HANSOME wants to the create hafnia based scintillating composites (Fig.1) with satisfactory timing performances for fast timing applications. For the first time, hafnia NS were produced by the scalable and reliable photo-induced synthesis (Fig.2). After the synthesis the NS were subjected to annealing treatment at high temperature. HANSOME evidenced that these thermal treatments allow to increase the crystallinity degree and to improve the light output of the NS. These NS have a blue emission under excitation (see photo (PL) -and radio (RL) luminescence in Fig. 3); the colour of the light and the lifetime are appropriate to promptly excite the fast emission of many organic moieties suitable for fast timing techniques. Once validated their spectral features, HfO2 NS were embedded with a fast organic dye into a plastic matrix for the creation of composite scintillators (Fig.4-6). The activation of the dye emission by transfer of energy from the NS was explored in the final composite material under ionizing radiation, such as X-rays. HANSOME findings revealed that the use of NS is essential to improve the efficiency of the emission and timing performance of the dye in the composite scintillators. Especially, the composite scintillator prototype made by 1% of NS incorporated in the plastic host with dye showed performances similar to the ones of standard scintillators commercially in use.
HANSOME suggests the benefits of creating this kind of hafnia-based composites scintillators that depend on many aspects, such as the low cost of production and the chance to tune their spectroscopic/timing properties, by simply adjusting the physico-chemical properties of the components, their design, and concentrations in the polymeric matrix, according to the qualities requested by the specific fast timing applications.
The findings of the project were presented in 5 international conferences. At LUMDETR conference in 2021, the oral contribution received the Best Oral Presentation Award. Further, the findings of the project were regularly shared during seminars and meetings with the groups of FZU in Prague, and with the industrial partners and scientific collaborators. The development of the project allowed the publication of 5 papers in international peer-reviewed journals, among which one in Nature Communication.
