Patent Number: 
Section: claims

1. A shield for absorbing high level radiation emitted during generation of a radioisotope, comprising:an inner portion fabricated from a first type of shielding material for shielding against a first type of high level radiation; andan outer portion fabricated from a second type of shielding material for shielding against a second type of high level radiation wherein the inner and outer portions are part of a shield arrangement adapted to shield against high level radiation and wherein the outer portion serves as a mold for forming the inner portion. 2. The shield according to claim 1 wherein the inner portion is fabricated from concrete. 3. The shield according to claim 1 wherein the outer portion is fabricated from high density polyethylene. 4. The shield according to claim 1 wherein additional shielding elements different from the first type of shielding material are embedded in the inner portion and wherein the shielding elements also reinforce the inner portion and do not become radioactive due to generation of the radioisotope. 5. The shield according to claim 4 wherein the shielding elements are fabricated from fiberglass. 6. The shield according to claim 1 further including additional shielding materials located adjacent to the inner portion. 7. The shield according to claim 1 wherein outer portion is formed by using a rotomolding process. 8. The shield according to claim 1 wherein the outer portion is formed by using a blow molding or an injection molding process. 9. The shield according to claim 1 further including ribs for supporting the outer portion. 10. The shield according to claim 1 wherein the radiation is generated by accelerating a particle beam and bombarding a target material with the particle beam. 11. The shield according to claim 1 wherein the inner portion shields against gamma rays. 12. The shield according to claim 1 wherein the outer portion moderates neutrons. 13. A particle accelerator system, comprising:a particle accelerator for generating a particle beam that bombards a target to generate a radioactive isotope wherein high level radiation is produced during generation of the radioisotope; anda shield used as part of a shield arrangement for absorbing high level radiation emitted during generation of the radioisotope wherein the shield includes an inner portion fabricated from a material which is adapted to shield against gamma rays and an outer portion fabricated from a material which is adapted to moderate neutrons wherein the outer portion serves as a mold for forming the inner portion. 14. The shield according to claim 13 wherein the inner portion is fabricated from concrete. 15. The shield according to claim 13 wherein the outer portion is fabricated from high density polyethylene. 16. The shield according to claim 13 wherein additional shielding elements having shielding properties different from that of the inner portion are embedded in the inner portion and wherein the shielding elements also reinforce the inner portion and do not become radioactive due to generation of the radioisotope. 17. The shield according to claim 16 wherein the shielding elements are fabricated from fiberglass. 18. The shield according to claim 13 further including additional shielding materials located adjacent to the inner portion. 19. The shield according to claim 13 wherein outer portion is formed by using a rotomolding process. 20. The shield according to claim 13 wherein the outer portion is formed by using a blow molding or an injection molding process. 21. The shield according to claim 13 further including ribs for supporting the outer portion. 22. A method for forming a shield for absorbing high level radiation emitted during generation of a radioisotope, comprising the steps of:providing an outer portion of the shield, wherein the outer portion is fabricated from a first type of shielding material for shielding against a first type of high level radiation, and;using the outer portion to form an inner portion of the shield, wherein the inner portion is fabricated from a second type of shielding material for shielding against a second type of high level radiation wherein the inner and outer portions are part of a shield arrangement adapted to shield against high level radiation.