Neutron irradiation on carbon nanocapsules

Carbon nanocapsules containing nanometer-size particles of molybdenum carbide have been irradiated by neutrons of flux 1014 N cm−2 s−1 for 6 days. The γ-ray spectrometry shows 1010 Bq g−1 of Mo-99 which is transformed from Mo-89 and decays into Tc-99. Our investigation by transmission electron microscopy indicates that the nanocapsule is robust against our neutron irradiation and used as a container for radioactive materials and tracer elements. The contents of the capsule in the nanometer scale are activated and transformed into other nuclei.