Polysiloxane hybrid/Organic Scintillator
Jonathan Arrue
Abstract: Many plastic organic scintillators are capable neutron and photon detection by pulse shape discrimination (PSD). This is only possible by overdoping (>20wt.%) them with florescent molecules, which leads to negative long-term effects such as a poor glass transition temperature or the dopant itself precipitating over time. Polysiloxanes require far less dopant (around 4 wt.%) for similar neutron and photon discrimination while mitigating the negative long-term effects. Polysiloxane, however, is a broad term that only refers to a polymer of silicon atoms bonded to 2 oxygen atoms and two organic functional groups. In collaboration with Colorado School of Mines, we found these specific functional groups can enhance or hinder the detector performance. For example, polysiloxanes have a higher light output and better discrimination when the functional groups are methyl and phenyl groups when compared to only phenyl groups. The objective of this research is to best optimize the chemistry of the polysiloxanes for the highest discrimination and light output.