Development of a flexible γ-ray detector using a liquid scintillation light guide (LSLG)

Area of Science:

• Nuclear Physics
• Radiation Detection and Measurement
• Scintillation Detector Technology

Background:

• Traditional gamma detectors often lack flexibility, limiting their use in confined or complex geometries.
• Liquid scintillation light guides (LSLGs) offer potential for flexible radiation detection but require optimization for accurate dose rate measurements.
• Understanding the relationship between LSLG parameters and pulse height analysis (PHA) is crucial for developing practical detectors.

Purpose of the Study:

• To develop and characterize a flexible gamma detector utilizing a liquid scintillation light guide (LSLG).
• To investigate the influence of LSLG physical properties and gamma ray source positioning on the PHA spectrum.
• To establish the feasibility of using the developed LSLG detector for radiation dose rate determination and contamination detection.

Main Methods:

• Fabrication of a flexible LSLG detector.
• Analysis of pulse height (PHA) spectra under varying LSLG dimensions (diameter, length), scintillator concentration, and gamma ray irradiation distances from the photomultiplier tube (PMT).
• Comparison of dose rate measurements with a conventional NaI(Tl) scintillation detector.

Main Results:

• The PHA spectrum was found to be dependent on LSLG diameter, length, scintillator concentration, and distance from the PMT.
• A linear decrease in the count ratio between two divided channel regions was observed as the distance from the PMT increased.
• The count rate of the flexible LSLG detector, when configured in a circular shape, showed a direct proportionality to the radiation dose rate measured by a standard NaI(Tl) detector.

Conclusions:

• A flexible and elongated LSLG detector using a single PMT is effective for determining radiation dose rates.
• The developed detector demonstrates potential for identifying localized radioactive contamination, particularly in narrow or restricted spaces.
• The findings support the utility of LSLGs as adaptable tools in radiation monitoring and safety applications.