A5030573022- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Particle physics theoretical and experimental studies
- Particle accelerators and beam dynamics
- Particle Detector Development and Performance
- Internet Traffic Analysis and Secure E-voting
- Dark Matter and Cosmic Phenomena
- Network Traffic and Congestion Control
- Advanced Graph Neural Networks
- Complex Network Analysis Techniques
- Laser Design and Applications
- Numerical Methods and Algorithms
- International Science and Diplomacy
- Surgical Sutures and Adhesives
- Graph Theory and Algorithms
- Network Security and Intrusion Detection
- Structural Analysis and Optimization
- High-Energy Particle Collisions Research
- Distributed and Parallel Computing Systems
- Network Packet Processing and Optimization
- Parallel Computing and Optimization Techniques
- Scientific Research and Discoveries
- Astrophysics and Cosmic Phenomena
- Laser-Plasma Interactions and Diagnostics
- Atomic and Subatomic Physics Research
European Organization for Nuclear Research
2019-2024
University of Naples Federico II
2024
Aristotle University of Thessaloniki
2022-2023
National Technical University of Athens
2020-2021
Hypothetical low-mass particles, such as axions, provide a compelling explanation for the dark matter in universe. Such particles are expected to emerge abundantly from hot interior of stars. To test this prediction, CERN Axion Solar Telescope (CAST) uses 9 T refurbished Large Hadron Collider magnet directed towards Sun. In strong magnetic field, solar axions can be converted X-ray photons which recorded by detectors. 2013–2015 run, thanks low-background detectors and new telescope,...
Network operators and researchers frequently use Internet measurement platforms (IMPs), such as RIPE Atlas, RIS, or RouteViews for, e.g., monitoring network performance, detecting routing events, topology discovery, route optimization. To interpret the results of their measurements avoid pitfalls wrong generalizations, users must understand a platform's limitations. this end, paper studies an important limitation IMPs, bias, which exists due to non-uniform deployment vantage points....
We report on a new search for solar chameleons with the CERN Axion Solar Telescope (CAST). A GridPix detector was used to soft X-ray photons in energy range from 200 eV 10 keV converted chameleons. No signiffcant excess over expected background has been observed data taken 2014 and 2015. set an improved limit chameleon photon coupling, $\beta_\gamma < 5.7\times10^{10}$ $1<\beta_\mathrm{m}<10^6$ at 95% C.L. improving our previous results by factor two first time reaching sensitivity below...
SixTrack is a single-particle tracking code for high-energy circular accelerators routinely used at CERN the Large Hadron Collider (LHC), its luminosity upgrade (HL-LHC), Future Circular (FCC) and Super Proton Synchrotron (SPS) simulations. The based on 6D symplectic engine, which optimized long-term simulations delivers fully reproducible results several platforms. It also includes multiple scattering engines beam–matter interaction studies, as well facilities to run integrated with...
Several transverse noise sources, such as power supply ripples, can potentially act an important limiting mechanism for the luminosity production of Large Hadron Collider (LHC) and its future High-Luminosity upgrade (HL-LHC). In presence non-linearities, depending on spectral components nature source, a increase diffusion particles in distribution through excitation sideband resonances vicinity ones driven by lattice non-linearities. For HL-LHC, due to reduction beam size Interaction Points...
Abstract SixTrack Version 5 is a major release that introduces new features, with improved integration of the existing ones, and extensive code restructuring. New features include dynamic-memory management, scattering-routine integration, initial-condition module, reviewed post-processing methods. Existing like on-line aperture checking Fluka-coupling are now enabled by default. Extensive performance regression tests have been developed deployed as part new-release generation. The tracking...
Abstract Operating at 6.5 TeV, the LHC surpassed expectations and delivered an average of 66 fb –1 integrated luminosity to two high experiments ATLAS CMS by end 2018. In order provide a continuous feedback machine coordination for further optimizing performance, automated tool monitoring main beam parameters configurations, has been devised extensively used. New features like coupling between planes effects noise, were added numerical model used since 2016 calculate luminosity. Estimates,...
Abstract Operation of the Large Hadron Collider (LHC) requires strong octupolar magnetic fields to suppress coherent beam instabilities. The amplitude detuning that is generated by these brings tune individual particles close harmful resonances, which are mostly driven themselves. In 2023, new optics were deployed in LHC at injection with optimized betatronic phase advances minimize resonances from without affecting detuning. This paper reports on design, commissioning, and lifetime...
Abstract The High Luminosity (HL-LHC) project aims to increase the integrated luminosity of CERN's Large Hadron Collider (LHC) by an order magnitude compared its initial design. This requires a large in bunch intensity and beam brightness first three LHC runs, hence poses serious collective-effects challenges, related particular electron cloud, instabilities from beam-coupling impedance, beam-beam effects. Here, we present associated constraints mitigation measures proposed achieve baseline...
Abstract The Large Hadron Collider (LHC) Long Shutdown 2 (2019–2021), following LHC Run 2, was primarily dedicated to the upgrade of Injectors but it included also a significant amount activities aimed at consolidation machine components, removal known limitations and initial upgrades in view High-Luminosity (HL-LHC) favour intensity ramp-up during 3 (2022–2025). An overview major modifications accelerator its systems is followed by summary results superconducting magnet training campaign...
In 2018 the world's first Crab Cavity (CC) experiments with protons were successfully performed, aiming to study CC effect on a proton beam and evaluate engineering challenges. Before commencement of these experiments, impact CCs their multipoles long term particle stability SPS was studied using dynamic aperture simulations. Furthermore, in order ensure luminosity performance LHC upgrade, High Luminosity (HL-LHC), limits stable motion also examined presence multipole errors, voltage errors...
The compensation of the long-range beam-beam interactions using DC wires is presently under study as an option for enhancing machine performance in frame High-Luminosity LHC project (HL-LHC). original idea dates back more than 15 years. After installation four wire prototypes 2018, a successful experimental campaign was performed during last months. setup and main results are reported this paper.
Harmonics of the mains frequency (50 Hz) have been systematically observed in transverse beam spectrum Large Hadron Collider (LHC) since start its operation form dipolar excitations. In presence strong non-linearities such as beam-beam interactions, many these power supply ripple tones reside vicinity betatron tune they can increase diffusion particles distribution, leading to proton losses and eventually a significant reduction lifetime. The aim this paper is determine whether 50~Hz...
Since the beginning of Large Hadron Collider (LHC) commissioning, spectral components at harmonics mains frequency (50 Hz) have been observed in transverse beam spectrum. This paper presents an overview most important observations, collected during latest physics operation LHC 2018, which clearly indicates that are result a real excitation rather than instrumental feature. Based on these findings, potential sources perturbation discussed and correlation with power supply ripple originating...
A group of Early-Career Researchers (ECRs) has been given a mandate from the European Committee for Future Accelerators (ECFA) to debate topics current Strategy Update (ESU) Particle Physics and summarise outcome in brief document [1]. full-day with 180 delegates was held at CERN, followed by survey collecting quantitative input. During debate, ECRs discussed future colliders terms physics prospects, their implications accelerator detector technology as well computing software. The...
The Internet is composed of networks, called Autonomous Systems (or, ASes), interconnected to each other, thus forming a large graph. While both the AS-graph known and there multitude data available for ASes (i.e., node attributes), research on applying graph machine learning (ML) methods has not attracted lot attention. In this work, we provide benchmarking framework aiming facilitate using graph-ML neural network (GNN) methods. Specifically, compile dataset with heterogeneous node/AS...