Mercoledì del PRIN n.6: Annamaria Mazzone – Amina Antonacci

RAdiation DAMagE in Structural material of fusion reactors under neutron irradiation: cross section measurements and material testing protocols (RADAMES)

Dr. Annamaria Mazzone

The proposal aims at addressing the problem of radiation damage of structural material in fusion reactors. The extremely high neutron flux generated in the plasma is expected to limit severely the lifetime of several components, such as the mantle and the divertor, of future fusion power plants. Apart from atom displacement, causing defects in the material structure, neutrons induce nuclear reactions that result in transmutation, altering the chemical composition of the material, or in the production of gas (hydrogen and helium), responsible for bubble formation leading to embrittlement and changes of the material thermo-mechanical properties. To estimate the lifetime of the reactor components under neutron irradiation, a wide range of nuclear data are needed, in particular on neutron-induced reaction cross sections up to 14 MeV, the energy of neutrons produced in the D+T reaction. Experimental studies of radiation damage in structural materials of fusion reactors are expected to take place at dedicated neutron irradiation facilities, like IFMIF and its intermediate step DONES, now under construction. The neutron energy spectrum at these facilities, however, presents a high-energy tail extending up to several tens of MeV, well above the energy of fusion neutrons. The contribution of this tail to the radiation damage must be properly evaluated and accounted for to correctly infer the reactor components’ lifetime from irradiation tests at IFMIF-DONES. At present, this can only be done based on high-energy neutron reaction data that, however, are either completely missing or very scarce. The lack of data is an important issue hampering accuratee valuation of neutron damage in fusion.

We propose to perform measurements of neutron-induced reactions relevant for fusion energy at the n_TOF spallation neutron source at CERN. The innovative features of the neutron beam, i.e. the high flux and the wide energy range, combined with high-performance detectors now being developed, and with the use of highly reliable Monte Carlo simulation tools in the data analysis, will lead to much-needed data for the assessment of neutron damage in structural components of fusion reactors. In a multi-disciplinary approach, this project aims at defining a protocol for testing the material properties after irradiation and at studying the feasibility of monitoring techniques based on the variation of material physical properties. This last task of the project will set the basis for the future participation of the proponents in the international effort for the experimental determination of neutron damage on structural material in fusion power plants.

Keywords

1. Fusione nucleare
2. Danno da radiazione di neutroni
3. Materiali strutturali

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BIO-circular 3D-printable prodUctS for cultural heriTage (BIO-DUST)

Dr. Amina Antonacci

The BIO-DUST project aims to create an innovative green product derived from waste for use in 3D printing to restore missing pieces of statues and to produce replicas of artworks for museums. In alignment with circular economy principles, this product will be synthesized using waste from the food industry. By combining inorganic additives with polysaccharides extracted from microalgae cultures, we will develop safe, environmentally friendly, and non-toxic compounds. This product will be crucial in the cultural sector, facilitating research, documentation, restoration, and educational initiatives. It will enhance accessibility by incorporating tactile elements into cultural experiences, benefiting individuals with learning difficulties, children, the elderly, and visitors who are blind or visually impaired. Moreover, comprehensive characterization of the new product, from raw materials through the entire production process, will enable the assessment of its potential applications in other fields, thereby amplifying the research impact.

To this purpose, the characterization of the raw materials was carried out. In particular, inorganic samples, such as hydroxyapatite and biochar, were extracted from animal bones and mollusk shells or synthesized through acid precipitation and calcination. These samples were characterized using X-ray powder diffraction and SEM-EDX electron microscopy.

Additionally, a screening of three types of microalgae (green algae, red algae, and cyanobacteria) was conducted to identify the best polysaccharide producers. A sustainable protocol for polysaccharide extraction was established, and the microalgal extracts were quantified and characterized using spectroscopy (UV-Vis and FTIR), Bradford assay, elemental chemistry analysis, and GC-MS.

Future studies will be focused on the development and detailed characterization of the new biomaterial, as well as its practical application in 3D printing.

Keywords:

1. microalgae;
2. polysaccharides;
3. circular economy;
4. 3D-printing