An Investigation on γ induced activation reactions on human essential elements

In radiotherapy, the energy of the γ rays used could be larger than 10 Me V, which would potentially activate stable nucleus into a radioactive one. The γ induced reactions on some of the human essential elements are studied to show the probability of changes of nuclei. The Talys 1.4 toolkit was adopted as the theoretical model for calculation. The reactions investigated include the（γ, n） and（γ, p） channels for the stable Na, Mg, Cl,K, Ca, and Fe isotopes, with the incident energy of γ ranging from 1 to 30 Me V. It was found that the cross sections for the reactions are very low, and the maximum cross section is no larger than 100 mb. By considering the threshold energy of the channel, the half-life time of the residue nucleus, and the percentage of the element accounting for the weight and its importance in the body, it is suggested to track the radioactive nuclei22 Na,41Ca, and42,43 K after γ therapy. The results might be useful for medical diagnosis and disease treatment.