Archivio della ricerca - Fondazione Bruno Kessler
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Rapid test device for the detection of SARS-COV-2 viruses and the relative antibody production
No full textExperimental Characterization of the Nova Asic for the Lem-X Mission Concept
No full textThe Lunar Electromagnetic Monitor in X-rays (LEM-X) is a proposed all-sky observatory for the continuous monitoring of astrophysical sources and the rapid follow-up of high-energy transients from the surface of the Moon in the 2−50keV band. It consists of several pairs of coded-aperture cameras arranged in a dome-like structure. Each camera features a focal plane composed of four independent Detector Assemblies (DAs), each built around a large-area linear Silicon Drift Detector capable of both spectral-timing measurements and imaging. To perform the readout of the sensor, each of the 768 anodes (arranged on two separate rows) is connected to the analog input of an Application Specific Integrated Circuit (ASIC), named NOVA, developed for the project in an effort to optimize the performance of the detector given the demanding constraints of inspace operation. The experimental characterization of the spectral capabilities of the NOVA ASIC was carried out on a prototype of the LEM-X DA. In it, a sensor having the same design as the LEM-X detector but only 64 readout anodes was coupled to two 32-channel NOVA ASICs. Anodewise X-ray spectra were acquired as a function of temperature and peaking time, yielding a median resolution of 163 eV at 5.89 keV at −20∘C, which is compatible with the instrument requirements
La guerra contadina a sud delle Alpi: i focolai trentini, in Il potere delle macchine: umanità, ambiente, tecnologia nel Trentino del Cinquecento
No full textLLM-Enriched Finite-State Chatbots for Mental Health Support: A Case Study on Self-Help+
No full textDigital mental health tools, such as chatbots, address the growing demand for psychological support but often lack dynamic, empathetic, and personalized interactions. This study evaluates the integration of Large Language Models into structured chatbots to enhance the delivery of the World Health Organization’s Self-Help+ intervention. A within-subject experiment with 44 participants compared a standard state-machine chatbot to a Large Language Model augmented version. Participants rated the chatbots using a specialized evaluation scale and provided qualitative feedback. The Large Language Model enriched the chatbot significantly; its integration improved emotional support, memory retention, and user satisfaction. Challenges included hallucinations, verbosity, and limited conversational flexibility due to the retainment of the finite-state structure. These findings highlight Large Language Models’ potential to improve digital mental health tools and that structured conversation approaches are perceived as a major drawback for users, even when interacting with Large Language Models. Future efforts should, therefore, address hallucination mitigation and explore multi-agent architectures to enhance adaptability and user experience
Material Characterization of 4H-SiC Using a Carbon Cap Protective Mask Before and After Al and P Ion Implantation: Effects on Surface Morphology
No full textHigh‐bandgap semiconductor materials such as silicon carbide (SiC) have recently gained significant attention due to their superior electrical, thermal, and mechanical properties compared to conventional semiconductors like silicon (Si) [1,2]. Dopant ion implantation is a key step in fabricating SiC power devices; however, it often induces substantial surface damage, and the high‐temperature annealing (>1600 °C) required for dopant activation can cause surface roughening and step bunching. This study examines the influence of amorphous carbon (a‐C) cap layer on the preservation of surface morphology during ion implantation and post annealing process in 4H‐SiC. Wafers were implanted with aluminum (Al) and phosphorus (P) ions at various energies and doses at 500 °C, using a‐C cap layers of 20 nm and 50 nm thickness applied either before implantation (pre‐cap) or after implantation (post‐cap). Post‐implantation annealing was carried out at 1700 °C to activate dopants.
Atomic Force Microscopy (AFM) was used to evaluate changes in surface roughness and morphology. The results demonstrate the role of carbon capping effectively suppresses surface degradation, minimizing roughness during high‐temperature annealing.
These findings highlight the dual role of carbon capping as a protective barrier and implantation mask, offering a practical approach to improving surface quality and dopant activation in 4H‐SiC device processing
Centri di colore in diamante: strumenti e tecniche per una fabbricazione flessibile
No full textI centri di colore nei semiconduttori rappresentano una delle piattaforme più promettenti nell’ambito delle tecnologie quantistiche di nuova generazione. Grazie alla loro capacità di emettere singoli fotoni, questi difetti puntuali consentono progressi significativi nel sensing quantistico, nella computazione e nelle comunicazioni su larga scala. Per integrarli efficacemente in dispositivi quantistici, è cruciale generare centri di colore in modo controllato in termini di densità e di posizionamento laterale all’interno della matrice cristallina.
Presso FBK disponiamo di laboratori in cui tecniche avanzate di nanofabbricazione si combinano con strumentazione ottica ad alte prestazioni.
Grazie alla tecnologia di Focused Ion Beam (FIB), siamo in grado di produrre difetti quantistici in semiconduttori a larga band gap con precisione laterale inferiore ai 100 nm, controllando sia la profondità tramite l’energia del fascio sia il numero di ioni impiantati, così da ottenere singoli emettitori.
A questo si aggiunge la possibilità di effettuare avanzate analisi ottiche attraverso l’utilizzo di un microscopio confocale per misure Raman/PL con sensibilità di singolo fotone, equipaggiato con un interferometro HBT per le misure di antibunching, che consente una caratterizzazione minuziosa dei centri di colore come sorgenti quantistiche a stato solido.
In questo lavoro saranno presentati i risultati ottenuti nella formazione di emettitori quantistici nel diamante basati su centri GeV− e SiV−, creati mediante l’impianto delle rispettive specie ioniche con il FIB, e la loro integrazione in strutture fotoniche come i nanopillars. L’impiego del FIB consente inoltre di realizzare regioni conduttive tramite la grafitizzazione del diamante, utili per creare strati conduttivi integrati o sepolti, necessari per pilotare elettricamente i centri colore o per ottenere elettrodi con buon contatto ohmico. Infine, saranno illustrati la realizzazione di centri NV poco profondi (shallow) mediante impianto broad-beam, particolarmente indicati per costruire sensori essendo prossimi alla superficie, e i progressi nello sviluppo di tecniche per la fabbricazione controllata di lamelle di diamante destinate alla nano-termometria quantistica
Baryon number violation: from nuclear matrix elements to BSM physics
No full textAbstract
Processes that violate baryon number, most notably proton decay and
n
n
̄
transitions, are promising probes of physics beyond the Standard Model (BSM) needed to understand the lack of antimatter in the Universe. To interpret current and forthcoming experimental limits, theory input from nuclear matrix elements to UV complete models enters. Thus, an interplay of experiment, effective field theory, lattice QCD, and BSM model building is required to develop strategies to accurately extract information from current and future data and maximize the impact and sensitivity of next-generation experiments. Here, we briefly summarize the main results and discussions from the workshop ‘INT-25-91W: Baryon Number Violation: From Nuclear Matrix Elements to BSM Physics,’ held at the Institute for Nuclear Theory, University of Washington, Seattle, WA, 13–17 January 2025
Humanity's Last Exam
No full textBenchmarks are important tools for tracking the rapid advancements in large
language model (LLM) capabilities. However, benchmarks are not keeping pace in
difficulty: LLMs now achieve over 90\% accuracy on popular benchmarks like
MMLU, limiting informed measurement of state-of-the-art LLM capabilities. In
response, we introduce Humanity's Last Exam (HLE), a multi-modal benchmark at
the frontier of human knowledge, designed to be the final closed-ended academic
benchmark of its kind with broad subject coverage. HLE consists of 2,700
questions across dozens of subjects, including mathematics, humanities, and the
natural sciences. HLE is developed globally by subject-matter experts and
consists of multiple-choice and short-answer questions suitable for automated
grading. Each question has a known solution that is unambiguous and easily
verifiable, but cannot be quickly answered via internet retrieval.
State-of-the-art LLMs demonstrate low accuracy and calibration on HLE,
highlighting a significant gap between current LLM capabilities and the expert
human frontier on closed-ended academic questions. To inform research and
policymaking upon a clear understanding of model capabilities, we publicly
release HLE at https://lastexam.ai
New developments in 3D-trench electrode sensors
No full textFuture high-luminosity hadron collider experiments feature unprecedented levels of event pile-up and extreme radiation environments, calling for sensors capable of 4D tracking, even after significant radiation damage. To this purpose, 3D sensors represent a viable solution, since they provide excellent radiation tolerance and very good temporal resolution. In particular, owing to the uniform electric field and weighting field distributions, 3D-trench electrode sensors from the INFN TIMESPOT project have shown a temporal resolution of ∼10 ps after irradiation fluences up to 1×1017 1-Mev neq/cm2. In spite of the excellent performance of these sensors, 3D-trench pixel technology is not yet fully established and the fabrication yield is not yet adequate for the production of large size pixel sensors. To improve the potential of the 3D-trench concept for large-area sensors, a new batch of sensors was designed at the University of Trento and fabricated at FBK, as part of the AIDAinnova project. Besides introducing some process improvements, this batch includes two different sensor variants: the standard one with continuous ohmic trenches, and a modified one with dashed ohmic trenches. On-wafer electrical test results show that most of the sensors have low leakage current and high breakdown voltage. Moreover, the fabrication yield for the new design variant is higher than that of the standard design
Measurement of ion stopping power in the framework of nuclear reactions in plasmas
Get PDFThe study of nuclear reactions and interactions in plasmas has recently assumed great importance because of its connection with processes such as laser-driven ion acceleration and nuclear fusion for massive energy production. In fact, the extremely high electron densities established in the plasma bring to different behaviour of charged particles with respect to that observed when a stable beam impinges on a solid target.
Ion stopping power in cold matter is relatively well known and has been characterized with the help of a large set of experimental data and theoretical studies; on the contrary a lot of open questions remain when it comes to ions stopping in a plasma, especially in the energy domain where the projectile ion velocity approaches that of free plasma electrons. The main aim of this work is a systematic and careful measurement of stopping power for several ions versus plasma parameters, especially in the region of thermal velocities, where the energy deposition should depend strongly on plasma temperature, density and ionization fraction.
The plasma will be generated under vacuum, by interaction of a laser beam with a solid target. Plasma plume will be characterized in temperature and density by optical and X-ray diagnostics; simultaneously the energy loss will be measured for an ion microbeam crossing the plume.
This contribution provides an overview of the experimental technique and the results obtained during first tests for the characterization of experimental apparatus