RESUMEN
The high energy electrons produced by linear accelerators can generate several radioisotopes by means of photonuclear reactions. The activity produced in the head of a 15 MV Mevatron Siemens 77 medical linear accelerator was measured by high resolution gamma-ray spectrometry, during its decommissioning 1 year after the last clinical use. The activity of 54Mn, 57Co, 60Co, 181W, and 65Zn was measured while the activity of other radioisotopes which emit soft beta or gamma rays such as 59Ni, 63Ni, and 55Fe was inferred by appropriate scaling factors. The number of pieces requiring particular care is limited, their mass does not exceed some tens of kilograms, and their volume is of the order of some thousands of cm3. Moreover, these materials are metals and the emitted radiation can be easily shielded, so that storage should not create particular problems.
Asunto(s)
Aceleradores de Partículas , Oncología por Radiación/métodos , Radioisótopos/uso terapéutico , Electrones , Diseño de Equipo , Rayos gamma , Metales/química , Modelos Estadísticos , Fotones , Oncología por Radiación/instrumentación , Dosificación Radioterapéutica , Reproducibilidad de los Resultados , Dispersión de Radiación , Espectrofotometría/métodos , TungstenoRESUMEN
Neutrons can be produced with low-energy ion accelerators for many applications, such as the characterisation of neutron detectors, the irradiation of biological samples and the study of the radiation damage in electronic devices. Moreover, accelerator-based neutron sources are under development for boron neutron capture therapy (BNCT). Thin targets are used for generating monoenergetic neutrons, while thick targets are usually employed for producing more intense neutron fields. The associated photon field produced by the target nuclei may have a strong influence on the application under study. For instance, these photons can play a fundamental role in the design of an accelerator-based neutron source for BNCT. This work focuses on the measurement of the photon field associated with neutrons that are produced by 4.0-6.8 MeV protons striking both a thin 7LiF target (for generating monoenergetic neutrons) and a thick beryllium target. In both cases, very intense photon fields are generated with energy distribution extending up to several MeV.