Roxana Radu | Searcharxiv

arXiv2025

The Future of the AI Summit Series

This policy memo examines the evolution of the international AI Summit series, initiated at Bletchley Park in 2023 and continued through Seoul in 2024 and Paris in 2025, as a forum for cooperation on the governance of advanced artificial intelligence. It analyzes the factors underpinning the series' early successes and assesses challenges related to scope, participation, continuity, and institutional design. Drawing on comparisons with existing international governance models, the memo evaluates options for hosting arrangements, secretariat formats, participant selection, agenda setting, and meeting frequency. It proposes a set of design recommendations aimed at preserving the series' focus on advanced AI governance while balancing inclusivity, effectiveness, and long-term sustainability.

cs.CY↗

arXiv2018

Study of point- and cluster-defects in radiation-damaged silicon

Non-ionising energy loss of radiation produces point defects and defect clusters in silicon, which result in a signifcant degradation of sensor performance. In this contribution results from TSC (Thermally Stimulated Current) defect spectroscopy for silicon pad diodes irradiated by electrons to fluences of a few $10^{14}$ cm$^{-2}$ and energies between 3.5 and 27 MeV for isochronal annealing between 80 and 280°C, are presented. A method based on SRH (Shockley-Read-Hall) statistics is introduced, which assumes that the ionisation energy of the defects in a cluster depends on the fraction of occupied traps. The dfference of ionisation energy of an isolated point defect and a fully occupied cluster, $ΔE_a$, is extracted from the TSC data. For the VOi (vacancy-oxygen interstitial) defect $ΔE_a = 0$ is found, which cofirms that it is a point defect, and validates the method for point defects. For clusters made of deep acceptors the $ΔE_a$ values for different defects are determined after annealing at 80°C as a function of electron energy, and for the irradiation with 15 MeV electrons as a function of annealing temperature. For the irradiation with 3.5 MeV electrons the value $ΔE_a = 0$ is found, whereas for the electron energies of 6 to 27 MeV $ΔE_a > 0$. This agrees with the expected threshold of about 5 MeV for cluster formation by electrons. The $ΔE_a$ values determined as a function of annealing temperature show that the annealing rate is different for different defects. A naive diffusion model is used to estimate the temperature dependencies of the diffusion of the defects in the clusters.

physics.ins-det↗