Patent Number: 
Section: claims

1. A Radioactive Isotope (RI) manufacturing apparatus comprising:an accelerator which accelerates charged particles;a target which is irradiated with the charged particle accelerated by the accelerator,thereby manufacturing a radioactive isotope;a built-in shield that is a wall body which is configured to be provided inside a building and surrounds the accelerator and the target to shield radiation; anda target shield that is a wall body which is disposed in an internal space formed so as to be surrounded by the built-in shield and surrounds the target to shield the radiation; wherein, said target shield is connected to the lead-out tube at the bottom of the shield in order to further attenuate radiation. 2. The RI manufacturing apparatus according to claim 1, wherein the target shield includesa gamma ray shielding plate which shields gamma rays, anda neutron radiation shielding plate which is disposed on the target side of the gamma ray shielding plate and shields neutron radiation. 3. The RI manufacturing apparatus according to claim 1, wherein the built-in shield is composed of a plurality of parts and at least one of the plural parts is movable,the target shield includes an openable and closable door, anda joint between the door and another member adjacent to the door is formed at a position deviated from a joint between the plural parts of the built-in shield. 4. The RI manufacturing apparatus according to claim 1, wherein a cutout portion which makes a lead-out tube that leads out the radioactive isotopes in the target pass therethrough is provided on the lower surface side of the target shield.