Metal oxide nanoparticle-loaded plastic scintillator using fluorophore PTP+POPOP for high energy X-ray detection

We have developed heavy-metal-oxide nanoparticle loaded plastic scintillators (High-Z PLSs) for high energy X-ray detection. The High-Z PLS loaded with the surface-modified ZrO
2
, HfO
2
and Bi
2
O
3
nanoparticles is useful for high-energy X-ray measurements of up to a high count-rate > 10
⁷
s
^-1
with an improved detection efficiency. Here we present test results on the High-Z PLSs with a two-component fluorophore of p-terphenyl (PTP) and 1,4-Bis[2-(5-phenyloxazolyl)]benzene (POPOP). The fluorophore has a maximum emission wavelength of ~420 nm and is suitable for common photomultipliers. The High-Z PLSs successfully maintained transparency, after polymerization by mixing monomers, consisting mainly of vinyltoluene. Test samples of the High-Z PLSs (8 mm in diameter, 3 mm thick) were prepared for 10 wt% and 20 wt% Zr, Hf and Bi elements. Properties of each sample were investigated using 67.41 keV synchrotron X-ray beam at beamline BL-14A of the Photon Factory (PF), KEK. The detection efficiency reached 48.6 ± 0.5% for a Hf 20 wt% loaded PLS. We will present the results for count-rate measurement using an X-ray scintillation detector with Hf 28 wt% loaded PLS (25 mm in diameter, 5 mm thick) and a common photomultiplier at 60.00 keV.