Project title: Development of free-standing low-density foam targets for ELI-NP experiments

Acronim:  ELIFOAM

Project code:  ELI-RO/RDI/DEZ/DFG/2025_020

Project director (INFLPR): Dr. Mihaela Filipescu

Project responsible (IFIN-HH): Dr. Constanta Cristina Gheorghiu

Funding: 4.000.000 lei

Abstract: The launching of the LDE/IV.2 Targets high power laser experiments and their characterization, ELI-NP thematic competition gives a multidisciplinary team of researchers the opportunity to focus their attention on advancing the fusion-based energy production emergent field. For this purpose, a project “Development of free-standing low-density foam targets for ELI-NP experiments (ELIFOAM)”, which addresses the developing of free-standing low-Z foam targets (carbon and boron based) for enhancing the know-how in the fusion-energy related research is proposed. ELIFOAM project will be carried out as a partnership among two multidisciplinary teams from INFLPR and IFIN-HH, which will join efforts to fabricate and thoroughly characterize the proposed advanced targets. Taking advantage of the acquired expertise on carbon-based target fabrication (foam targets) using the Pulsed Laser Deposition method among other available techniques, a new direction in boron-based foam targets is fabrication proposed for laser-driven proton-boron nuclear fusion experiments. The proton-boron reaction (the reaction between hydrogen and boron-11 nucleus) is a promising solution to a safe, large scale and clean energy production. In this reaction, non-pollutant and non-radioactive three alpha-particles (helium nuclei) are produced along with 8.7 MeV of energy, however, there are several challenges to overcome (e.g. higher ignition temperatures for p-B fusion and intense bremsstrahlung radiation). Proton-boron fusion experiments can be optimized by improving the targets used in the experiments. Using boron-based foams as targets (with extreme low-density, few mg/cm3), higher proton fluxes are expected and an increased laser absorption efficiency compared to flat foils. The ELIFOAM project is divided into three stages: I. Configurations and preliminary experiments, II. ELIFOAM workflow optimization, manufacturing and advanced characterization, III. Scaled-up production of optimized foam targets and validation of ELIFOAM outcomes in the ELI-NP framework. The assessment of the most suited fabrication method (Pulsed Laser Deposition, Matrix-Assisted Pulsed Laser Evaporation, Thermal Evaporation) of free-standing low-Z low-density targets will be achieved at INFLPR, which, together with complementary experiments carried out at ELI (Physical Vapor Deposition method or Sol-gel chemical method combined with supercritical drying) will allow the supply of targets for efficient fusion schemes. Throughout the manufacturing process, a detailed characterization of the targets will be performed using the available analysis techniques, ensuring the required purity, density, morphology, flatness, isotopes identification, and overall quality of the targets. Continuous optimization and refinement of the process parameters, along with tests on the manufactured targets will be performed until the completion of the project. Identified risks are mitigated through contingency plans, collaboration and prioritization. ELIFOAM envisions scientific and technological advancement and economic benefits. ELIFOAM invests in people: two open positions, students (BSc/MSc/PhD) are integrated early and trained for foam target fabrication, characterization and ELI-NP validation. Here, we focus on recruitment, mentorship, authorship and open access to equipment based on gender equality principles.