134Cs—a potential radionuclide for radiation therapy

Caesium 134, with a half life of 2.06 years and emitting 2.23 photonos of 0.7 MeV average energy per disintegration, has not been considered so for in radiotherapy. It decays (Lederer et al., 1967) by β-emission to stable 134Ba as shown in Fig. 1. The maximum energy of the electrons in 0.66 MeV. The expected photons and the respective yields are given in Table I.