The "Unicorn" project, presented by the research group of Sergio Brovelli, Professor at the Department of Materials Science at the University of Milan-Bicocca, has been awarded a budget of 3 million euros over four years by the European Innovation Council (EIC), as part of the prestigious "EIC Pathfinder Open 2022" frontier research funding, allocated by the European Community to promote the development of innovative technological solutions in various scientific fields.
Unicorn" ("Hybrid nanocomposite scintillators for transformational breakthroughs in radiation detection and neutrino research", translated: "Hybrid Nanocomposite Scintillators for Transformational Breakthroughs in Radiation Detection and Neutrino Research") is coordinated by the Milan Athenaeum and involves 6 other partners, academic institutions such as Cern in Geneva, the Italian Institute of Technology, the Academy of Sciences of the Czech Republic and the Basque BCMaterials Foundation, as well as leading start-ups in photonic nanotechnologies such as Nexdot in Paris and Glass to Power in Italy.
Specifically, 'Unicorn' aims to develop scintillation detectors - which emit light when interacting with radiation - based on colloidal quantum dots, which have just been awarded the Nobel Prize in Chemistry and could be used in several strategic areas of radiation detection, including national security, medical diagnostics, environmental and industrial monitoring, clean energy production (particularly in future nuclear reactors), space exploration, and particle and high-energy physics.
The core of the scintillation detectors currently in use," says Sergio Brovelli, "are made of advanced functional materials, but they have certain limitations in their use. Those made of inorganic single crystals are very efficient, but are fragile, heavy and very expensive due to the high melting temperatures of the material. Or they are made of plastic, which is certainly cheaper and more scalable, but is more susceptible to degradation and performs much less well in measuring the energy of incident radiation. These shortcomings prevent progress in important areas of application and create a technological bottleneck for the fundamental study of rare events.
Unicorn's detectors, on the other hand, will be based on the use of innovative colloidal quantum dots, nanoscale inorganic crystals that can be chemically processed at lower temperatures - and costs - than single crystals. Colloidal quantum dots, or quantum-confined nanocrystals," Brovelli continues, "are an extremely promising class of emissive materials that are now widely used in artificial lighting and high-definition displays. In Unicorn, they will be specially engineered to interact with radiation and then embedded in plastic matrices. The body of the device will therefore be plastic, but the active part that interacts with the radiation will be the quantum dots. This will improve the energy resolution, efficiency and stability of the devices, allowing them to be scaled up for both industrial and scientific applications. There will also be an advantage in terms of design flexibility.
The ultimate goal of the project is to study neutrino-free double-beta decay, a process that could shed light on many unresolved aspects of modern particle physics and cosmology. "A rare nuclear process," explains Luca Gironi, Professor at the Department of Physics of the University of Milan-Bicocca, who is also part of the project team, "whose existence has only been hypothesised and not yet observed, but which could provide long-sought answers about the origin of the universe. In presenting 'Unicorn', we and the partner institutions asked ourselves what was the most difficult device to build, and the answer was: a detector to observe the process of double beta decay without neutrinos, from which the neutrino mass could be deduced. In this scientific challenge, of which we do not know whether it will be successful or not, every experiment and every result will represent progress in the field of scintillation radiation detectors.