Optimization of phosphor concentration of surface-modified Bi2O3 nanoparticle-loaded plastic scintillators for high-energy photon detection

In this study, the 3-phenylpropionic acid (3-PPA)-modified Bi2O3 nanoparticle-loaded plastic scintillators were synthesized to obtain fast scintillators having high detection efficiency of high-energy X-rays. To reach a high light yield, the content of 2-(4-tert-butylphenyl)-5-(4-phenylphenyl))-1,3,4-oxadiazole (b-PBD) in the plastic scintillators was optimized. The detection efficiency for high-energy photons was enhanced by the incorporation of surface-modified Bi2O3 nanoparticles of less than 10 nm into scintillators at 5 or 10 wt%. In the pulse-height spectra, the photoelectric peak positions were located at the highest channels for the samples containing 0.50 or 1.0 mol% b-PBD regardless of the Bi concentration. The photoelectric peak positions shifted to lower channels with a further increase in the b-PBD concentration, which indicates that the light yield decreased due to concentration quenching. In addition, the time resolution of the detector equipped with the studied samples was of the sub-nanosecond scale, suggesting that they had a very fast response.

Automated summary

The study synthesized 3-phenylpropionic acid (3-PPA)-modified Bi2O3 nanoparticle-loaded plastic scintillators to achieve fast scintillators with high detection efficiency of high-energy X-rays. By optimizing the content of b-PBD in the plastic scintillators and incorporating surface-modified Bi2O3 nanoparticles, the detection efficiency for high-energy photons was enhanced. The detectors equipped with the studied samples showed sub-nanosecond scale time resolution, indicating a very fast response.