Design of DAMC dye as a liquid scintillator for gamma ray detection

Abstract

In this work, we designed a highly sensitive liquid scintillator (LS) based on 7-Diethylamino-4-methylcoumarin (DAMC) dye to detect gamma rays and localize Compton edges (CEs). The absorption and fluorescence peaks of DAMC at a concentration of 0.03 wt%. are 350 nm and 450 nm in toluene, respectively. Typical Photomultiplier tube (PMT) photocathodes have a high quantum yield in the 400 nm–470 nm region, where DAMC emission is most intense. The LS is packaged in a standard glass container with a 2.54 × 2.54 cm diameter and height. Different gamma radiation sources, including 137Cs, 60Co, and 22Na, were used to record LS responses for varying concentrations of DAMC in toluene. The results are compared with LS of the same concentration made with POPOP. The CE was determined by fitting the shoulder and tail of the pulse height distribution spectrum with a Gaussian-based distribution technique. In short, the CE was obtained at the half-height of the gaussian based distribution's fitting. The detector model created by GEANT4, a Monte Carlo code, was compared to the theoretical and experimental results. The CE location was obtained for both ionizing radiation interactions, and scintillation photon transit was simulated using the code. Finally, the experimental spectra were compared to the GEANT4 simulation for calibration, and the CEs were located.