Speaker
Description
Laser–plasma radiation sources based on solid targets [1] are promising for a wide range of applications, from nuclear medicine to materials characterization. They are attractive because they can generate various types of radiation (e.g., high-energy electrons, ions, neutrons, and γ-rays), allow for energy tuning, and can operate within compact setups. This versatility relies on the precise control of laser and plasma parameters, which requires a solid understanding of plasma physics. The precise tailoring of plasma properties — by tuning laser intensity, target composition, thickness, and surface conditioning — enables control over the maximum energy of the accelerated particles [2, 3]. Therefore, laser–plasma radiation sources represent promising alternatives to conventional accelerators which, although based on mature technologies, remain limited in terms of flexibility and compactness.
Particle-Induced X-ray Emission (PIXE) and X-ray Fluorescence Spectroscopy (XRF) are complementary materials characterization techniques used in several fields, including artwork analysis [4]. They rely on the irradiation of samples with protons and photons to induce characteristic X-ray emission. As shown in recent proof-of-principle studies [5–7], PIXE and XRF could benefit from the use of laser–plasma radiation sources in the near future. Indeed, the energies of the accelerated particles and emitted photons are perfectly compatible with those required for the characterization of cultural-heritage materials.
This contribution presents our activities at Politecnico di Milano devoted to the development of laser–plasma radiation sources for materials characterization. We show our advances in terms of targets production (deposited metallic foils and near-critical double-layer targets), and we show its fundamental role in tuning the laser-plasma emitted radiation. Experimental and numerical results of laser-plasma interaction involving our targets are shown as well. Then, a study, performed with the ELIMAIA beamline [8] of the ELI Beamlines facility, of laser-driven PIXE and XRF techniques for the analysis of cultural-heritage materials is presented. Using a proof-of-principle setup [9], laser–plasma–emitted protons and photons were transported in air to irradiate certified reference materials, medieval bronzes, and Roman ceramics. By measuring the emitted characteristic X-rays, the composition of the irradiated samples was determined. This study lays the foundation for the development of laser–plasma accelerators tailored to the characterization of cultural-heritage materials, suggesting that this approach could achieve results comparable to those obtained with conventional sources, while maintaining the inherent versatility of laser-plasma systems.
[1] A. Macchi et al., Reviews of Modern Physics (2013) 85-2
[2] F. Mirani, et al., Physical Review Applied 24.1 (2025): 014017
[3] I. Prencipe, et al., New Journal of Physics 23.9 (2021): 093015
[4] L. Sottili, et al. Applied Sciences 12.13 (2022): 6585
[5] F. Mirani et al., Science Advances (2021) 7-3
[6] P. Puyuelo-Valdes et al., Scientific Reports (2021) 11-9998
[7] M. Salvadori et al., Physical Review Applied (2024) 21-064020
[8] D. Margarone, et al. Quantum Beam Science 2.2 (2018): 8
[9] F. Gatti et al., IEEE Transaction on Instrumentation and Measurement (2024) 73-3536912
