Molybdenum-converter based electron linear accelerator and method for producing radioisotopes
View Patent ↗The present invention provides a method for producing molybdenum-99 comprising: i) providing an electron accelerator; ii) providing a molybdenum converter/target unit (Mo-CTU) comprising one or more metallic components, wherein each one of said metallic components is made of a material selected from the group consisting of natural molybdenum, molybdenum-100, molybdenum-98, and mixtures thereof; iii) directing an electron beam generated via said electron accelerator onto said Mo-CTU to produce a braking radiation (bremsstrahlung); iv) employing said bremsstrahlung onto said Mo-CTU to produce molybdenum-99 and neutrons via a photo-neutron reaction; v) slowing down the neutrons produced in step iv) with a low atomic liquid, e.g. distilled water; and optionally vi) employing the neutrons produced in step iv) to produce a complementary amount of molybdenum-99 via a neutron capture reaction on said Mo-CTU. The invention further provides an apparatus for producing molybdenum-99.
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; and
iii) 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; and
c) 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.