SPES_MED (INFN-CSN3, 2025-2027)

SPES_MED, is a 3-years project funded by CSN3 of INFN and focused on SPES (Selective Production of Exotic Species) facility. The heart of SPES is the 70 MeV proton-cyclotron having a dual-beam extraction, installed and commissioned in a new building equipped with ancillary laboratories currently under construction. The SPES main goal is the realisation of an advanced ISOL (Isotope Separation On-Line) facility to produce re-accelerated exotic ion beams for fundamental nuclear physics studies. The cyclotron double-beam extraction system allows to simultaneously carry out applied research, such as radionuclides production for medicine (SPES-γ). The SPES_MED project gathers the interdisciplinary communities of the LARAMED (LAboratory of RAdionuclides for MEDicine) and ISOLPHARM (ISOL technique for radioPHARMaceuticals) projects.

The main objectives of SPES_MED are: 1. Perform measurements of nuclear cross sections aiming at the optimization of medical radionuclides production, also using nuclear modelling tools to find out the best irradiation conditions; 2. Provide a precise measurement of the ISOL production yields originating from SiC and TiC targets; 3. Compare the produced data with the existing simulation libraries, with the purpose of providing an experimental benchmark when the theoretical predictions fail. The project is structured considering 3 work packages (WP), whose goals are summarised below. The SPES_MED project is lead by the national responsible Emilio Mariotti and comprises the Pisa, Milano, Padova, Pavia divisions and the Legnaro National Laboratories.

WP1. Nuclear cross section measurements (coordinated by Lucia De Dominicis and Michele Colucci): measure unexplored nuclear reactions leading to the production of both the radionuclide of interest and its contaminants, aiming to find out the best irradiation parameters for each specific case. The main nuclear reactions of interest are ⁴⁹Ti(d,x)⁴⁷Sc, ^68,70Zn(p,x)^67,64Cu, ¹⁵⁹Tb(p,5n)¹⁵⁵Dy → ¹⁵⁵Tb (also in the framework of the PRIN PNRR 2022 APHRODITE-155), ^natEu(a,x)¹⁵⁵Tb, ^natGd(p,x)^152,149Tb, ^natGd(a,x)^152,155Tb.

WP2. ISOL production yield measurements (coordinated by Pasquale Delogu and Alberto Arzenton): measure the ISOL production yield of relevant medical radionuclides and acquire in-depth understanding of the elements that can increase their production. This measurements will help to establish the yield database of the SPES facility, focusing the main efforts on the study of silicon carbide (SiC) targets, for the producti on of ²⁸Mg, titanium carbide (TiC) targets, for the production of ⁴³K and, possibly, ⁵¹Cr. Further measurements will then allow to determine, for each element of interest, the two main factors affecting the global ISOL production yield, explicitly the SPES target release efficiency, the best ion source technology and its efficiency.

WP3. Modeling and Monte Carlo simulations (coordinated by Francesca Barbaro and Lisa Zangrando): simulate high-purity radionuclide production for medical applications through nuclear reactions and examine different models for the nuclear reaction mechanisms analysis. Two main sets of simulations will be run:

• Cross sections studies: cross sections will be computed using codes such as TALYS or EMPIRE, and different models will be considered for the analysis, with the main objective of optimising the irradiation parameters. The simulations’ outcomes will then be compared with experimental results. A collaboration with experimentalists and medical physicists will guide measurements and dosimetric assessments, particularly focusing on the impact of contaminants.

• In-target production analysis: different Monte Carlo codes (MCNP, PHITS, FLUKA, and Geant4) will be employed to precisely simulate the nuclear interactions. To simulate the radioisotope formation and decay at different times during the irradiation period and in the following cooling phase, the aforementioned codes have to interface with nuclide evolution programs. Due to the complexity of the calculation procedure, a high number of simulation events is requested to reach a reliable statistical precision. Therefore, the CloudVeneto infrastructure, which provides an advanced IT Platform for parallelizing MC codes (FLUKA and Geant4) in Cloud, will be employed.