Development of a wavelength-separated type scintillator with optical fiber (SOF) dosimeter to compensate for the Cerenkov radiation effect

The scintillator with optical fiber (sof) dosimeter consists of a miniature scintillator mounted on the tip of an optical fiber. the scintillator of the current sof dosimeter is a 1-mm diameter hemisphere. for a scintillation dosimeter coupled with an optical fiber,measurement accuracy is influenced by signals due to cerenkov radiation in the optical fiber. we have implemented a spectral filtering technique for compensating for the cerenkov radiation effect specifically for our plastic scintillator-based dosimeter,using a wavelength-separated counting method. a dichroic mirror was used for separating input light signals. individual signal counting was performed for high- and low-wavelength light signals. to confirm the accuracy,measurements with various amounts of cerenkov radiation were performed by changing the incident direction while keeping the ir-192 source-to-dosimeter distance constant,resulting in a fluctuation of <5%. optical fiber bending was also addressed; no bending effect was observed for our wavelength-separated sof dosimeter. © the author 2015.