The optical detectors which had been used in medical applications, and especially in radioactive treatments, need to be modified studied for the effects of radiations on them. This study included preparation of the MnS thin films in a way that vacuum thermal evaporation process at room temperature 27°C with thickness (400+-10nm) nm and a sedimentation rate of 0.39nm/sec on glass floors. The thin films prepared as a detector and had to be treated with neutron irradiation to examine the results gained from this process. The results decay X-ray (XRD) showed that all the prepared thin films have a multi-crystalline structure with the dominance of the direction (111), the two samples were irradiated with a neutron irradiation source (241Am-9Be) with activity (12 Ci) and flux (105 n/cm2.s). It emits fast neutrons from the (α, n) the first sample was irradiated for one week and the second sample was irradiated for two weeks, the X-ray diffraction (XRD) and UV-Visible Spectroscopy were examined before and after irradiation, and its properties were changed and become possible to use in optical detectors which in turn can be used in many industrial applications especially in medicine.
