Radioisotopes produced by neutron irradiation of food

The use of neutrons for cargo interrogation has the potential to drastically improve threat detection. Previous research has focussed on the production of 24Na, based on the isotopes produced in pharmaceuticals and medical devices. For both the total activity and the ingestion dose we show that a variety of isotopes contribute and that 24Na is only dominant under certain conditions. The composition of the foods has a strong influence on the resulting activity and ingestion dose suggesting that the pharmaceuticals and medical devices considered initially are not a viable analogue for foodstuffs. There is an energy dependence to the isotopes produced due to the cross-sections of different reactions varying with neutron energy. We show that this results in different isotopes dominating the ingestion dose at different energies, which has not been considered in the previous literature. •We show that neutron interrogation of food can produce many radioisotopes.•We show a strong dependance between food and certain radioisotopes.•Some isotopes are shown to have an energy dependence.•Previous claims that 24Na is the main threat is shown to only apply in special cases.