High definition scintillation detector for medicine, homeland security and non-destructive evaluation
A bundle of drawn fibers that have X-ray scintillating unagglommerated nanocrystallite particles in plastic or glass cores of down to 0.1 micron spacing and claddings of X-ray absorbing compounds in the cladding composition. Optional is a cover to the bundle that blocks light from leaving the bundle at the X-ray side while allowing X-rays to pass into the cores. To image the light exiting the fiber bundle at the sub-micron level, light expansion is preferable using either a lens system or a fiber bundle expander.
1. An assembly for converting X-rays to detectable light comprising:
a fiber optic bundle including:
a plurality of fiber cores of unagglomerated, nanocrystallite scintillation particles suspended in a plastic body, said scintillation particles providing scintillation in response to incident X-rays; and
at least one cladding of a non-scintillating material surrounding each of said plurality of fiber cores,
wherein said plurality of fiber cores and the respective cladding collectively form the fiber optic bundle, the fiber optic bundle operative to direct light from X-ray scintillation along the plurality of fiber cores.
2. The assembly according to claim 1 wherein
the cladding is comprised of a material absorptive to X-rays.
3. The assembly of claim 1 wherein said plurality of fiber core are of a material of a first refraction index and the cladding is of a second refraction index.
4. The assembly of claim 3 wherein said first and second refraction indices are selected to confine light from X-ray scintillation to a fiber core in which it originates.
5. The assembly of claim 1 further including:
a multi-sensor detector assembly; and
an imager for imaging light from X-ray scintillation from said fiber optic bundle onto said multi-sensor detector.
6. The assembly of 5 wherein said imager includes a lens.
7. The assembly of claim 5 wherein said plurality of fiber cores have corresponding diameters, and wherein said fiber optic bundle has a core spacing defined by the diameters corresponding to the respective fiber cores.
8. The assembly of claim 1 wherein said fiber optic bundle has a core spacing in the range of 0.1 to 25 microns.
9. The assembly of claim 1 wherein said fiber optic bundle comprises one or more sets of fiber optic bundles formed in one or more bundle drawings.
10. The assembly of claim 1 wherein each of said plurality of fiber cores and the respective cladding is of a cross-sectional shape selected from the group consisting of circular, hexangular, and square.
11. The assembly of claim 1 wherein each of said plurality of fiber cores has a corresponding diameter greater than or equal to 100 nanometers.
12. The assembly of claim 1 further including a cover disposed over said fiber optic bundle that is reflective to light and transmissive to X-rays.
13. An X-ray imaging system, comprising:
an X-ray source;
an object position for subjects to be analyzed by X-ray exposure;
an assembly according to claim 1 positioned to respond to X-rays passing through one of said subjects at said object position to provide light as an output from said fiber optic bundle; and
a light detector for sensing said output and providing an image signal in response thereto.
14. The imaging system of claim 13 further including an imager for providing a visible image in response to said image signal from said light detector.
15. A method of forming the fiber optic bundle of claim 1 comprising the steps of:
drawing two or more sets of fiber optic bundles;
stacking sets of drawn fibers together after drawing each of said two or more sets of fiber optic bundles; and
drawing the stacked sets.
16. The assembly of claim 1 wherein said unagglomerated scintillation particles are comprised of a compound selected from the group consisting of: Lu 2 Si 2 O 2 :Ce, LuAlO 3 :Ce, Lu 2 SiO 2 :Ce, LuPO 4 :Ce, PbWO 4 , GdSiO 2 :Ce, and BiGe 3 O 4 and their plastic scintillating analogues.
17. The assembly of claim 1 , wherein the at least one cladding comprises an optically absorbent layer for absorbing scintillation photons impinging the cladding at angles too large for total internal reflection.