as in claim 9 consisting of a multiplicity of Compton cameras wherein said multiple Compton cameras cover only a 180째 sector in face of a positron source wherein said Compton cameras establish the direction of the positron source by determining the direction of a single 511 keV gamma ray and wherein said Compton cameras can establish the location of radio-pharmaceuticals emitting gamma rays in a time sequence by determining the direction of gamma rays of the desired energy detected in a predetermined time sequence. 12. A radiation imaging system consisting of one of a group comprising a Compton camera, a Gamma Camera, a SPECT, a PET, a CT and Digital Radiography wherein said radiation imaging system includes radiation detectors for detecting ionizing radiation wherein, said radiation detectors comprise a multiplicity of adjacent layers of tubular scintillator elements wherein each said layer consists of straight tubular scintillator elements of a diameter of less than 100 microns wherein said tubular scintillator elements are laid side by side in a matrix having a refraction index of less than 1.2 wherein the distance between adjacent tubular scintillator elements is more than the wavelength of the scintillator wherein the space between adjacent tubular scintillator elements is filled with a material having a refraction index of less than 1.2 wherein at least one of the edges of the layer normal to the direction of the tubular scintillator elements is covered by a multiplicity of photo-electric sensors sensitive to the wavelengths of the scintillator and wherein the edges of the layers not covered by photo-sensors are coated with materials reflective to the wavelengths of the scintillator and wherein said photo-electric sensors connect to electronic circuits that measure the intensity, timing and lateral distribution of electrical signals generated by said sensors wherein, the position of a scintillation along a tubular scintillator elements, where an ionizing radiation caused said scintillation, is determined by the shape of the distribution of the intensity of scintillation light, exiting the non-coated edges of the lattices from proximal region around the tubular scintillator element. 13. A radiation imaging system as in claim 12 wherein adjacent layers are mutually orthogonal. 14. a radiation imaging system as in claim 12 wherein said tubular scintillator elements are surrounded with a plurality of transparent material layers that increase the amount of scintillation light propagating along the tubular scintillator element. 15. A radiation imaging system as in claim 12 wherein said tubular scintillator elements are surrounded by several rings of holes in a loosely connected matrix. 16. A method of manufacturing a Photonic Bandgap Crystal Scintillator array of tubular scintillators wherein each tubular scintillator has a diameter of less than 10 micron and spaced at less than 1 micron apart wherein said method comprises the steps of; a creating first mold of holes of a diameter less than 10 micron and distances of less than 1 micron apart, in solid material by one of the processes comprising a1 femtolaser ablating, a2 UV laser irradiating followed by chemical etching, a3 nano-imprinting followed by plasma etching and electroplating wherein said solid material is one of a group comprising scintialltor, a glass, a plastic, a metal, an elastomer, a gel or an aerogel; b creating a second mold of tubular scintillators by one of the processes of b1 extruding a viscous substance through the holes of the first mold and solidifying it by heat of light wherein said substance is one of a group comprising a heat liquefied scintillator, a phot-polymer, a solvent liquefied substance, an epoxy or a sol in the process of being gelated b2 curing tubular scintillators of a photo-polymer with a tubular light beam delimited by the holes of the first mold, while extracting the non-polymerized solution around the polymerized tubular scintillators, while the light polymerization process advances in the photo-polymer along tubular lines b3 depositing vapors of a superheated melt passing through the holes of the first mold and crystallizing on a cooled template of pointed elevations, wherein each such elevation is in front of a hole of a first mold, wherein an electrostatic field is established between the first mold and said template of pointed elevations and wherein the cooled template is slowly retrieved as the tubular crystals height grows; c creating a third mold of holes in matrix by c1 filling the space between the tubular scintillators of the second mold with a substance wherein said substance is one of a group comprising a heat liquefied scintillator, a phot-polymer, a solvent liquefied substance, an elastomer, an epoxy or a sol-gel and c2 solidifying said substance by one of the processes comprising cooling, polymerizing, curing or gelating c3 eliminating the tubular elements within the third mold by heat, chemical etching, stripping or breaking; d filling one of the first, second or third molds with an ultrafine powder of nanosized particles of size less than 100 nm, of a scintillator material tha thas a melting temperature lower than that of the mold; e crystallizing the material within the mold by e1 heating it above the melting temperature of the scintillator and melting it e2 placing around the shorter section of the mold two sets of closely spaced inductor heaters, and IR lasers, wherein the two sets of heaters and IR lasers establish within the melt a gradient of temperature from below the melting temperature to above the melting temperature, within a short distance, e3 advancing the temperature gradient front slowly across the mold by moving the inductive heaters and IR lasers and crystallizing the melt at the lower side of the temperature gradient; f after slowly cooling the crystal to avoid cracks, eliminating the mold by one of the methods consisting of heating, chemical etching, stripping, breaking or shattering by ultrasound irradiation or leaving the aerogel in place to support the structure of columns. 17. A method of manufacturing a Photonic Bandgap Crystal Scintillator array as in claim 16 whereas a first mold is prepared by nano-imprinting a metallic plate followed by plasma etching and electroplating and further extruding a liquefied glass scintillator through the holes of said first mold and solidifying it by heat. 18. A method of manufacturing a Photonic Bandgap Crystal Scintillator array as in claim 17 whereas the extruded substance is photo-polymer including doped p-terphenyl. 19. A method of manufacturing a Photonic Bandgap Crystal Scintillator array as in claim 17 whereas the vapors of a superheated melt of a Lanthanum Chloride Bromide scintillator passing through the holes of the said first mold are deposited on the pointed elevations of the cooled template aided by an electrostatic field between the mold whereas the cooled template is slowly retrieved. 20. A method of manufacturing a Photonic Bandgap Crystal Scintillator array in claim 17 whereas the vapors of a superheated melt of a Yittrium Gadolinium Oxide scintillator passing through the holes of the said first mold are deposited on the pointed elevation sof the cooled template aided by an electrostatic field between the mold. 21. A method of manufacturing a Photonic Bandgap Crystal Scintillator array as in claim 16 comprising the steps of creating a first mold by nano-imprinting a metallic plate followed by plasma etching and electroplating and further creating a second mold by extruding a photo-polymer throught he holes of said first mold and solidifying it by UV light and further creating a third mold by filling the space between the polymerized tubular elements by an aerogel through a sol-gel process and further eliminating the polymerized tubular elements by heat and sintering the aerogel matrix by heating it above 1000째 and further filling the holes of the glassy mold with nano-crystal of Lanthanum Chloride Bromide and melting them at 950째 and crystallizing the scintillator in the holes, and leaving the aerogel matrix in place to support the Lanthanum Chloride Bromide structure of columns.
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