Patent Number: 
Section: claims

1. An electron accelerator based method for producing molybdenum-99 (Mo-99) comprising:i) providing an electron accelerator producing a high energy electron beam;ii) providing one molybdenum converter/target unit (Mo-unit) comprising molybdenum-100 (Mo-100) wherein said Mo-unit simultaneously serves both as a braking radiation (bremsstrahlung) converter and a radioisotope production target; andiii) directing said electron beam onto said Mo-unit, thereby producing braking radiation (bremsstrahlung) which subsequently reacts in the same Mo-unit with said Mo-100 via the (γ,n) reaction to produce Mo-99 in said Mo-unit, in which the Mo-99 product accumulates;wherein said Mo-unit further comprises molybdenum-98 (Mo-98), the method further comprising slowing down the neutrons produced in step iii) with a low atomic number liquid and reacting them with said Mo-98 via the (n,γ) reaction to produce additional Mo-99 in said Mo-unit, thereby maximizing the efficiency in the production of Mo-99. 2. The electron accelerator based method of claim 1 for producing Mo-99 and other radioisotopes, further comprising the step of placing one or more external target materials outside the Mo-unit and adjacent to it so that said bremsstrahlung photons and neutrons around said Mo-unit generate further radioactive isotopes via (γ,n) and (n,γ) reactions on said one or more external target materials. 3. The method of claim 2, wherein said external target materials comprise Xe-124, and wherein said further radioactive isotopes are I-123 and I-125. 4. The method of claim 2, wherein said external target materials are selected from F-19, O-16, N-14 and C-12, and wherein said further radioactive isotopes are F-18, O-15, N-13 and C-11, respectively. 5. The method of claim 2, wherein said external target materials comprise low enriched uranium (LEU) which is used in a photo-fission (γ,f) reaction. 6. An electron accelerator based apparatus for producing molybdenum-99 (Mo-99), comprising:a) an electron accelerator producing a high energy electron beam;b) one converter/target unit made from molybdenum (Mo-unit) comprising molybdenum-100 (Mo-100) wherein said Mo-unit serves both as a braking radiation (bremsstrahlung) source and as a radioisotope production target; andc) means for directing said electron beam onto said Mo-unit to produce braking radiation (bremsstrahlung) which subsequently reacts with said Mo-100 via the (γ,n) reaction to produce and accumulate Mo-99 in said Mo-unit;wherein said Mo-unit further comprises molybdenum-98 (Mo-98), the apparatus further comprising a low atomic number liquid which slows down said neutrons produced in the (γ,n) reaction, the neutrons subsequently reacting with said Mo-98 via the (n,γ) reaction to maximize the efficiency in the production of Mo-99. 7. The apparatus of claim 6, wherein the low atomic number liquid is distilled water. 8. The method of claim 1, wherein said Mo-unit comprises natural molybdenum. 9. The method of claim 1, wherein said low atomic number liquid is water. 10. The apparatus of claim 6, wherein said Mo-unit comprises natural molybdenum. 11. The apparatus of claim 6, wherein said low atomic number liquid is water, which serves both for cooling the Mo-100 unit and for slowing down the neutrons.