The single-photon emission computed tomography (SPECT) and positron emission tomography (PET) have been widely adopted for nuclear medicine imaging to make diagnoses of body functions, identification of site of cancers, and so on. Now, almost all of medical radio isotopes are produced by nuclear reactors or charged particle accelerators. We propose a new route to produce the medical radio isotopes with acclerator-based neutron sources. In this paper, as an example, we introduce the proposed production method of 99Mo, which is the mother nuclide of 99mTc for SPECT. We determined the 100Mo(n,2n)99Mo reaction cross section to 1,415±82 mb and it was consistent with the value (1,398mb) obtained from JENDL-4.0. Therefore, it indicates yields of produced RIs can be predicted with nuclear data based simulations. The simulation also can be used to design irradiation condition. In this paper some results of the simulations are also shown.
