Development of Compact Gamma Camera for Real-time Radiation Monitoring at Nuclear Power Plants

초록

Gamma-imaging system is of great interest to monitor the contamination of radioactive substances in a wide range of areas at nuclear power plants. The purpose of this study was to develop a compact gamma camera capable of detecting and imaging the radioactive sources present in contaminated area. The prototype of compact gamma camera with 73 x 99 mm(2) FOV was composed of pinhole collimator, SiPM based detector and dedicated electronics. Flood image and energy spectrum were acquired to evaluate the performance of the prototype gamma camera. Energy linearity of the system was measured with Co-57, Ba-133, Mn-54, Na-22 and Eu-152 point sources. Spatial resolution and sensitivity of the prototype gamma camera were also measured. Each crystal pixel was clearly identified in the acquired flood histogram, average energy resolution of 384 crystals was 18.5 +/- 1.5% Adjusted R-squared value of linear fitting for ADC values was 0.99 in the range of 122 keV to 1408 keV. Spatial resolution and sensitivity were 12.4 mm and 753 cps/MBq at a distance of 1000 mm from the collimator. Preliminary experimental results showed its capability of use at nuclear power plants confronting radioactive sources emitting wide energy range of radiations.