Investigation of the radiation tolerance of amorphous silicon photodiodes for radiotherapy imaging

The increase radiation tolerance of structures constructed from hydrogenated amorphous silicon over similar devices constructed from crystalline silicon makes them particularly suitable for applications involving high radiation fields. One such application is in radiotherapy X-ray imaging where any detector will be exposed to the full radiation treatment beam. This paper reports the results of the 104Gy irradiation of photodiode sensors suitable for such an application and shows that they do indeed exhibit radiation tolerance. Transient effects associated with the sensors and their intensifying screens are also reported