Understanding the behaviour of different metals in loaded scintillators: discrepancy between gadolinium and bismuth

Guillaume H. V. Bertrand (1) , Jonathan Dumazert (1) , Fabien Sguerra (1) , Romain Coulon (1) , Gwenolé Corre (1) , Matthieu Hamel (1)

1 LCAE (CEA, LIST) - Laboratoire Capteurs et Architectures Electroniques (CEA, LIST)

Organometallic chemistry has recently gained a lot of attention in the domain of plastic scintillators. Homogenously dispersed metal complexes in a polymer matrix can afford plastic scintillators with unseen abilities. Heavy atom loading is very attractive as it gives access to plastics with increased sensitivity towards elusive radiations such as gamma and neutron. But this comes with a drawback, as heavy atoms tend to quench fluorescence, hence decreasing the scintillation yield. We present here a comprehensive study of this phenomenon with bismuth and gadolinium complexes. We investigate the influence of the ligand nature by varying organometallic and fluorophore concentration to probe their interaction. We also propose an explanation of the difference in behavior between these two metals. These results were applied to the fabrication of large volume loaded plastic scintillators (>100 cm3). Bismuth loaded scintillators displayed characteristics equivalent to lead loaded commercial materials, and gadolinium samples proved to be able to capture thermal neutrons and release gamma rays

Mots clés: nuclear instrumentation; gadolinium; plastic scintillator; bismuth; instrumentation

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Instrumentations et Détecteurs [physics.ins-det]

Guillaume H. V. Bertrand, Jonathan Dumazert, Fabien Sguerra, Romain Coulon, Gwenolé Corre, et al.. Understanding the behaviour of different metals in loaded scintillators: discrepancy between gadolinium and bismuth. Journal of Materials Chemistry C, 2015, 3 (23), pp.6006-6011. ⟨10.1039/C5TC00387C⟩. ⟨hal-01904698⟩