Patent Number: 
Section: claims

1. A system for generating isotopes, comprising:an accelerator;a source of charged particles coupled to the accelerator to inject charged particles into the accelerator;a target positioned in the path of the accelerated charged particles, the target comprising:a first, inner target material comprising a first isotope of molybdenum; anda second, outer target material comprising a second isotope of molybdenum, the second outer target material at least partially surrounding the first, inner target material, the second, outer target material defining a passage for accelerated charged particles to the first, inner target material. 2. The system of claim 1, wherein the first isotope and the second isotope are different isotopes of molybdenum. 3. The system of claim 2, wherein the first, inner target material and the second, outer target material are separated by a gap. 4. The system of claim 1, wherein the first isotope and the second isotope each comprise molybdenum-98. 5. The system of claim 2, wherein the first isotope comprises molybdenum-100 and the second isotope comprises molybdenum-98. 6. The system of claim 1, wherein the target further comprises a layer of hydrogenous material between the first, inner target material and the second, outer target material. 7. The system of claim 1, wherein:the first inner target material comprises a Bremsstrahlung material;the second target material comprises molybdenum 100; andthe target further comprises third target material comprising molybdenum-98 at least partially surrounding the second target material. 8. The system of claim 1, further comprising:a target assembly containing the target;a target chamber containing the target assembly; anda drift tube coupling an output of the accelerator to the target chamber, defining the path from the accelerator to the target. 9. The system of claim 8, further comprising:electromagnetic coils adjacent to the drift tube, to selectively deflect the accelerated charged particle beam onto at least two locations on the target. 10. The system of claim 1, wherein the accelerator is chosen from the group consisting of a cyclotron, a radio frequency quadrupole accelerator, and a linear accelerator. 11. The system of claim 1, further comprising:means for rotating the target. 12. The system of claim 1, wherein the source of charged particles comprises a source of deuterons. 13. The system of claim 12, wherein:the accelerated charged particles comprise accelerated deuterons;the first, inner target material comprises molybdenum-98, wherein bombardment of the first, inner target material by the accelerated deuterons during operation generates molybdenum-99 and metastable technetium-99, and releases neutrons; andthe second, outer target material comprises molybdenum-98, wherein impact of the second, outer target material by the released neutrons generates molybdenum-99 and metastable technetium-99. 14. The system of claim 13, wherein the target further comprises:a layer of hydrogenous material between the first, inner target material and the second, outer target material. 15. The system of claim 14, wherein the target defines a gap region between the first, inner target material and the layer of hydrogenous material. 16. The system of claim 1, wherein the source of charged particles comprises a source of electrons. 17. The system of claim 1, further comprising:an electromagnetic coil adjacent to the path of the accelerated charged particles;the electromagnetic coil being configured to selectively, sequentially deflect the accelerated charged particles to impact the first, inner target material at respective different locations. 18. The system of claim 1, wherein the first, inner target material is at an oblique angle with respect to a direction of the accelerated charged particles.