Feasibility of a position-sensitive Cherenkov radiation detector using a reflector-coated liquid light guide

In this study, a Cherenkov radiation sensor was developed utilizing a reflector-coated liquid light guide (LLG). In the proposed configuration, a reflector replaced one of the two photomultiplier tubes (PMTs), forming the core sensing element alongside the LLG, with gamma-ray (⁶⁰Co and ¹³⁷Cs) and a beta-ray (⁹⁰Sr) emitters employed to assess its performance as a position-sensitive detector. The time-of-flight method was utilized to determine time differences corresponding to source positions. Position spectra were generated based on these time differences, with the Cherenkov radiation count rates compared across different types of reflectors to identify the optimal choice. We compared position spectra obtained from two PMTs and one PMT with a reflector, confirming the ability to detect multiple sources. Subsequently, each source was positioned perpendicular or parallel to the sensor axis to capture position spectra. The results demonstrate the sensor's potential as a long-distance position-sensitive detector. By leveraging the simplicity of a single PMT system, the proposed sensor facilitates challenging tasks such as pipeline inspection or non-destructive testing of radioactive waste drums.