Patent Number: 
Section: claims

1. A radioisotope production apparatus which irradiates a target material with a charged particle beam to produce a radioactive isotope, the apparatus comprising:a particle accelerator which emits the charged particle beam along a predetermined beam axis;a first target portion on which the charged particle beam emitted from the particle accelerator is incident and through which the charged particle beam passes; anda second target portion on which the charged particle beam having passed through the first target portion is incident,wherein the first target portion includes:a body barrel portion,a beam passage which is formed through the body barrel portion and through which the charged particle beam passes,a target holder which is attachable to and detachable from the body barrel portion,a target material holding portion which is formed in the target holder and is configured to hold a first target material on the beam axis in the beam passage, anda cooling gas supply unit which supplies a cooling gas for cooling the first target material;wherein the second target portion includes:a body portion,a substrate holding portion which is formed in the body portion and is configured to hold a target substrate, the target substrate includes a substrate body and a second target material provided on the substrate body, on the beam axis, anda cooling water supply unit which supplies cooling water for cooling the target substrate to a downstream-side surface of the target substrate with respect to the charged particle beam; andwherein a total thickness of the first target material and the target material holding portion of the first target portion on the beam axis is smaller than a thickness of the target substrate on the beam axis. 2. The radioisotope production apparatus according to claim 1,wherein the first target portion includes a plurality of the target material holding portions. 3. The radioisotope production apparatus according to claim 1,wherein the first target material is inserted onto and extracted from the beam axis in a direction intersecting the beam axis.