de León Martínez, Héctor Asael; Rivera Pérez, Esteban; Gallego Díaz, Eduardo; Lorente, Alfredo; Vega Carrillo, Héctor René
Resumen:
When linacs operate above 8 MV an undesirable neutron field is produced whose spectrum
has three main components: the direct spectrum due to those neutrons leaking out from the
linac head, the scattered spectrum due to neutrons produced in the head that collides with
the nuclei in the head losing energy and the third spectrum due to room-return effect; this
last are mainly epithermal and thermal neutrons being constant at any location in the
treatment hall. These neutrons induce activation mainly in the concrete walls and the linac
components. Here the induced radioisotopes have been identified in concrete samples
located in the hall and in one of the wedges. The identification has been carried out using a
gamma-ray spectrometer.