Antonino Picciotto

Thin film stress offers a scalable and contact free approach for inducing controlled and tunable bending in silicon crystals, with direct relevance for bent crystal channeling and related beam manipulation applications. In this work, stress evolution of silicon nitride films deposited by LPCVD and ICP-CVD, thermally grown silicon dioxide (SiO2) and titanium nitride (TiN) thin films deposited by reactive magnetron sputtering on silicon (Si) substrates is systematically investigated as a function of film thickness. Silicon nitride films exhibit an approximately linear stress-thickness dependence, leading to strong bending at small thicknesses, followed by gradual reduction in bending efficiency with increasing film thickness. Thermally grown SiO2 behaves as an approximately constant-stress system, resulting in a stable and predictable curvature response. In contrast, TiN films display exponential stress relaxation with thickness, enabling significant curvature even at small thicknesses. By combining experimentally calibrated stress-thickness relations with practical film thickness limits, this work establishes a predictive framework linking material choice, film thickness, and substrate geometry to achievable bending radii for representative channeling and beam manipulation applications.

In today’s scenario of science and technology, there is an increasing interest in cheap and scalable methods for the realization of materials such as silicon carbide (SiC), which are relevant for power electronics, radiation and particle detectors, and energy storage applications. In this work, a series of surface ion implantations of carbon ions were performed by the aid of 70 keV argon primary beam (dose =1 × 10^15 – 5 × 10^15 ions/cm^2 ) into a photoresist polymer layer (≈ 100 nm) deposited on a silicon wafer substrate to force a significant concentration of carbon atoms, even substitutional, and potentially create a silicon carbide (SiC) layer, on top of this substrate. To this end, the implantation conditions were optimized using Monte Carlo simulations to maximize carbon implantation efficiency. X-ray Photoelectron Spectroscopy (XPS) analysis of the treated samples confirmed the successful formation of substitutional carbon in silicon and verified the chemical stoichiometry. This approach can leverage the standard photolithography processes as well as focused ion beam technology for a broad range of applications.

The High Energy Rapid Modular Ensemble of Satellites (HERMES) instrument is a compact X-/gamma-ray spectrometer operating on board the 6U (11 kg) Space Industry–Responsive–Intelligent–Thermal (SpIRIT) CubeSat. The payload is particularly well suited for the observation of cosmic transients such as gamma-ray bursts (GRBs) and bright pulsars thanks to its unique broadband sensitivity from a few keV to a few MeV and temporal resolution down to half a microsecond. We report the detection of the ∼33 ms double-peaked pulse profile of the Crab Pulsar, obtained by considering the canonical Crab ephemerides as provided by the Jodrell Bank catalog. We collected approximately 5.7 × 10 ⁴ photons from 730 s of observations in the 3 keV–2 MeV energy band during a single operation, achieving a 5 σ pulse-profile significance in the 3–11.5 keV energy band with millisecond-scale binning. These results demonstrate that SpIRIT/HERMES can achieve millisecond timing accuracy at high energies and, thanks to its wide field of view and broad energy coverage, has the potential to contribute to GRB monitoring in the near future. Such capabilities were previously the domain of flagship observatories, underscoring the performance of the HERMES instrument even with its compact form factor.

Recent advances in ion diagnostics for laser-induced plasma experiments have improved system design and data analysis. Measuring charged particle emissions from laser-irradiated targets provides valuable insights into laser–matter interactions. Among real-time diagnostics, Time-of-Flight (TOF) detectors are reliable systems for analyzing particle beam properties such as kinetic energy and shot-to-shot reproducibility. Diamond-based detectors are ideal for TOF measurements due to their fast response time, radiation hardness, and low leakage current. However, TOF detectors lack particle discrimination. To overcome this, a Multi Filter Diamond Array (MFDA) was developed using six nominally identical single crystal diamond detectors paired with aluminum foils of different thicknesses to exploit particle stopping power differences. The MFDA was tested at the Prague Asterix Laser System during an experimental campaign in the framework of the FUSION project, and data analysis was performed. A cross-validation with other diagnostics, including a Thomson Parabola Spectrometer and CR-39 detectors, is also presented.

The Wide Field Monitor is one of the 4 state-of-the-art instruments onboard the enhanced X-ray Timing and Polarimetry mission, which will search for and observe neutron stars, magnetars and black holes to study matter under extreme conditions of density, gravity and magnetism. The wide-field cameras of the Wide Field Monitor are based on large-area silicon drift detectors. Such position-sensitive spectroscopic detectors, together with their front-end electronics, must pass a series of functional tests before proceeding with the mass production of the detector assemblies. This paper describes the test system developed to carry out such measurements, as well as reporting the results of the functional tests together with a preliminary characterisation of the performance of the detector assemblies.

Novel targets were implemented in the beam-driven (in-target) proton-boron fusion with beneficial characteristics (chemical composition and density) compared to the commonly used boron nitride. A fusion-generated alpha particle flux of up to ( 5 × 10 7 sr − 1 J − 1 ) was generated via the proton-boron fusion reactions when irradiating the targets with a moderate laser system ( 10 J , 800 fs , 10 19 W cm − 2 ). Normalized by laser energy, the alpha particle flux generated in this experiment is comparable with the highest alpha particle yields reported in the literature. We present experimental results with supporting simulations and calculations of the expected alpha particle yield.

In this work, a novel, silicon-based micro-electromechanical valve that includes a submicrometric orifice and can operate at pressure gradients of 1 bar was used to enhance sampling for gas chromatograph mass spectrometers. The valve is based on a membrane-in-membrane design and operates with thermomechanical actuation. It includes a pin to enable self-cleaning. Prototypes were fabricated and preliminary testing was performed.

An experimental platform for laser-driven ion (sub-MeV) acceleration and potential applications was commissioned at the HiLASE laser facility. The auxiliary beam of the Bivoj laser system operating at a GW level peak power (~10 J in 5–10 ns) and 1–10 Hz repetition rate enabled a stable production of high-current ion beams of multiple species (Al, Ti, Fe, Si, Cu, and Sn). The produced laser–plasma ion sources were fully characterized against the laser intensity on the target (10¹³–10¹⁵ W/cm²) by varying the laser energy, focal spot size, and pulse duration. The versatility and tuneability of such high-repetition-rate laser–plasma ion sources are of potential interest for user applications. Such a statistically accurate study was facilitated by the large amount of data acquired at the high repetition rate (1–10 Hz) provided by the Bivoj laser system.

An experimental platform for laser-driven ion (sub-MeV) acceleration and potential applications was recently commissioned at the HiLASE laser facility. The auxiliary beam of the Bivoj laser system operating at GW peak power (~10 J in 5-10 ns) and 1-10 Hz repetition rate enabled a sta-ble production of high-current ion beams of multiple species (Al, Ti, Fe, Si, Cu, Sn). The pro-duced laser-plasma ion sources were fully characterized against the laser intensity on target (1013-1015 W/cm2) by varying the laser energy, focal spot size, and pulse duration. This al-lowed to provide accurate scaling laws of the maximum ion energy for the different target ma-terials investigated. Such experimental scaling laws are presented for the first time in the inves-tigated laser intensity range and for ns-class laser pulses, and allow to provide a qualitative in-terpretation of the laser-plasma interaction underpinning physics, thus to tune the main features of the accelerated ion beams (energy, temperature, and current). Such a detailed study was facil-itated by the large amount of data acquired at high repetition rate (1-10 Hz) provided by the Bivoj laser system. The versatility and tuneability of such high-repetition-rate laser-plasma ion sources are of po-tential interest for multidisciplinary user applications.