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1. The n_TOF facility at CERN

Author

Tagliente G., Aberle O., Alcayne V., Amaducci S., Andrzejewski J., Babiano-Suarez V., Bacak M., Balibrea Correa J., Bernardes A.P., Berthoumieux E., Beyer R., Boromiza M., Bosnar D., Caamaño M., Calviño F., Calviani M., Cano-Ott D., Casanovas A., Castelluccio D.M., Cerutti F., Cescutti G., Chasapoglou S., Chiaveri E., Claps G., Colombetti P., Colonna N., Console Camprini P., Cortés G., Cortés-Giraldo M.A., Cosentino L., Cristallo S., Dellmann S., Diacono D., Di Castro M., Diakaki M., Dietz M., Domingo-Pardo C., Dressler R., Dupont E., Durán I., Eleme Z., Eslami M., Fargier S., Fernández-Domínguez B., Finocchiaro P., Furman V., Gandhi A., García-Infantes F., Gawlik-Ramięga A., Gervino G., Gilardoni S., González-Romero E., Goula S., Griesmayer E., Guerrero C., Gunsing F., Gustavino C., Heyse J., Hillman W., Jenkins D. G., Jericha E., Junghans A., Kadi Y., Kaperoni K., Kokkoris M., Koll D., Kopatch Y., Krtička M., Kyritsis N., Ladarescu I., Lederer-Woods C., Lerendegui-Marco J., Lerner G., Manna A., Martínez T., Masi A., Massimi C., Mastinu P., Mastromarco M., Maugeri E.A., Mazzone A., Mendoza E., Mengoni A., Michalopoulou V., Milazzo P.M., Mucciola R., Musacchio-Gonzalez E., Musumarra A., Negret A., Pérez de Rada A., Pérez-Maroto P., Patronis N., Pavón-Rodríguez J.A., Pellegriti M.G., Perkowski J., Petrone C., Piersanti L., Pirovano E., Plaza del Olmo J., Pomp S., Porras I., Praena J., Quesada J. M., Reifarth R., Rochman D., Romanets Y., Rooney A., Rubbia C., Sánchez-Caballero A., Sabaté-Gilarte M., Scarpa D., Schillebeeckx P., Schumann D., Smith A.G., Sosnin N.V., Spelta M., Stamati M.E., Tamburrino A., Tarifeño-Saldivia A., Tarrío D., Torres-Sánchez P., Tosi S., Tsiledakis G., Valenta S., Vaz P., Vecchio G., Vescovi D., Vlachoudis V., Vlastou R., Wallner A., Weiss C., Woods P.J., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The neutron Time-of-Flight (TOF) research facility at CERN, n_TOF, has been a pioneering platform for neutron cross-section measurements since its inception in 2001. It boasts three distinct experimental areas, each tailored to address a specific range of neutron energies. This paper delves into the intricacies of the n_TOF facility, including its recent upgrade during the Long Shutdown 2 (LS2) at CERN. Additionally, it highlights the key characteristics of the detectors employed for capture and fission cross-section measurements, paving the way for future research endeavors.

Published
2024
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2. Description and outlook of the 50,53Cr(n,γ) cross section measurement at n_TOF and HiSPANoS

Author

Pérez-Maroto P., Guerrero C., Casanovas A., Fernández B., Aberle O., Alcayne V., Altieri S., Amaducci S., Andrzejewski J., Babiano-Suarez V., Bacak M., Balibrea Correa J., Beltrami C., Bennett S., Bernardes A. P., Berthoumieux E., Beyer R., Boromiza M., Bosnar D., Caamaño M., Calviño F., Calviani M., Cano-Ott D., Castelluccio D. M., Cerutti F., Cescutti G., Chasapoglou S., Chiaveri E., Colombetti P., Colonna N., Console Camprini P., Cortés G., Cortés-Giraldo M. A., Cosentino L., Cristallo S., Dellmann S., Di Castro M., Di Maria S., Diakaki M., Dietz M., Domingo-Pardo C., Dressler R., Dupont E., Durán I., Eleme Z., Fargier S., Fernández-Domínguez B., Finocchiaro P., Fiore S., Furman V., García-Infantes F., Gawlik-Ramięga A., Gervino G., Gilardoni S., González-Romero E., Gunsing F., Gustavino C., Heyse J., Hillman W., Jenkins D. G., Jericha E., Junghans A., Kadi Y., Kaperoni K., Kaur G., Kimura A., Knapová I., Kokkoris M., Kopatch Y., Krtička M., Kyritsis N., Ladarescu I., Lederer-Woods C., Lerendegui-Marco J., Lerner G., Manna A., Martínez T., Masi A., Massimi C., Mastinu P., Mastromarco M., Maugeri E. A., Mazzone A., Mendoza E., Mengoni A., Michalopoulou V., Milazzo P. M., Mucciola R., Murtas F., Musacchio-Gonzalez E., Musumarra A., Negret A., Pérez de Rada A., Patronis N., Pavón-Rodríguez J. A., Pellegriti M. G., Perkowski J., Petrone C., Pirovano E., Plaza del Olmo J., Pomp S., Porras I., Praena J., Quesada J. M., Reifarth R., Rochman D., Romanets Y., Rubbia C., Sánchez-Caballero A., Sabaté-Gilarte M., Schillebeeckx P., Schumann D., Sekhar A., Smith A. G., Sosnin N. V., Stamati M. E., Sturniolo A., Tagliente G., Tarifeño-Saldivia A., Tarrío D., Torres-Sánchez P., Vagena E., Valenta S., Variale V., Vaz P., Vecchio G., Vescovi D., Vlachoudis V., Vlastou R., Wallner A., Woods P. J., Wright T., Zarrella R., and Žugec P.

Subjects
Physics, QC1-999
Abstract

Chromium is a very relevant element regarding criticality safety in nuclear reactors because of its presence in stainless steel, an important structural material. Currently, there are serious discrepancies between the different evaluations regarding the neutron capture cross sections of 50Cr and 53Cr, most probably related to the difficulty of reducing and then estimating the very large neutron scattering effects on the shape of the resonances. In this context, there is a recent entry in the Nuclear Energy Agency (NEA) High Priority Request List (HPRL) to measure these reactions between 1 and 100 keV with an accuracy of 8-10%. In response to this request, we have performed a time-of-flight experiment at CERN n_TOF (Switzerland) and a complementary activation experimenton 50Crat30and90keVatCNAHiSPANoS(Spain).Theexperiments are presented herein, together with a discussion on the quality of the preliminary data and the results to be expected.

Published
2024
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3. Experimental setup of the 239Pu neutron capture and fission cross-section measurements at n_TOF, CERN

Author

Sanchez-Caballero Adrian, Alcayne Victor, Andrzejewski Józef, Cano-Ott Daniel, Cardinaels Thomas, Dries Peter, Gawlik-Ramiega Aleksandra, González-Romero Enrique, Heyse Jan, Leinders Gregory, Martínez Trinitario, Mendoza Emilio, Moens Andre, Pérez de Rada Alberto, Perkowski Jarosław, Plompen Arjan, Paradela Carlos, Schillebeeckx Peter, Sibbens Goedele, Van Hecke Karen, Vanaken Koen, Vanleeuw David, Verguts Ken, Verwerft Marc, Wynants Ruud, Aberle Oliver, Altieri Saverio, Amaducci Simone, Babiano-Suarez Victor, Bacak Michael, Balibrea Correa Javier, Beltrami Chiara, Bennett Samuel, Bernardes Ana-Paula, Berthoumieux Eric, Beyer Roland, Boromiza Marian, Bosnar Damir, Caamaño Manuel, Calviño Francisco, Calviani Marco, Casanovas Adria, Castelluccio Donato, Cerutti Francesco, Cescutti Gabriele, Chasapoglou Sotirios, Chiaveri Enrico, Colombetti Paolo, Colonna Nicola, Console Camprini Patrizio, Cortés Guillem, Cortés-Giraldo Miguel, Cosentino Luigi, Cristallo Sergio, Dellmann, Di Castro Mario, Di Maria Salvatore, Diakaki Maria, Dietz Mirco, Domingo-Pardo César, Dressler Rugard, Dupont Emmeric, Durán Ignacio, Eleme Zinovia, Fargier Sylvain, Fernández Begoña, Fernández-Domínguez Beatriz, Finocchiaro Paolo, Fiore Salvatore, Furman Valter, García-Infantes Francisco, Gervino Gianpiero, Gilardoni Simone, Guerrero Carlos, Gunsing Frank, Gustavino Carlo, Hillman William, Jenkins David, Jericha Erwin, Junghans Arnd, Kadi Yacine, Kaperoni Kalliopi, Kaur Gurpreet, Kimura Atsushi, Knapová Ingrid, Kokkoris Michael, Kopatch Yury, Krtička Milan, Kyritsis Nikolaos, Ladarescu Ion, Lederer-Woods Claudia, Lerendegui-Marco Jorge, Lerner Giuseppe, Manna Alice, Masi Alessandro, Massimi Cristian, Mastinu Pierfrancesco, Mastromarco Mario, Maugeri Emilio-Andrea, Mazzone Annamaria, Mengoni Alberto, Michalopoulou Veatriki, Milazzo Paolo, Mucciola Riccardo, Murtas Fabrizio, Musacchio-Gonzalez Elizabeth, Musumarra Agatino, Negret Alexandru, Pérez-Maroto Pablo, Patronis Nikolas, Pavón-Rodríguez José-Antonio, Pellegriti Maria, Petrone Cristina, Pirovano Elisa, Plaza del Olmo Julio, Pomp Stephan, Porras Ignacio, Praena Javier, Quesada José-Manuel, Reifarth René, Rochman Dimitri, Romanets Yuriy, Rubbia Carlo, Sabaté-Gilarte Marta, Schumann Dorothea, Sekhar Adhitya, Smith Gavin, Sosnin Nikolay, Stamati Maria-Elisso, Sturniolo Alessandro, Tagliente Giuseppe, Tarifeño-Saldivia Ariel, Tarrío Diego, Torres-Sánchez Pablo, Vagena, Valenta Stanislav, Variale Vincenzo, Vaz Pedro, Vecchio Gianfranco, Vescovi Diego, Vlachoudis Vasilis, Vlastou Rosa, Wallner Anton, Woods Philip-John, Wright Tobias, Zarrella Roberto, and Žugec Petar

Subjects
Physics, QC1-999
Abstract

The experimental setup of the new measurement of 239Pu fission and capture cross-section in the n_TOF time-of-flight facility at CERN is presented. The measurement aims to address the needs and demands of nuclear data users. The experiment incorporates an innovative fast Fission Fragment Detector and the n_TOF Total Absorption Calorimeter, enabling the implementation of the fission tagging technique. Preliminary results exhibit the robust performance of the detector systems, along with the high quality of the new 239Pu samples. These samples were exclusively produced for this measurement by the European Commission’s Joint Research Centre in Geel.

Published
2024
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4. Hyperspectral Imaging—A Novel Tool to Assess Tissue Perfusion and Oxygenation in Esophageal Anastomoses

Author

Vaz Pimentel Vaz Pimentel, Merten Merten, Gosemann Gosemann, Gockel Gockel, Jansen-Winkeln Jansen-Winkeln, Mayer Mayer, and Lacher Lacher

Subjects
perfusion, hyperspectral imaging, esophageal atresia, anastomotic stricture, anastomotic leakage, Pediatrics, RJ1-570, Surgery, RD1-811
Abstract

Anastomotic stricture and leakage are common complications after repair of esophageal atresia (EA). A compromised perfusion of the anastomosis is a contributing factor. Hyperspectral imaging (HSI) is an ultrashort noninvasive method to measure tissue perfusion. We present two cases of with tracheoesophageal fistula (TEF)/EA repair, in whom we applied HSI: the first patient was a newborn with EA type C who underwent open TEF repair. The second one had an EA type A and cervical esophagostomy, in whom we performed gastric transposition. In both patients, HSI confirmed a good tissue perfusion of the later anastomosis. The postoperative course was uneventful and both patients are on full enteral feeds. We conclude that HSI is a safe and noninvasive tool that allows near real-time assessment of tissue perfusion and can contribute to the identification of the optimal anastomotic region during pediatric esophageal surgery.

Published
2023
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5. The Perceptions of Software Engineers Concerning the Utilization of Bots in the OSS Development Process: An Exploratory Survey

Author

Manso, Danyellias Vaz de Lima, Neto, Valdemar Vicente Graciano, and Kassab, Mohamad

Subjects
Computer Science - Software Engineering
Abstract

Software bots, extensively adopted by Open Source Software (OSS) projects, support developers across several activities, from automating predefined tasks to generating code that aids software engineers. However, with the growing prominence of bots, questions have emerged regarding the extension to which they truly assist or hinder software engineers in their routine tasks. To address this, an exploratory survey was conducted with 37 software engineers to gather insights into their views on the use of bots within the software development process. The findings suggest that bots are present across multiple phases of the software development lifecycle, providing daily support to professionals by enhancing productivity and facilitating task automation. Respondents stated that current bots are not sufficiently intelligent and raised new challenges and enhancements to aid bot designers in developing additional functionalities and integrations., Comment: 6 pages, 6 figures, 3 tables

Published
2024

6. The impact of disk-locking on convective turnover times of low-mass pre-main sequence and main sequence stars

Author

Landin, N. R., Mendes, L. T. S., Vaz, L. P. R., and Alencar, S. H. P.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

The impact of disk-locking on the stellar properties related to magnetic activity from the theoretical point of view is investigated. We use the ATON stellar evolution code to calculate theoretical values of convective turnover times ($\tau_{\rm c}$) and Rossby numbers ($Ro$, the ratio between rotation periods and $\tau_{\rm c}$) for pre-main sequence (pre-MS) and main sequence (MS) stars. We investigate how $\tau_{\rm c}$ varies with the initial rotation period and with the disk lifetime, using angular momentum conserving models and models simulating the disk-locking mechanism. In the latter case, the angular velocity is kept constant, during a given locking time, to mimic the magnetic locking effects of a circumstellar disk. The local convective turnover times generated with disk-locking models are shorter than those obtained with angular momentum conserving models. The differences are smaller in the early pre-MS, increase with stellar age and become more accentuated for stars with $M$$\geq$$1 {\rm M}_{\odot}$ and ages greater than 100 Myr. Our new values of $\tau_{\rm c}$ were used to estimate $Ro$ for a sample of stars selected from the literature in order to investigate the rotation-activity relationship. We fit the data with a two-part power-law function and find the best fitting parameters of this relation. The differences we found between both sets of models suggest that the star's disk-locking phase properties affect its Rossby number and its position in the rotation-activity diagram. Our results indicate that the dynamo efficiency is lower for stars that had undergone longer disk-locking phases., Comment: 12 pages, 9 figures. To be published in Astronomy & Astrophysics Main Jounal

Published
2024

7. Studying Binary Systems in Omega Centauri with MUSE. I. Detection of Spectroscopic Binaries

Author

Wragg, F., Kamann, S., Saracino, S., Latour, M., Dreizler, S., Martens, S., Seth, A., Vaz, D., and van de Ven, G.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

NGC 5139 ($\omega$ Cen), is the closest candidate of a Nuclear Star Cluster that has been stripped of its host galaxy in the Milky Way. Despite extensive studies through the last decades, many open questions about the cluster remain, including the properties of the binary population. In this study we use MUSE multi-epoch spectroscopy to identify binary systems in $\omega$ Cen. The observations span 8 years, with a total of 312 248 radial velocity measurements for 37 225 stars. Following the removal of known photometric variables, we identify 275 stars that show RV variations, corresponding to a discovery fraction of 1.4$\pm$0.1%. Using dedicated simulations, we find that our data is sensitive to 70$\pm$10% of the binaries expected in the sample, resulting in a completeness-corrected binary fraction of 2.1$\pm$0.4% in the central region of $\omega$ Cen. We find similar binary fractions for all stellar evolutionary stages covered by our data, the only notable exception being the blue straggler stars, which show an enhanced binary fraction. We also find no distinct correlation with distance from the cluster centre, indicating a limited amount of mass segregation within the half-light radius of $\omega$ Cen., Comment: 13 pages, 9 figures, 1 Table; Published by Monthly Notices of the Royal Astronomical Society (MNRAS)

Published
2024
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8. X-ray Single-Pixel Imaging with MPGD-based detectors

Author

Simões, M., Vaz, P., and Cortez, A. F. V.

Subjects
Physics - Instrumentation and Detectors
Abstract

X-ray imaging is an invaluable tool for noninvasive analysis in many fields ranging from basic science to medicine and security. The development of low-dose large area imaging solutions still represents an important challenge for various applications. One solution to the imaging of large areas lies in the development of novel computational imaging systems that can overcome the limitations imposed by hardware, relying instead on numerical processing power. The single-pixel detector, depending on the application, may offer a competitive edge over conventional cameras (being a cheaper alternative to the multi-pixelated solutions). In addition, the single-pixel detector can be used to achieve improved detection efficiency, faster timing response, and good spatial resolution with low radiation dose. Moreover, this technique enables detectors to image through diffuse mediums, increasing the image quality at significant depths, solving the depth penetration issues of other imaging methods. In this work, we explore the application of single-pixel imaging techniques to produce two-dimensional images with high temporal resolution (only if the process is reproducible and the conditions are static), using only a single detector (bucket detector). The setup, based on the application of Hadamard patterns, showed promising results, proving the ability of the system to acquire images using thin PLA based masks (up to 5 mm thickness). Both simulation, using GEANT 4, and experimental setup, based on a time projection chamber (TPC), used in this work to demonstrate this technique will be reported here along with the first results., Comment: 17 pages, 13 figures and 3 tables, paper

Published
2024

9. Parameterized Spanning Tree Congestion

Author

Lampis, Michael, Mitsou, Valia, Nemery, Edouard, Otachi, Yota, Vasilakis, Manolis, and Vaz, Daniel

Subjects
Computer Science - Data Structures and Algorithms, Computer Science - Computational Complexity
Abstract

In this paper we study the Spanning Tree Congestion problem, where we are given a graph $G=(V,E)$ and are asked to find a spanning tree $T$ of minimum maximum congestion. Here, the congestion of an edge $e\in T$ is the number of edges $uv\in E$ such that the (unique) path from $u$ to $v$ in $T$ traverses $e$. We consider this well-studied NP-hard problem from the point of view of (structural) parameterized complexity and obtain the following results. We resolve a natural open problem by showing that Spanning Tree Congestion is not FPT parameterized by treewidth (under standard assumptions). More strongly, we present a generic reduction which applies to (almost) any parameter of the form ``vertex-deletion distance to class $\mathcal{C}$'', thus obtaining W[1]-hardness for parameters more restricted than treewidth, including tree-depth plus feedback vertex set, or incomparable to treewidth, such as twin cover. Via a slight tweak of the same reduction we also show that the problem is NP-complete on graphs of modular-width $4$. Even though it is known that Spanning Tree Congestion remains NP-hard on instances with only one vertex of unbounded degree, it is currently open whether the problem remains hard on bounded-degree graphs. We resolve this question by showing NP-hardness on graphs of maximum degree 8. Complementing the problem's W[1]-hardness for treewidth..., Comment: Abstract cropped to meet arXiv's requirements

Published
2024

10. Tuning the MAPS Adaptive Secondary Mirror: Actuator Control, PID Tuning, Power Spectra and Failure Diagnosis

Author

Johnson, Jess A., Vaz, Amali, Montoya, Manny, Morzinski, Katie M., Patience, Jennifer, Sivanandam, Suresh, Brusa, Guido, Durney, Olivier, Gardner, Andrew, Guyon, Olivier, Harrison, Lori, Jones, Ron, Leisenring, Jarron, Males, Jared, Payan, Bianca, Perez, Lauren, Rotman, Yoav, Taylor, Jacob, Vargas, Dan, and West, Grant

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The MMT Adaptive optics exoPlanet characterization System (MAPS) is currently in its engineering phase, operating on-sky at the MMT Telescope on Mt. Hopkins in southern Arizona. The MAPS Adaptive Secondary Mirror's actuators are controlled by a closed loop modified PID control law and an open loop feed-forward law, which in combination allows for faster actuator response time. An essential element of achieving the secondary's performance goals involves the process of PID gain tuning. To start, we briefly discuss the design of the MAPS ASM and its actuators. We then describe the actuator positional control system and control law. Next, we discuss a few of the issues that make ASM tuning difficult. We then outline our initial attempts at tuning the actuator controllers and discuss the use of actuator positional power spectra for both tuning and determining the health and failure states of individual actuators. We conclude by presenting the results of our latest round of tuning configuration trials, which have been successful at decreasing mirror latency, increasing operational mirror modes and improving image PSF., Comment: To be published in Proceedings of SPIE, Optics and Photonics 2024. 24 pages, 16 figures, 5 tables. Lead Author, J. Johnson. Second Lead Author, A. Vaz. Project P.I., K. Morzinski. Project Second P.I.s, J. Patience and S. Sivanandam, Project Manager, M. Montoya

Published
2024

11. Evaluation 2-Functors for Kac-Moody 2-Categories of Type A2

Author

Mackaay, Marco, Macpherson, James, and Vaz, Pedro

Subjects
Mathematics - Quantum Algebra, Mathematics - Category Theory, 17B67, 20G42
Abstract

We construct a 2-functor from the Kac-Moody 2-category for the extended quantum affine sl(3) to the homotopy 2-category of bounded chain complexes with values in the Kac-Moody 2-category for quantum gl(3), categorifying the evaluation map between the corresponding quantum Kac-Moody algebras., Comment: 32 pages, lots of figures, comments welcome. V2: Corrected a set of sign errors and accordingly slightly altered main proof

Published
2024

12. Exact solution for a discrete-time SIR model

Author

Lemos-Silva, Márcia, Vaz, Sandra, and Torres, Delfim F. M.

Subjects
Mathematics - Dynamical Systems, Physics - Physics and Society, Quantitative Biology - Populations and Evolution, 65L10, 65L12, 39A30, 92-10
Abstract

We propose a nonstandard finite difference scheme for the Susceptible-Infected-Removed (SIR) continuous model. We prove that our discretized system is dynamically consistent with its continuous counterpart and we derive its exact solution. We end with the analysis of the long-term behavior of susceptible, infected and removed individuals, illustrating our results with examples. In contrast with the SIR discrete-time model available in the literature, our new model is simultaneously mathematically and biologically sound., Comment: This is a preprint published Open Access in 'Applied Numerical Mathematics' [https://doi.org/10.1016/j.apnum.2024.09.014]

Published
2024
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13. Stability analysis and optimal control of the logistic equation

Author

Lemos-Silva, Márcia, Vaz, Sandra, and Torres, Delfim F. M.

Subjects
Mathematics - Optimization and Control, 34D23, 34N05, 49K05
Abstract

We consider the unexploited/exploited logistic equation and study the stability of equilibrium points through Lyapunov functions. Then, we apply first and second order optimality conditions for the optimal control of the total biomass yield. Finally, we note that the time-scale logistic equation present in the literature lacks biological significance and we propose a new version of a dynamic logistic equation, valid on an arbitrary time scale, for which any trajectory of the system, beginning with a positive initial condition, remains nonnegative., Comment: Accepted 30-Aug-2024; 20 pages, 5 figures

Published
2024

14. Exploring Foundation Models for Synthetic Medical Imaging: A Study on Chest X-Rays and Fine-Tuning Techniques

Author

da Silva, Davide Clode, Bernardes, Marina Musse, Ceretta, Nathalia Giacomini, de Souza, Gabriel Vaz, Silva, Gabriel Fonseca, Bordini, Rafael Heitor, and Musse, Soraia Raupp

Subjects
Electrical Engineering and Systems Science - Image and Video Processing, Computer Science - Computer Vision and Pattern Recognition, Computer Science - Graphics
Abstract

Machine learning has significantly advanced healthcare by aiding in disease prevention and treatment identification. However, accessing patient data can be challenging due to privacy concerns and strict regulations. Generating synthetic, realistic data offers a potential solution for overcoming these limitations, and recent studies suggest that fine-tuning foundation models can produce such data effectively. In this study, we explore the potential of foundation models for generating realistic medical images, particularly chest x-rays, and assess how their performance improves with fine-tuning. We propose using a Latent Diffusion Model, starting with a pre-trained foundation model and refining it through various configurations. Additionally, we performed experiments with input from a medical professional to assess the realism of the images produced by each trained model.

Published
2024

15. On Hecke and asymptotic categories for complex reflection groups

Author

Lacabanne, Abel, Tubbenhauer, Daniel, and Vaz, Pedro

Subjects
Mathematics - Representation Theory, Mathematics - Category Theory, Mathematics - Quantum Algebra, Primary: 17B37, 20C08, Secondary: 18M15, 20F55
Abstract

Generalizing the dihedral picture for G(M,M,2), we construct Hecke algebras (and categories) and asymptotic counterparts. We think of these as associated with the complex reflection group G(M,M,N)., Comment: 35 pages, many figures, comments welcome

Published
2024

16. Dietary Assessment Methods Applied in Clinical and Epidemiological Studies in Children and Adolescents with Autism Spectrum Disorder: A Systematic Review

Author

Eduarda de Souza Silva, Kamila Castro, Sandra Costa Valle, and Juliana dos Santos Vaz

Abstract

We conducted a systematic review of the literature to evaluate the quality of the dietary data and the methods used to obtain them in studies with children and adolescents with ASD. The search of PsycINFO, PubMed, SciELO, and Web of Science using SPIDER strategy retrieved 1975 studies. Data on dietary intake assessment methodologies were extracted. Eighty-nine studies were included. Food records and food frequency questionnaires were the most frequent dietary assessment methods. Overall, studies presented a low quality score. Most of them did not report dietary assessment of bias, description of dietary method application, validity, sensitivity analyses, and statistical adjustments. Future studies must improve the application of dietary assessment methods to advance scientific evidence related to nutrition in ASD.

Published
2024
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17. Observation and characterisation of trapped electron modes in Wendelstein 7-X

Author

Krämer-Flecken, A., Proll, J. H. E., Weir, G., Costello, P., Fuchert, G., Geiger, J., Heuraux, S., Knieps, A., Langenberg, A., Mendes, S. Vaz, Pablant, N., Pasch, E., Rahbarnia, K., Sabot, R., Salazar, L., Smith, H. M., Thomsen, H., Windisch, T., Xiang, H. M., and W7-X-team, the

Subjects
Physics - Plasma Physics
Abstract

In the past, quasi coherent modes were reported for nearly all tokamaks. The general definition describes modes as quasi coherent when the magnitude squared coherence is in the range of \SIrange{0.3}{0.6}{}. Quasi coherent modes are observed in the plasma core as well as in the plasma edge and can have quite different physical origins. The one in the core are observed in plasmas with low collisionality, where the electron temperature exceeds the ion temperature in the plasma core. This is the case for electron cyclotron heating in general. The origin of these modes are electrons trapped within a magnetic mirror, as reported in the past from various fusion devices. The so-called trapped-electron modes (TEMs) belong to drift wave instabilities and can be destabilized by electron-temperature gradients in the plasma core. From the diagnostic point of view, quasi coherent modes appear as fluctuations in electron density and temperature. Therefore, the microwave reflectometer is very well suited to monitor these modes. This paper describes experiments, conducted at the Wendelstein 7-X stellarator (W7-X), which aim at detecting quasi coherent modes at low wave numbers. A Poloidal Correlation Reflectometer (PCR) installed at W7-X, is able to measure low wave numbers ($k_\perp\le 3.5$ cm$^{-1}$). For different magnetic configurations and plasma parameters, broad quasi-coherent structures are observed in the coherence spectra. From the analysis of the rotation and the poloidal structure, these quasi coherent (QC) modes show the properties of electron-temperature-gradient driven TEMs. A linear relation between the mode velocity and the rotation frequency is found. The relation is uniform and confirms the nature of QC-mode observation as TEM in tokamaks, too.

Published
2024

18. ESCAPE: Efficient Synthesis of Calibrations for Adaptive optics through Pseudo-synthetic and Empirical methods

Author

Taylor, Jacob, Swanson, Robin, Levesque, Parker, Lamb, Masen, Vaz, Amali, Montoya, Manny, Gardner, Andrew, Morzinski, Katie M., and Sivanandam, Suresh

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

With the commissioning of the refurbished adaptive secondary mirror (ASM) for the 6.5-meter MMT Observatory under way, special consideration had to be made to properly calibrate the mirror response functions to generate an interaction matrix (IM). The commissioning of the ASM is part of the MMT Adaptive optics exoPlanet characterization System (MAPS) upgrade the observatory's legacy adaptive optics (AO) system. Unlike most AO systems, MAPS employs a convex ASM which prevents the introduction of a calibration source capable of simultaneously illuminating its ASM and wavefront sensor (WFS). This makes calibration of the AO system a significant hurdle in commissioning. To address this, we have employed a hybrid calibration strategy we call the Efficient Synthesis of Calibrations for Adaptive Optics through Pseudo-synthetic and Empirical methods (ESCAPE). ESCAPE combines the DO-CRIME on-sky calibration method with the SPRINT method for computing pseudo-synthetic calibration matrices. To monitor quasi-static system change, the ESCAPE methodology rapidly and continuously generates pseudo-synthetic calibration matrices using continual empirical feedback in either open or closed-loop. In addition, by measuring the current IM in the background while in close-loop, we are also able to measure the optical gains for pyramid wavefront sensor (PyWFS) systems. In this paper, we will provide the mathematical foundation of the ESCAPE calibration strategy and on-sky results from its application in calibrating the MMT Observatory's ASM. Additionally, we will showcase the validation of our approach from our AO testbed and share preliminary on-sky results from MMT., Comment: 16 pages, 9 figures, Submission to SPIE Adaptive Optics Systems IX

Published
2024

19. Two-row Delta Springer varieties

Author

Lacabanne, Abel, Vaz, Pedro, and Wilbert, Arik

Subjects
Mathematics - Representation Theory, Mathematics - Combinatorics, Mathematics - Quantum Algebra, Primary: 14M15, Secondary: 05E10, 20C08
Abstract

We study the geometry and topology of $\Delta$-Springer varieties associated with two-row partitions. These varieties were introduced in recent work by Griffin-Levinson-Woo to give a geometric realization of a symmetric function appearing in the Delta conjecture by Haglund-Remmel-Wilson. We provide an explicit and combinatorial description of the irreducible components of the two-row $\Delta$-Springer variety and compare it to the ordinary two-row Springer fiber as well as Kato's exotic Springer fiber corresponding to a one-row bipartition. In addition to that, we extend the action of the symmetric group on the homology of the two-row $\Delta$-Springer variety to an action of a degenerate affine Hecke algebra and relate this action to a $\mathfrak{gl}_{2}$-tensor space., Comment: 32 pages, many figures, comments welcome

Published
2024

20. Nearly-Tight Bounds for Flow Sparsifiers in Quasi-Bipartite Graphs

Author

Das, Syamantak, Kumar, Nikhil, and Vaz, Daniel

Subjects
Computer Science - Data Structures and Algorithms
Abstract

Flow sparsification is a classic graph compression technique which, given a capacitated graph $G$ on $k$ terminals, aims to construct another capacitated graph $H$, called a flow sparsifier, that preserves, either exactly or approximately, every multicommodity flow between terminals (ideally, with size as a small function of $k$). Cut sparsifiers are a restricted variant of flow sparsifiers which are only required to preserve maximum flows between bipartitions of the terminal set. It is known that exact cut sparsifiers require $2^{\Omega(k)}$ many vertices [Krauthgamer and Rika, SODA 2013], with the hard instances being quasi-bipartite graphs, where there are no edges between non-terminals. On the other hand, it has been shown recently that exact (or even $(1+\varepsilon)$-approximate) flow sparsifiers on networks with just 6 terminals require unbounded size [Krauthgamer and Mosenzon, SODA 2023, Chen and Tan, SODA 2024]. In this paper, we construct exact flow sparsifiers of size $3^{k^{3}}$ and exact cut sparsifiers of size $2^{k^2}$ for quasi-bipartite graphs. In particular, the flow sparsifiers are contraction-based, that is, they are obtained from the input graph by (vertex) contraction operations. Our main contribution is a new technique to construct sparsifiers that exploits connections to polyhedral geometry, and that can be generalized to graphs with a small separator that separates the graph into small components. We also give an improved reduction theorem for graphs of bounded treewidth [Andoni et al., SODA 2011], implying a flow sparsifier of size $O(k\cdot w)$ and quality $O\bigl(\frac{\log w}{\log \log w}\bigr)$, where $w$ is the treewidth.

Published
2024
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21. Measurement and analysis of the $^{246}$Cm and $^{248}$Cm neutron capture cross-sections at the EAR2 of the n TOF facility

Author

Alcayne, V., Kimura, A., Mendoza, E., Cano-Ott, D., Aberle, O., Álvarez-Velarde, F., Amaducci, S., Andrzejewski, J., Audouin, L., Bécares, V., Babiano-Suarez, V., Bacak, M., Barbagallo, M., Bečvář, F., Bellia, G., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A., Busso, M., Caamaño, M., Caballero-Ontanaya, L., Calviño, F., Calviani, M., Casanovas, A., Cerutti, F., Chen, Y. H., Chiaveri, E., Colonna, N., Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Cristallo, S., Damone, L. A., Diakaki, M., Dietz, M., Domingo-Pardo, C., Dressler, R., Dupont, E., Durán, I., Eleme, Z., Fernández-Domınguez, B., Ferrari, A., Finocchiaro, P., Furman, V., Göbel, K., Garg, R., Gawlik-Ramiega, A., Gilardoni, S., Glodariu, T., Gonçalves, I. F., González-Romero, E., Guerrero, C., Gunsing, F., Harada, H., Heinitz, S., Heyse, J., Jenkins, D. G., Jericha, E., Käppeler, F., Kadi, Y., Kivel, N., Kokkoris, M., Kopatch, Y., Krtička, M., Kurtulgil, D., Ladarescu, I., Lederer-Woods, C., Leeb, H., Lerendegui-Marco, J., Meo, S. Lo, Lonsdale, S. J., Macina, D., Manna, A., Martınez, T., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Matteucci, F., Maugeri, E. A., Mazzone, A., Mengoni, A., Michalopoulou, V., Milazzo, P. M., Mingrone, F., Musumarra, A., Negret, A., Nolte, R., Ogállar, F., Oprea, A., Patronis, N., Pavlik, A., de Rada, A. Pérez, Perkowski, J., Persanti, L., Porras, I., Praena, J., Quesada, J. M., Radeck, D., Ramos-Doval, D., Rauscher, T., Reifarth, R., Rochman, D., Romanets, Y., Rubbia, C., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schumann, D., Smith, A. G., Sosnin, N. V., Stamatopoulos, A., Tagliente, G., Tain, J. L., Talip, T., Tarifeño-Saldivia, A., Tassan-Got, L., Torres-Sánchez, P., Tsinganis, A., Ulrich, J., Urlass, S., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Woods, P. J., Wright, T., and Žugec, P.

Subjects
Nuclear Experiment
Abstract

The $^{246}$Cm(n,$\gamma$) and $^{248}$Cm(n,$\gamma$) cross-sections have been measured at the Experimental Area 2 (EAR2) of the n_TOF facility at CERN with three C$_6$D$_6$ detectors. This measurement is part of a collective effort to improve the capture cross-section data for Minor Actinides (MAs), which are required to estimate the production and transmutation rates of these isotopes in light water reactors and innovative reactor systems. In particular, the neutron capture in $^{246}$Cm and $^{248}$Cm open the path for the formation of other Cm isotopes and heavier elements such as Bk and Cf and the knowledge of (n,$\gamma$) cross-sections of these Cm isotopes plays an important role in the transport, transmutation and storage of the spent nuclear fuel. The reactions $^{246}$Cm(n,$\gamma$) and $^{248}$Cm(n,$\gamma$) have been the two first capture measurements analyzed at n_TOF EAR2. Until this experiment and two recent measurements performed at J-PARC, there was only one set of data of the capture cross-sections of $^{246}$Cm and $^{248}$Cm, that was obtained in 1969 in an underground nuclear explosion experiment. In the measurement at n_TOF a total of 13 resonances of $^{246}$Cm between 4 and 400 eV and 5 of $^{248}$Cm between 7 and 100 eV have been identified and fitted. The radiative kernels obtained for $^{246}$Cm are compatible with JENDL-5, but some of them are not with JENDL-4, which has been adopted by JEFF-3.3 and ENDF/B-VIII.0. The radiative kernels obtained for the first three $^{248}$Cm resonances are compatible with JENDL-5, however, the other two are not compatible with any other evaluation and are 20% and 60% larger than JENDL-5.

Published
2024

22. xTower: A Multilingual LLM for Explaining and Correcting Translation Errors

Author

Treviso, Marcos, Guerreiro, Nuno M., Agrawal, Sweta, Rei, Ricardo, Pombal, José, Vaz, Tania, Wu, Helena, Silva, Beatriz, van Stigt, Daan, and Martins, André F. T.

Subjects
Computer Science - Computation and Language
Abstract

While machine translation (MT) systems are achieving increasingly strong performance on benchmarks, they often produce translations with errors and anomalies. Understanding these errors can potentially help improve the translation quality and user experience. This paper introduces xTower, an open large language model (LLM) built on top of TowerBase designed to provide free-text explanations for translation errors in order to guide the generation of a corrected translation. The quality of the generated explanations by xTower are assessed via both intrinsic and extrinsic evaluation. We ask expert translators to evaluate the quality of the explanations across two dimensions: relatedness towards the error span being explained and helpfulness in error understanding and improving translation quality. Extrinsically, we test xTower across various experimental setups in generating translation corrections, demonstrating significant improvements in translation quality. Our findings highlight xTower's potential towards not only producing plausible and helpful explanations of automatic translations, but also leveraging them to suggest corrected translations.

Published
2024

23. CLIP-Branches: Interactive Fine-Tuning for Text-Image Retrieval

Author

Lülf, Christian, Martins, Denis Mayr Lima, Salles, Marcos Antonio Vaz, Zhou, Yongluan, and Gieseke, Fabian

Subjects
Computer Science - Information Retrieval
Abstract

The advent of text-image models, most notably CLIP, has significantly transformed the landscape of information retrieval. These models enable the fusion of various modalities, such as text and images. One significant outcome of CLIP is its capability to allow users to search for images using text as a query, as well as vice versa. This is achieved via a joint embedding of images and text data that can, for instance, be used to search for similar items. Despite efficient query processing techniques such as approximate nearest neighbor search, the results may lack precision and completeness. We introduce CLIP-Branches, a novel text-image search engine built upon the CLIP architecture. Our approach enhances traditional text-image search engines by incorporating an interactive fine-tuning phase, which allows the user to further concretize the search query by iteratively defining positive and negative examples. Our framework involves training a classification model given the additional user feedback and essentially outputs all positively classified instances of the entire data catalog. By building upon recent techniques, this inference phase, however, is not implemented by scanning the entire data catalog, but by employing efficient index structures pre-built for the data. Our results show that the fine-tuned results can improve the initial search outputs in terms of relevance and accuracy while maintaining swift response times

Published
2024

24. The PLATO Mission

Author

Rauer, Heike, Aerts, Conny, Cabrera, Juan, Deleuil, Magali, Erikson, Anders, Gizon, Laurent, Goupil, Mariejo, Heras, Ana, Lorenzo-Alvarez, Jose, Marliani, Filippo, Martin-Garcia, César, Mas-Hesse, J. Miguel, O'Rourke, Laurence, Osborn, Hugh, Pagano, Isabella, Piotto, Giampaolo, Pollacco, Don, Ragazzoni, Roberto, Ramsay, Gavin, Udry, Stéphane, Appourchaux, Thierry, Benz, Willy, Brandeker, Alexis, Güdel, Manuel, Janot-Pacheco, Eduardo, Kabath, Petr, Kjeldsen, Hans, Min, Michiel, Santos, Nuno, Smith, Alan, Suarez, Juan-Carlos, Werner, Stephanie C., Aboudan, Alessio, Abreu, Manuel, a, Lorena Acu, Adams, Moritz, Adibekyan, Vardan, Affer, Laura, Agneray, François, Agnor, Craig, Børsen-Koch, Victor Aguirre, Ahmed, Saad, Aigrain, Suzanne, Al-Bahlawan, Ashraf, Gil, M de los Angeles Alcacera, Alei, Eleonora, Alencar, Silvia, Alexander, Richard, Alfonso-Garzón, Julia, Alibert, Yann, Prieto, Carlos Allende, Almeida, Leonardo, Sobrino, Roi Alonso, Altavilla, Giuseppe, Althaus, Christian, Trujillo, Luis Alonso Alvarez, Amarsi, Anish, Eiff, Matthias Ammler-von, Amôres, Eduardo, Andrade, Laerte, Antoniadis-Karnavas, Alexandros, António, Carlos, del Moral, Beatriz Aparicio, Appolloni, Matteo, Arena, Claudio, Armstrong, David, Aliaga, Jose Aroca, Asplund, Martin, Audenaert, Jeroen, Auricchio, Natalia, Avelino, Pedro, Baeke, Ann, Baillié, Kevin, Balado, Ana, Balagueró, Pau Ballber, Balestra, Andrea, Ball, Warrick, Ballans, Herve, Ballot, Jerome, Barban, Caroline, Barbary, Gaële, Barbieri, Mauro, Forteza, Sebasti Barceló, Barker, Adrian, Barklem, Paul, Barnes, Sydney, Navascues, David Barrado, Barragan, Oscar, Baruteau, Clément, Basu, Sarbani, Baudin, Frederic, Baumeister, Philipp, Bayliss, Daniel, Bazot, Michael, Beck, Paul G., Bedding, Tim, Belkacem, Kevin, Bellinger, Earl, Benatti, Serena, Benomar, Othman, Bérard, Diane, Bergemann, Maria, Bergomi, Maria, Bernardo, Pierre, Biazzo, Katia, Bignamini, Andrea, Bigot, Lionel, Billot, Nicolas, Binet, Martin, Biondi, David, Biondi, Federico, Birch, Aaron C., Bitsch, Bertram, Ceballos, Paz Victoria Bluhm, Bódi, Attila, Bognár, Zsófia, Boisse, Isabelle, Bolmont, Emeline, Bonanno, Alfio, Bonavita, Mariangela, Bonfanti, Andrea, Bonfils, Xavier, Bonito, Rosaria, Bonomo, Aldo Stefano, Börner, Anko, Saikia, Sudeshna Boro, Martín, Elisa Borreguero, Borsa, Francesco, Borsato, Luca, Bossini, Diego, Bouchy, Francois, Boué, Gwenaël, Boufleur, Rodrigo, Boumier, Patrick, Bourrier, Vincent, Bowman, Dominic M., Bozzo, Enrico, Bradley, Louisa, Bray, John, Bressan, Alessandro, Breton, Sylvain, Brienza, Daniele, Brito, Ana, Brogi, Matteo, Brown, Beverly, Brown, David J. A., Brun, Allan Sacha, Bruno, Giovanni, Bruns, Michael, Buchhave, Lars A., Bugnet, Lisa, Buldgen, Gaël, Burgess, Patrick, Busatta, Andrea, Busso, Giorgia, Buzasi, Derek, Caballero, José A., Cabral, Alexandre, Gomez, Juan-Francisco Cabrero, Calderone, Flavia, Cameron, Robert, Cameron, Andrew, Campante, Tiago, Gestal, Néstor Campos, Martins, Bruno Leonardo Canto, Cara, Christophe, Carone, Ludmila, Carrasco, Josep Manel, Casagrande, Luca, Casewell, Sarah L., Cassisi, Santi, Castellani, Marco, Castro, Matthieu, Catala, Claude, Fernández, Irene Catalán, Catelan, Márcio, Cegla, Heather, Cerruti, Chiara, Cessa, Virginie, Chadid, Merieme, Chaplin, William, Charpinet, Stephane, Chiappini, Cristina, Chiarucci, Simone, Chiavassa, Andrea, Chinellato, Simonetta, Chirulli, Giovanni, Christensen-Dalsgaard, Jørgen, Church, Ross, Claret, Antonio, Clarke, Cathie, Claudi, Riccardo, Clermont, Lionel, Coelho, Hugo, Coelho, Joao, Cogato, Fabrizio, Colomé, Josep, Condamin, Mathieu, García, Fernando Conde, Conseil, Simon, Corbard, Thierry, Correia, Alexandre C. M., Corsaro, Enrico, Cosentino, Rosario, Costes, Jean, Cottinelli, Andrea, Covone, Giovanni, Creevey, Orlagh L., Crida, Aurelien, Csizmadia, Szilard, Cunha, Margarida, Curry, Patrick, da Costa, Jefferson, da Silva, Francys, Dalal, Shweta, Damasso, Mario, Damiani, Cilia, Damiani, Francesco, Chagas, Maria Liduina das, Davies, Melvyn, Davies, Guy, Davies, Ben, Davison, Gary, de Almeida, Leandro, de Angeli, Francesca, de Barros, Susana Cristina Cabral, Leão, Izan de Castro, de Freitas, Daniel Brito, de Freitas, Marcia Cristina, De Martino, Domitilla, de Medeiros, José Renan, de Paula, Luiz Alberto, Gómez, Álvaro de Pedraza, de Plaa, Jelle, De Ridder, Joris, Deal, Morgan, Decin, Leen, Deeg, Hans, Innocenti, Scilla Degl, Deheuvels, Sebastien, del Burgo, Carlos, Del Sordo, Fabio, Delgado-Mena, Elisa, Demangeon, Olivier, Denk, Tilmann, Derekas, Aliz, Desert, Jean-Michel, Desidera, Silvano, Dexet, Marc, Di Criscienzo, Marcella, Di Giorgio, Anna Maria, Di Mauro, Maria Pia, Rial, Federico Jose Diaz, Díaz-García, José-Javier, Dima, Marco, Dinuzzi, Giacomo, Dionatos, Odysseas, Distefano, Elisa, Nascimento Jr., Jose-Dias do, Domingo, Albert, D'Orazi, Valentina, Dorn, Caroline, Doyle, Lauren, Duarte, Elena, Ducellier, Florent, Dumaye, Luc, Dumusque, Xavier, Dupret, Marc-Antoine, Eggenberger, Patrick, Ehrenreich, David, Eigmüller, Philipp, Eising, Johannes, Emilio, Marcelo, Eriksson, Kjell, Ermocida, Marco, Giribaldi, Riano Isidoro Escate, Eschen, Yoshi, ez, Lucía Espinosa Yá, Estrela, In s, Evans, Dafydd Wyn, Fabbian, Damian, Fabrizio, Michele, Faria, João Pedro, Farina, Maria, Farinato, Jacopo, Feliz, Dax, Feltzing, Sofia, Fenouillet, Thomas, Fernández, Miguel, Ferrari, Lorenza, Ferraz-Mello, Sylvio, Fialho, Fabio, Fienga, Agnes, Figueira, Pedro, Fiori, Laura, Flaccomio, Ettore, Focardi, Mauro, Foley, Steve, Fontignie, Jean, Ford, Dominic, Fornazier, Karin, Forveille, Thierry, Fossati, Luca, Franca, Rodrigo de Marca, da Silva, Lucas Franco, Frasca, Antonio, Fridlund, Malcolm, Furlan, Marco, Gabler, Sarah-Maria, Gaido, Marco, Gallagher, Andrew, Sempere, Paloma I. Gallego, Galli, Emanuele, García, Rafael A., Hernández, Antonio García, Munoz, Antonio Garcia, García-Vázquez, Hugo, Haba, Rafael Garrido, Gaulme, Patrick, Gauthier, Nicolas, Gehan, Charlotte, Gent, Matthew, Georgieva, Iskra, Ghigo, Mauro, Giana, Edoardo, Gill, Samuel, Girardi, Leo, Winter, Silvia Giuliatti, Giusi, Giovanni, da Silva, João Gomes, Zazo, Luis Jorge Gómez, Gomez-Lopez, Juan Manuel, Hernández, Jonay Isai González, Murillo, Kevin Gonzalez, Melchor, Alejandro Gonzalo, Gorius, Nicolas, Gouel, Pierre-Vincent, Goulty, Duncan, Granata, Valentina, Grenfell, John Lee, bach, Denis Grie, Grolleau, Emmanuel, Grouffal, Salomé, Grziwa, Sascha, Guarcello, Mario Giuseppe, Gueguen, Lo c, Guenther, Eike Wolf, Guilhem, Terrasa, Guillerot, Lucas, Guillot, Tristan, Guiot, Pierre, Guterman, Pascal, Gutiérrez, Antonio, Gutiérrez-Canales, Fernando, Hagelberg, Janis, Haldemann, Jonas, Hall, Cassandra, Handberg, Rasmus, Harrison, Ian, Harrison, Diana L., Hasiba, Johann, Haswell, Carole A., Hatalova, Petra, Hatzes, Artie, Haywood, Raphaelle, Hébrard, Guillaume, Heckes, Frank, Heiter, Ulrike, Hekker, Saskia, Heller, René, Helling, Christiane, Helminiak, Krzysztof, Hemsley, Simon, Heng, Kevin, Herbst, Konstantin, Hermans, Aline, Hermes, JJ, Torres, Nadia Hidalgo, Hinkel, Natalie, Hobbs, David, Hodgkin, Simon, Hofmann, Karl, Hojjatpanah, Saeed, Houdek, Günter, Huber, Daniel, Huesler, Joseph, Hui-Bon-Hoa, Alain, Huygen, Rik, Huynh, Duc-Dat, Iro, Nicolas, Irwin, Jonathan, Irwin, Mike, Izidoro, André, Jacquinod, Sophie, Jannsen, Nicholas Emborg, Janson, Markus, Jeszenszky, Harald, Jiang, Chen, Mancebo, Antonio José Jimenez, Jofre, Paula, Johansen, Anders, Johnston, Cole, Jones, Geraint, Kallinger, Thomas, Kálmán, Szilárd, Kanitz, Thomas, Karjalainen, Marie, Karjalainen, Raine, Karoff, Christoffer, Kawaler, Steven, Kawata, Daisuke, Keereman, Arnoud, Keiderling, David, Kennedy, Tom, Kenworthy, Matthew, Kerschbaum, Franz, Kidger, Mark, Kiefer, Flavien, Kintziger, Christian, Kislyakova, Kristina, Kiss, László, Klagyivik, Peter, Klahr, Hubert, Klevas, Jonas, Kochukhov, Oleg, Köhler, Ulrich, Kolb, Ulrich, Koncz, Alexander, Korth, Judith, Kostogryz, Nadiia, Kovács, Gábor, Kovács, József, Kozhura, Oleg, Krivova, Natalie, Kucinskas, Arunas, Kuhlemann, Ilyas, Kupka, Friedrich, Laauwen, Wouter, Labiano, Alvaro, Lagarde, Nadege, Laget, Philippe, Laky, Gunter, Lam, Kristine Wai Fun, Lambrechts, Michiel, Lammer, Helmut, Lanza, Antonino Francesco, Lanzafame, Alessandro, Martiz, Mariel Lares, Laskar, Jacques, Latter, Henrik, Lavanant, Tony, Lawrenson, Alastair, Lazzoni, Cecilia, Lebre, Agnes, Lebreton, Yveline, Etangs, Alain Lecavelier des, Lee, Katherine, Leinhardt, Zoe, Leleu, Adrien, Lendl, Monika, Leto, Giuseppe, Levillain, Yves, Libert, Anne-Sophie, Lichtenberg, Tim, Ligi, Roxanne, Lignieres, Francois, Lillo-Box, Jorge, Linsky, Jeffrey, Liu, John Scige, Loidolt, Dominik, Longval, Yuying, Lopes, Ilídio, Lorenzani, Andrea, Ludwig, Hans-Guenter, Lund, Mikkel, Lundkvist, Mia Sloth, Luri, Xavier, Maceroni, Carla, Madden, Sean, Madhusudhan, Nikku, Maggio, Antonio, Magliano, Christian, Magrin, Demetrio, Mahy, Laurent, Maibaum, Olaf, Malac-Allain, LeeRoy, Malapert, Jean-Christophe, Malavolta, Luca, Maldonado, Jesus, Mamonova, Elena, Manchon, Louis, Manjón, Andres, Mann, Andrew, Mantovan, Giacomo, Marafatto, Luca, Marconi, Marcella, Mardling, Rosemary, Marigo, Paola, Marinoni, Silvia, Marques, rico, Marques, Joao Pedro, Marrese, Paola Maria, Marshall, Douglas, Perales, Silvia Martínez, Mary, David, Marzari, Francesco, Masana, Eduard, Mascher, Andrina, Mathis, Stéphane, Mathur, Savita, Vodopivec, Iris Martín, Figueiredo, Ana Carolina Mattiuci, Maxted, Pierre F. L., Mazeh, Tsevi, Mazevet, Stephane, Mazzei, Francesco, McCormac, James, McMillan, Paul, Menou, Lucas, Merle, Thibault, Meru, Farzana, Mesa, Dino, Messina, Sergio, Mészáros, Szabolcs, Meunier, Nadége, Meunier, Jean-Charles, Micela, Giuseppina, Michaelis, Harald, Michel, Eric, Michielsen, Mathias, Michtchenko, Tatiana, Miglio, Andrea, Miguel, Yamila, Milligan, David, Mirouh, Giovanni, Mitchell, Morgan, Moedas, Nuno, Molendini, Francesca, Molnár, László, Mombarg, Joey, Montalban, Josefina, Montalto, Marco, Monteiro, Mário J. P. F. G., Sánchez, Francisco Montoro, Morales, Juan Carlos, Morales-Calderon, Maria, Morbidelli, Alessandro, Mordasini, Christoph, Moreau, Chrystel, Morel, Thierry, Morello, Guiseppe, Morin, Julien, Mortier, Annelies, Mosser, Beno t, Mourard, Denis, Mousis, Olivier, Moutou, Claire, Mowlavi, Nami, Moya, Andrés, Muehlmann, Prisca, Muirhead, Philip, Munari, Matteo, Musella, Ilaria, Mustill, Alexander James, Nardetto, Nicolas, Nardiello, Domenico, Narita, Norio, Nascimbeni, Valerio, Nash, Anna, Neiner, Coralie, Nelson, Richard P., Nettelmann, Nadine, Nicolini, Gianalfredo, Nielsen, Martin, Niemi, Sami-Matias, Noack, Lena, Noels-Grotsch, Arlette, Noll, Anthony, Norazman, Azib, Norton, Andrew J., Nsamba, Benard, Ofir, Aviv, Ogilvie, Gordon, Olander, Terese, Olivetto, Christian, Olofsson, Göran, Ong, Joel, Ortolani, Sergio, Oshagh, Mahmoudreza, Ottacher, Harald, Ottensamer, Roland, Ouazzani, Rhita-Maria, Paardekooper, Sijme-Jan, Pace, Emanuele, Pajas, Miriam, Palacios, Ana, Palandri, Gaelle, Palle, Enric, Paproth, Carsten, Parro, Vanderlei, Parviainen, Hannu, Granado, Javier Pascual, Passegger, Vera Maria, Pastor-Morales, Carmen, Pätzold, Martin, Pedersen, May Gade, Hidalgo, David Pena, Pepe, Francesco, Pereira, Filipe, Persson, Carina M., Pertenais, Martin, Peter, Gisbert, Petit, Antoine C., Petit, Pascal, Pezzuto, Stefania, Pichierri, Gabriele, Pietrinferni, Adriano, Pinheiro, Fernando, Pinsonneault, Marc, Plachy, Emese, Plasson, Philippe, Plez, Bertrand, Poppenhaeger, Katja, Poretti, Ennio, Portaluri, Elisa, Portell, Jordi, de Mello, Gustavo Frederico Porto, Poyatos, Julien, Pozuelos, Francisco J., Moroni, Pier Giorgio Prada, Pricopi, Dumitru, Prisinzano, Loredana, Quade, Matthias, Quirrenbach, Andreas, Reina, Julio Arturo Rabanal, Soares, Maria Cristina Rabello, Raimondo, Gabriella, Rainer, Monica, Rodón, Jose Ramón, Ramón-Ballesta, Alejandro, Zapata, Gonzalo Ramos, Rätz, Stefanie, Rauterberg, Christoph, Redman, Bob, Redmer, Ronald, Reese, Daniel, Regibo, Sara, Reiners, Ansgar, Reinhold, Timo, Renie, Christian, Ribas, Ignasi, Ribeiro, Sergio, Ricciardi, Thiago Pereira, Rice, Ken, Richard, Olivier, Riello, Marco, Rieutord, Michel, Ripepi, Vincenzo, Rixon, Guy, Rockstein, Steve, Ortiz, José Ramón Rodón, Rodríguez, María Teresa Rodrigo, Amor, Alberto Rodríguez, Díaz, Luisa Fernanda Rodríguez, Garcia, Juan Pablo Rodriguez, Rodriguez-Gomez, Julio, Roehlly, Yannick, Roig, Fernando, Rojas-Ayala, Bárbara, Rolf, Tobias, Rørsted, Jakob Lysgaard, Rosado, Hugo, Rosotti, Giovanni, Roth, Olivier, Roth, Markus, Rousseau, Alex, Roxburgh, Ian, Roy, Fabrice, Royer, Pierre, Ruane, Kirk, Mastropasqua, Sergio Rufini, de Galarreta, Claudia Ruiz, Russi, Andrea, Saar, Steven, Saillenfest, Melaine, Salaris, Maurizio, Salmon, Sebastien, Saltas, Ippocratis, Samadi, Réza, Samadi, Aunia, Samra, Dominic, da Silva, Tiago Sanches, Carrasco, Miguel Andrés Sánchez, Santerne, Alexandre, Pé, Amaia Santiago, Santoli, Francesco, Santos, ngela R. G., Mesa, Rosario Sanz, Sarro, Luis Manuel, Scandariato, Gaetano, Schäfer, Martin, Schlafly, Edward, Schmider, François-Xavier, Schneider, Jean, Schou, Jesper, Schunker, Hannah, Schwarzkopf, Gabriel Jörg, Serenelli, Aldo, Seynaeve, Dries, Shan, Yutong, Shapiro, Alexander, Shipman, Russel, Sicilia, Daniela, sanmartin, Maria Angeles Sierra, Sigot, Axelle, Silliman, Kyle, Silvotti, Roberto, Simon, Attila E., Napoli, Ricardo Simoyama, Skarka, Marek, Smalley, Barry, Smiljanic, Rodolfo, Smit, Samuel, Smith, Alexis, Smith, Leigh, Snellen, Ignas, Sódor, Ádám, Sohl, Frank, Solanki, Sami K., Sortino, Francesca, Sousa, Sérgio, Southworth, John, Souto, Diogo, Sozzetti, Alessandro, Stamatellos, Dimitris, Stassun, Keivan, Steller, Manfred, Stello, Dennis, Stelzer, Beate, Stiebeler, Ulrike, Stokholm, Amalie, Storelvmo, Trude, Strassmeier, Klaus, Strøm, Paul Anthony, Strugarek, Antoine, Sulis, Sophia, vanda, Michal, Szabados, László, Szabó, Róbert, Szabó, Gyula M., Szuszkiewicz, Ewa, Talens, Geert Jan, Teti, Daniele, Theisen, Tom, Thévenin, Frédéric, Thoul, Anne, Tiphene, Didier, Titz-Weider, Ruth, Tkachenko, Andrew, Tomecki, Daniel, Tonfat, Jorge, Tosi, Nicola, Trampedach, Regner, Traven, Gregor, Triaud, Amaury, Trønnes, Reidar, Tsantaki, Maria, Tschentscher, Matthias, Turin, Arnaud, Tvaruzka, Adam, Ulmer, Bernd, Ulmer-Moll, Solène, Ulusoy, Ceren, Umbriaco, Gabriele, Valencia, Diana, Valentini, Marica, Valio, Adriana, Guijarro, Ángel Luis Valverde, Van Eylen, Vincent, Van Grootel, Valerie, van Kempen, Tim A., Van Reeth, Timothy, Van Zelst, Iris, Vandenbussche, Bart, Vasiliou, Konstantinos, Vasilyev, Valeriy, de Mascarenhas, David Vaz, Vazan, Allona, Nunez, Marina Vela, Velloso, Eduardo Nunes, Ventura, Rita, Ventura, Paolo, Venturini, Julia, Trallero, Isabel Vera, Veras, Dimitri, Verdugo, Eva, Verma, Kuldeep, Vibert, Didier, Martinez, Tobias Vicanek, Vida, Krisztián, Vigan, Arthur, Villacorta, Antonio, Villaver, Eva, Aparicio, Marcos Villaverde, Viotto, Valentina, Vorobyov, Eduard, Vorontsov, Sergey, Wagner, Frank W., Walloschek, Thomas, Walton, Nicholas, Walton, Dave, Wang, Haiyang, Waters, Rens, Watson, Christopher, Wedemeyer, Sven, Weeks, Angharad, Weingrill, Jörg, Weiss, Annita, Wendler, Belinda, West, Richard, Westerdorff, Karsten, Westphal, Pierre-Amaury, Wheatley, Peter, White, Tim, Whittaker, Amadou, Wickhusen, Kai, Wilson, Thomas, Windsor, James, Winter, Othon, Winther, Mark Lykke, Winton, Alistair, Witteck, Ulrike, Witzke, Veronika, Woitke, Peter, Wolter, David, Wuchterl, Günther, Wyatt, Mark, Yang, Dan, Yu, Jie, Sanchez, Ricardo Zanmar, Osorio, María Rosa Zapatero, Zechmeister, Mathias, Zhou, Yixiao, Ziemke, Claas, and Zwintz, Konstanze

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract

PLATO (PLAnetary Transits and Oscillations of stars) is ESA's M3 mission designed to detect and characterise extrasolar planets and perform asteroseismic monitoring of a large number of stars. PLATO will detect small planets (down to <2 R_(Earth)) around bright stars (<11 mag), including terrestrial planets in the habitable zone of solar-like stars. With the complement of radial velocity observations from the ground, planets will be characterised for their radius, mass, and age with high accuracy (5 %, 10 %, 10 % for an Earth-Sun combination respectively). PLATO will provide us with a large-scale catalogue of well-characterised small planets up to intermediate orbital periods, relevant for a meaningful comparison to planet formation theories and to better understand planet evolution. It will make possible comparative exoplanetology to place our Solar System planets in a broader context. In parallel, PLATO will study (host) stars using asteroseismology, allowing us to determine the stellar properties with high accuracy, substantially enhancing our knowledge of stellar structure and evolution. The payload instrument consists of 26 cameras with 12cm aperture each. For at least four years, the mission will perform high-precision photometric measurements. Here we review the science objectives, present PLATO's target samples and fields, provide an overview of expected core science performance as well as a description of the instrument and the mission profile at the beginning of the serial production of the flight cameras. PLATO is scheduled for a launch date end 2026. This overview therefore provides a summary of the mission to the community in preparation of the upcoming operational phases.

Published
2024

25. How disinformation and fake news impact public policies?: A review of international literature

Author

Silva, Ergon Cugler de Moraes and Vaz, Jose Carlos

Subjects
Computer Science - Computers and Society, Computer Science - Information Theory
Abstract

This study investigates the impact of disinformation on public policies. Using 28 sets of keywords in eight databases, a systematic review was carried out following the Prisma 2020 model (Page et al., 2021). After applying filters and inclusion and exclusion criteria to 4,128 articles and materials found, 46 publications were analyzed, resulting in 23 disinformation impact categories. These categories were organized into two main axes: State and Society and Actors and Dynamics, covering impacts on State actors, society actors, State dynamics and society dynamics. The results indicate that disinformation affects public decisions, adherence to policies, prestige of institutions, perception of reality, consumption, public health and other aspects. Furthermore, this study suggests that disinformation should be treated as a public problem and incorporated into the public policy research agenda, contributing to the development of strategies to mitigate its effects on government actions.

Published
2024

26. Detector Development for a Double-Differential Cross Section Experiment with the Emission of Light Charged Particles from High Energy Neutrons

Author

Dietz M., Beyer R., Junghans A., Nolte R., Pirovano E., Romanets Y., and Vaz P.

Subjects
n_tof, double-differential cross section, carbon, time-of-flight, high neutron energy, particle detector telescope, neutron dosimetry, Physics, QC1-999
Abstract

Double-differential cross section (DDX) data on the neutron-induced emission of light charged particles are required for assessing the risk of secondary tumors in particle radiation therapy. There are only very few DDX data available for discrete neutron energies close to and above 100 MeV for carbon. A measurement of DDX on carbon is planned at continuous neutron energies from 20 MeV to 200 MeV with particle detector telescopes at n_TOF (CERN). Several detector development criteria and challenges are reported such as coincidence timing and electromagnetic oscillations for high neutron energy events with particle separation.

Published
2023
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27. A mobile radiation detection system for security inspection and monitoring

Author

Marques Luís, Coito Rui, Fernandes Sofia, Costa Tiago, Vale Alberto, and Vaz Pedro

Subjects
plastic scintillators, silicon photomultiplier, neutron and gamma-ray detection, source localization, mobile radiation detection system, security scenarios, Physics, QC1-999
Abstract

In Nuclear Security scenarios, traditional radiation portal monitors are normally fixed, large, and expensive equipment. This study introduces an innovative, cost-effective solution: a lightweight, compact, mobile gamma-ray/beta and neutron detection system, comprising two plastic scintillators with silicon photomultipliers. Designed for inspecting maritime containers, a real-time gamma-ray source search algorithm operates during perimeter scans. Using maximum likelihood estimation, the algorithm computes radiation source coordinates. To optimize the detection system’s path and enhance survey quality (informed path), a profit function is employed. This function is grounded in either gamma-ray count analysis or source position estimations, providing dual approaches to improve source position accuracy. Evaluating this approach, simulations used a 137Cs source inside a container, with gamma-ray counts adjusted for geometric detection efficiency and material attenuation. The informed path generated by the source search algorithm is compared to predefined paths, revealing substantial improvements in source height estimation accuracy and reduced confidence intervals. The use of profit functions to refine the initial path enhances system reliability and streamlines inspection time.

Published
2023
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28. Measurement of the 241Am(n,γ) cross section at the n_TOF facility at CERN

Author

Oprea A., Gunsing F., Schillebeeckx P., Aberle O., Bacak M., Berthoumieux E., Cano-Ott D., Diakaki M., Dupont E., Geslot B., Glodariu† T., Heyse J., Mendoza E., Negret A., Alcayne V., Amaducci S., Andrzejewski J., Audouin L., Bécares V., Babiano-Suarez V., Barbagallo M., Bečvář F., Bellia G., Billowes J., Bosnar D., Brown A., Busso M., Caamaño M., Caballero-Ontanaya L., Calviño F., Calviani M., Casanovas A., Cerutti F., Chen Y. H., Chiaveri E., Colonna N., Cortés G., Cortés-Giraldo M. A., Cosentino L., Cristallo S., Damone L. A., Dietz M., Domingo-Pardo C., Dressler R., Durán I., Eleme Z., Fernández-Domínguez B., Ferrari A., Finocchiaro P., Furman V., Göbel K., Garg R., Gawlik-Ramięga A., Gilardoni S., Gonçalves I. F., González-Romero E., Guerrero C., Harada H., Heinitz S., Jenkins D. G., Jericha E., Käppeler† F., Kaur G., Kadi Y., Kimura A., Kivel N., Kokkoris M., Kopatch Y., Krtička M., Kurtulgil D., Ladarescu I., Lederer-Woods C., Leeb H., Lerendegui-Marco J., Lo Meo S., Lonsdale S. J., Macina D., Manna A., Martínez T., Masi A., Massimi C., Mastinu P., Mastromarco M., Matteucci F., Maugeri E. A., Mazzone A., Mengoni A., Michalopoulou V., Milazzo P. M., Mingrone F., Musumarra A., Nolte R., Ogállar F., Patronis N., Pavlik A., Perkowski J., Piersanti L., Porras I., Praena J., Quesada J. M., Radeck D., Ramos-Doval D., Rauscher T., Reifarth R., Rochman D., Rubbia C., Sabaté-Gilarte M., Saxena A., Schumann D., Smith A. G., Sosnin N. V., Stamatopoulos A., Tagliente G., Tain J. L., Talip T., Tarifeño-Saldivia A., Tassan-Got L., Torres-Sánchez P., Tsinganis A., Ulrich J., Urlass S., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Vlachoudis V., Vlastou R., Wallner A., Woods P. J., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The neutron capture cross section of 241Am is an important quantity for nuclear energy production and fuel cycle scenarios. Several measurements have been performed in recent years with the aim to reduce existing uncertainties in evaluated data. Two previous measurements, performed at the 185 m flight-path station EAR1 of the neutron time-of-flight facility n_TOF at CERN, have permitted to substantially extend the resolved resonance region, but suffered in the near-thermal energy range from the unfavorable signal-to-background ratio resulting from the combination of the high radioactivity of 241Am and the rather low thermal neutron flux. The here presented 241Am(n,γ) measurement, performed with C6D6 liquid scintillator gamma detectors at the 20 m flight-path station EAR2 of the n_TOF facility, took advantage of the much higher neutron flux. The current status of the analysis of the data, focussed on the low-energy region, will be described here.

Published
2023
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29. Results of the 244Cm, 246Cm and 248Cm neutron-induced capture cross sections measurements at EAR1 and EAR2 of the n_TOF facility

Author

Alcayne V., Mendoza E., Cano-Ott D., Kimura A., Aberle O., Amaducci S., Andrzejewski J., Audouin L., Babiano-Suarez V., Bacak M., Barbagallo M., Bécares V., Bečvář F., Bellia G., Berthoumieux E., Billowes J., Bosnar D., Brown A. S., Busso M., Caamaño M., Caballero L., Calviani M., Calviño F., Casanovas A., Cerutti F., Chen Y. H., Chiaveri E., Colonna N., Cortés G. P., Cortés-Giraldo M. A., Cosentino L., Cristallo S., Damone L. A., Diakaki M., Dietz M., Domingo-Pardo C., Dressler R., Dupont E., Durán I., Eleme Z., Fernández-Domíngez B., Ferrari A., Ferro-Gonçalves I., Finocchiaro P., Furman V., Garg R., Gawlik A., Gilardoni S., Glodariu T., Göbel K., González-Romero E., Guerrero C., Gunsing F., Heinitz S., Heyse J., Jenkins D. G., Jericha E., Kadi Y., Käppeler F., Kivel N., Kokkoris M., Kopatch Y., Krtička M., Kurtulgil D., Ladarescu I., Lederer-Woods C., Lerendegui-Marco J., Lo Meo S., Lonsdale S.-J., Macina D., Manna A., Martínez T., Masi A., Massimi C., Mastinu P. F., Mastromarco M., Matteucci F., Maugeri E., Mazzone A., Mengoni A., Michalopoulou V., Milazzo P. M., Mingrone F., Musumarra A., Negret A., Nolte R., Ogállar F., Oprea A., Patronis N., Pavlik A., Perkowski J., Piersanti L., Porras I., Praena J., Quesada J. M., Radeck D., Ramos Doval D., Reifarth R., Rochman D., Rubbia C., Sabaté-Gilarte M., Saxena A., Schillebeeckx P., Schumann D., Smith A. G., Sosnin N., Stamatopoulos A., Tagliente G., Tain J. L., Talip Z., Tarifeño-Saldivia A. E., Tassan-Got L., Torres-Sánchez P., Tsinganis A., Ulrich J., Urlass S., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Vlachoudis V., Vlastou R., Wallner A., Woods P. J., Wright T. J., and Žugec P.

Subjects
Physics, QC1-999
Abstract

Accurate neutron capture cross section data for minor actinides (MAs) are required to estimate the production and transmutation rates of MAs in light water reactors, critical fast reactors like Gen-IV systems, and other innovative reactor systems such as accelerator driven systems (ADS). In particular, 244Cm, 246Cm and 248Cm play a role in the transport, storage and transmutation of the nuclear waste of the current nuclear reactors, due to the contribution of these isotopes to the radiotoxicity, neutron emission, and decay heat in the spent nuclear fuel. Also, capture reactions in these Cm isotopes open the path for the formation of heavier elements. In this work, the results of the capture cross section measurement on 244Cm, 246Cm and 248Cm performed at the CERN n_TOF facility are presented. It is important to notice that the Cm samples used in the experiment at n_TOF have been used previously in an experiment at J-PARC, this experiment and the previous one done in the 70s with a nuclear explosion were the only previous capture experiments for these isotopes. At n_TOF, the capture cross section measurements of 244Cm, 246Cm and 248Cm were performed at the 20 m vertical flight path (EAR2) with three C6D6 total energy detectors. In addition, the cross section of 244Cm was measured at the 185 m flight path (EAR1) with a Total Absorption Calorimeter (TAC). The combination of measurements in EAR1 and EAR2 has contributed to controlling and reducing the systematic uncertainties in the results. The compatibility of the different measurements performed and the techniques to obtain the results are presented in this paper as well as the procedure to obtain the resonance parameters.

Published
2023
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30. The Stellar 72Ge(n, γ) Cross Section for weak s-process: A First Measurement at n_TOF

Author

Dietz M., Lederer-Woods C., Tattersall A., Battino U., Gunsing F., Heinitz S., Lerendegui-Marco J., Krtička M., Reifarth R., Valenta S., Aberle O., Amaducci S., Andrzejewski J., Audouin L., Bacak M., Balibrea J., Barbagallo M., Bečvář F., Berthoumieux E., Billowes J., Bosnar D., Brown A., Caamaño M., Calviño F., Calviani M., Cano-Ott D., Cardella R., Casanovas A., Cerutti F., Chen Y. H., Chiaveri E., Colonna N., Cortés G., Cortés-Giraldo M. A., Cosentino L., Damone L. A., Diakaki M., Domingo-Pardo C., Dressler R., Dupont E., Durán I., Fernández-Domínguez B., Ferrari A., Ferreira P., Finocchiaro P., Göbel K., García A. R., Gawlik-Ramie˛ga A., Gilardoni S., Glodariu† T., Gonçalves I. F., González-Romero E., Griesmayer E., Guerrero C., Harada H., Heyse J., Jenkins D. G., Jericha E., Käppeler† F., Kadi Y., Kahl D., Kalamara A., Kavrigin P., Kimura A., Kivel N., Kokkoris M., Kurtulgil D., Leal-Cidoncha E., Leeb H., Lo Meo S., Lonsdale S. J., Macina D., Manna A., Marganiec J., Martínez T., Masi A., Massimi C., Mastinu P., Mastromarco M., Maugeri E. A., Mazzone A., Mendoza E., Mengoni A., Milazzo P. M., Mingrone F., Musumarra A., Negret A., Nolte R., Oprea A., Patronis N., Pavlik A., Perkowski J., Porras I., Praena J., Quesada J. M., Radeck D., Rauscher T., Rubbia C., Ryan J. A., Sabaté-Gilarte M., Saxena A., Schillebeeckx P., Schumann D., Smith A. G., Sosnin N. V., Stamatopoulos A., Tagliente G., Tain J. L., Tarifeño-Saldivia A., Tassan-Got L., Vannini G., Variale V., Vaz P., Ventura A., Vlachoudis V., Vlastou R., Wallner A., Warren S., Weiss C., Woods P. J., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The slow neutron capture process (s-process) is responsible for producing about half of the elemental abundances heavier than iron in the universe. Neutron capture cross sections on stable isotopes are a key nuclear physics input for s-process studies. The 72Ge(n, γ) Maxwellian-Averaged Cross Section (MACS) has an important influence on the production of isotopes between Ge and Zr in the weak s-process in massive stars and so far only theoretical estimations are available. An experiment was carried out at the neutron time-of-flight facility n_TOF at CERN to measure the 72Ge(n, γ) reaction for the first time at stellar neutron energies. The capture measurement was performed using an enriched 72GeO2 sample at a flight path length of 184 m, which provided high neutron energy resolution. The prompt gamma rays produced after neutron capture were detected with a set of liquid scintillation detectors (C6D6). The neutron capture yield is derived from the counting spectra taking into account the neutron flux and the gamma-ray detection efficiency using the Pulse Height Weighting Technique. Over 70 new neutron resonances were identified, providing an improved resolved reaction cross section to calculate experimental MACS values for the first time. The experiment, data analysis and the new MACS results will be presented including their impact on stellar nucleosynthesis, which was investigated using the post-processing nucleosynthesis code mppnp for a 25 solar mass model.

Published
2023
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31. New perspectives for neutron capture measurements in the upgraded CERN-n_TOF Facility

Author

Lerendegui-Marco J., Casanovas A., Alcayne V., Aberle O., Altieri S., Amaducci S., Andrzejewski J., Babiano-Suarez V., Bacak M., Balibrea J., Beltrami C., Bennett S., Bernardes A. P., Berthoumieux E., Boromiza M., Bosnar D., Caamaño M., Calviño F., Calviani M., Cano-Ott D., Cerutti F., Cescutti G., Chasapoglou S., Chiaveri E., Colombetti P., Colonna N., Console Camprini P., Cortés G., Cortés-Giraldo M. A., Cosentino L., Cristallo S., Dellmann S., Di Castro M., Di Maria S., Diakaki M., Dietz M., Domingo-Pardo C., Dressler R., Dupont E., Durán I., Eleme Z., Fargier S., Fernández B., Fernández-Domínguez B., Finocchiaro P., Fiore S., Furman V., García-Infantes F., Gawlik-Ramiega A., Gervino G., Gilardoni S., González-Romero E., Guerrero C., Gunsing F., Gustavino C., Heyse J., Hillman W., Jenkins D. G., Jericha E., Junghans A., Kadi Y., Kaperoni K., Kaur G., Kimura A., Knapová I., Kokkoris M., Kopatch Y., Krtička M., Kyritsis N., Ladarescu I., Lederer-Woods C., Lerner G., Manna A., Martínez T., Masi A., Massimi C., Mastinu P., Mastromarco M., Maugeri E. A., Mazzone A., Mendoza E., Mengoni A., Michalopoulou V., Milazzo P. M., Mucciola R., Murtas† F., Musacchio-Gonzalez E., Musumarra A., Negret A., Pérez de Rada A., Pérez-Maroto P., Patronis N., Pavón-Rodríguez J. A., Pellegriti M. G., Perkowski J., Petrone C., Pirovano E., Plaza J., Pomp S., Porras I., Praena J., Quesada J. M., Reifarth R., Rochman D., Romanets Y., Rubbia C., Sánchez A., Sabaté-Gilarte M., Schillebeeckx P., Schumann D., Sekhar A., Smith A. G., Sosnin N. V., Stamati M. E., Sturniolo A., Tagliente G., Tarrío D., Torres-Sánchez P., Urlass S., Vagena E., Valenta S., Variale V., Vaz P., Vecchio G., Vescovi D., Vlachoudis V., Vlastou R., Wallner T., Woods P. J., Wright T., Zarrella R., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The n_TOF facility has just undergone in 2021 a major upgrade with the installation of its third generation spallation target that has been designed to optimize the performance of the two n_TOF time-of-flight lines. This contribution describes the key features and limitations for capture measurements in the two beam lines prior to the target upgrade and presents first results of (n,γ) measurements carried out as part of the commissioning of the upgraded facility. In particular, the energy resolution, a key factor for both increasing the signal-to-background ratio and obtaining accurate resonance parameters, has been clearly improved for the 20 m long vertical beam-line with the new target design while keeping the remarkably high resolution of the long beamline n_TOF-EAR1. The improvements in the n_TOF neutron beam-lines need to be accompanied by improvements in the instrumentation. A review is given on recent detector R&D projects aimed at tackling the existing challenges and further improving the capabilities of this facility.

Published
2023
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32. Compton imaging for enhanced sensitivity (n,γ) cross section TOF experiments: Status and prospects

Author

Domingo-Pardo C., Babiano-Suarez V., Balibrea-Correa J., Caballero L., Ladarescu I., Lerendegui-Marco J., Tarifeño-Saldivia A., Aberle O., Alcayne V., Altieri S., Amaducci S., Andrzejewski J., Bacak M., Beltrami C., Bennett S., Bernardes A. P., Berthoumieux E., Beyer R., Boromiza M., Bosnar D., Caamaño M., Calviño F., Calviani M., Cano-Ott D., Casanovas A., Cerutti F., Cescutti G., Chiaveri E., Colombetti P., Colonna N., Console Camprini P., Cortés G., Cortés-Giraldo M. A., Cosentino L., Cristallo S., Dellmann S., Di Castro M., Di Maria S., Diakaki M., Dietz M., Dressler R., Dupont E., Durán I., Eleme Z., Fargier S., Fernández B., Fernández-Domínguez B., Finocchiaro P., Fiore S., García-Infantes F., Gawlik-Ramie˛ga A., Gervino G., Gilardoni S., González-Romero E., Guerrero C., Gunsing F., Gustavino C., Heyse J., Hillman W., Jenkins D. G., Jericha E., Junghans A., Kadi Y., Kaperoni K., Kaur G., Kimura A., Knapová I., Kokkoris M., Köster U., Krtička M., Kyritsis N., Lederer-Woods C., Lerner G., Manna A., Martínez T., Masi A., Massimi C., Mastinu P., Mastromarco M., Maugeri E. A., Mazzone A., Mendoza E., Mengoni A., Michalopoulou V., Milazzo P. M., Mucciola R., Murtas† F., Musacchio-Gonzalez E., Musumarra A., Negret A., Pérez de Rada A., Pérez-Maroto P., Patronis N., Pavón-Rodríguez J. A., Pellegriti M. G., Perkowski J., Petrone C., Pirovano E., Plaza J., Pomp S., Porras I., Praena J., Quesada J. M., Reifarth R., Rochman D., Romanets Y., Rubbia C., Sánchez-Caballero A., Sabaté-Gilarte M., Schillebeeckx P., Schumann D., Sekhar A., Smith A. G., Sosnin N. V., Stamati M. E., Sturniolo A., Tagliente G., Tarrío D., Torres-Sánchez P., Vagena E., Valenta S., Variale V., Vaz P., Vecchio G., Vescovi D., Vlachoudis V., Vlastou R., Wallner A., Woods P. J., Wright T., Zarrella R., and Žugec P.

Subjects
Physics, QC1-999
Abstract

Radiative neutron-capture cross sections are of pivotal importance in many fields such as nucle-osynthesis studies or innovative reactor technologies. A large number of isotopes have been measured with high accuracy, but there are still a large number of relevant isotopes whose cross sections could not be experimentally determined yet, at least with sufficient accuracy and completeness, owing to limitations in detection techniques, sample production methods or in the facilities themselves. In the context of the HYMNS (High-sensitivitY Measurements of key stellar Nucleo-Synthesis reactions) project over the last six years we have developed a novel detection technique aimed at background suppression in radiative neutron-capture time-of-flight measurements. This new technique utilizes a complex detection set-up based on position-sensitive radiation-detectors deployed in a Compton-camera array configuration. The latter enables to implement gamma-ray imaging techniques, which help to disentangle true capture events arising from the sample under study and contaminant background events from the surroundings. A summary on the main developments is given in this contribution together with an update on recent experiments at CERN n_TOF and an outlook on future steps.

Published
2023
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33. High resolution 80Se(n,γ) cross section measurement at CERN n_TOF

Author

Babiano-Suarez V., Balibrea-Correa J., Caballero-Ontanaya L., Domingo-Pardo C., Ladarescu I., Lerendegui-Marco J., Tain J. L., Calviño F., Casanovas A., Tarifeño-Saldivia A., Guerrero C., Aberle O., Alcayne V., Amaducci S., Andrzejewski J., Audouin L., Bacak M., Barbagallo M., Bennett S., Berthoumieux E., Billowes J., Bosnar D., Brown A., Busso M., Caamaño M., Calviani M., Cano-Ott D., Cerutti F., Chiaveri E., Colonna N., Cortés G., Cortés-Giraldo M. A., Cosentino L., Cristallo S., Damone L. A., Davies P. J., Diakaki M., Dietz M., Dressler R., Ducasse Q., Dupont E., Durán I., Eleme Z., Fernández-Domínguez B., Ferrari A., Finocchiaro P., Furman V., Göbel K., Garg R., Gawlik-Ramięga A., Gilardoni S., Gonçalves I. F., González-Romero E., Gunsing F., Harada H., Heinitz S., Heyse J., Jenkins D. G., Junghans A., Käppeler F., Kadi Y., Kimura A., Knapová I., Kokkoris M., Kopatch Y., Krtička M., Kurtulgil D., Lederer-Woods C., Leeb H., Lonsdale S. J., Macina D., Manna A., Martínez T., Masi A., Massimi C., Mastinu P., Mastromarco M., Maugeri E. A., Mazzone A., Mendoza E., Mengoni A., Michalopoulou V., Milazzo P. M., Mingrone F., Moreno-Soto J., Musumarra A., Negret A., Nolte R., Ogállar F., Oprea A., Patronis N., Pavlik A., Perkowski J., Persanti L., Petrone C., Pirovano E., Porras I., Praena J., Quesada J. M., Ramos-Doval D., Rauscher T., Reifarth R., Rochman D., Romanets Y., Rubbia C., Sabaté-Gilarte M., Saxena A., Schillebeeckx P., Schumann D., Sekhar A., Smith A. G., Sosnin N. V., Sprung P., Stamatopoulos A., Tagliente G., Tassan-Got L., Thomas Th., Torres-Sánchez P., Tsinganis A., Ulrich J., Urlass S., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Vescovi D., Vlachoudis V., Vlastou R., Wallner A., Woods P. J., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

Neutron capture cross section measurements of isotopes close to s-process branching-points are of fundamental importance for the understanding of this nucleosynthesis mechanism through which about 50% of the elements heavier than iron are produced. We present in this contribution the results corresponding to the high resolution measurement, for first time ever, of the 80Se(n, γ) cross section, in which 98 resonances never measured before have been reported. As a consequence, ten times more precise values for the MACS have been obtained compared to previous accepted value adopted in the astrophysical KADoNiS data base.

Published
2023
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34. Neutron capture and total cross-section measurements on 94,95,96Mo at n_TOF and GELINA

Author

Mucciola R., Paradela C., Manna A., Alaerts G., Massimi C., Kopecky S., Mengoni A., Moens A., Schillebeeckx P., Wynants R., Aberle O., Alcayne V., Altieri S., Amaducci S., Amar Es-Sghir H., Andrzejewski J., Babiano-Suarez V., Bacak M., Balibrea J., Bennett S., Bernardes A. P., Berthoumieux E., Bosnar D., Busso M., Caamaño M., Calviño F., Calviani M., Cano-Ott D., Casanovas A., Castelluccio D. M., Cerutti F., Cescutti G., Chasapoglou S., Chiaveri E., Colombetti P., Colonna N., Console Camprini P. C., Cortés G., Cortés-Giraldo M. A., Cosentino L., Cristallo S., Di Castro M., Diacono D., Diakaki M., Dietz M., Domingo-Pardo C., Dressler R., Dupont E., Durán I., Eleme Z., Fargier S., Fernández-Domínguez B., Finocchiaro P., Fiore S., Furman V., García-Infantes F., Gawlik-Ramięga A., Gervino G., Gilardoni S., González-Romero E., Guerrero C., Gunsing F., Gustavino C., Heyse J., Jenkins D. G., Jericha E., Junghans A., Kadi Y., Katabuchi T., Knapová I., Kokkoris M., Kopatch Y., Krtička M., Kurtulgil D., Ladarescu I., Lederer-Woods C., Lerendegui-Marco J., Lerner G., Martínez T., Masi A., Mastinu P., Mastromarco M., Matteucci F., Maugeri E. A., Mazzone A., Mendoza E., Michalopoulou V., Milazzo P. M., Murtas† F., Musacchio-Gonzalez E., Musumarra A., Negret A., Oprea A., Pérez-Maroto P., Patronis N., Pavón-Rodríguez J. A., Pellegriti M. G., Perkowski J., Petrone C., Piersanti L., Pirovano E., Pomp S., Porras I., Praena J., Protti N., Quesada J. M., Rauscher T., Reifarth R., Rochman D., Romanets Y., Romano F., Rubbia C., Sánchez A., Sabaté-Gilarte M., Schumann D., Sekhar A., Smith A. G., Sosnin N. V., Spelta M., Stamati M. E., Tagliente G., Tarifeño-Saldivia A., Tarrío D., Terranova N., Torres-Sánchez P., Urlass S., Valenta S., Variale V., Vaz P., Vescovi D., Vlachoudis V., Vlastou R., Wallner A., Woods P. J., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

Capture and total cross section measurements for 94,95,96Mo have been performed at the neutron time-of-flight facilities, n_TOF at CERN and GELINA at JRC-Geel. The measurements were performed using isotopically enriched samples with an enrichment above 95% for each of the 94,95,96Mo isotopes. The capture measurements were performed at n_TOF using C6D6 detectors and a new sTED detector. The transmission measurements were performed at a 10 m station of GELINA using a 6Li glass neutron detector. Preliminary results of these measurements are presented.

Published
2023
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35. Measurement of the 235U(n,f) cross section relative to the 10B(n,α) reaction with Micromegas detectors at the CERN n_TOF facility: First results

Author

Michalopoulou Veatriki, Diakaki Maria, Vlastou Rosa, Kokkoris Michael, Stamatopoulos Athanasios, Tsinganis Andrea, Eleme Zinovia, Patronis Nikolas, Heyse Jan, Schillebeeckx Peter, Tassan-Got Laurent, Barbagallo Massimo, Colonna Nicola, Urlass Sebastian, Macina Daniela, Chiaveri Enrico, Aberle Oliver, Alcayne Victor, Amaducci Simone, Andrzejewski Józef, Audouin Laurent, Babiano-Suarez Victor, Bacak Michael, Bennett Samuel, Berthoumieux Eric, Billowes Jon, Bosnar Damir, Brown Adam, Busso Maurizio, Caamaño Manuel, Caballero-Ontanaya Luis, Calviño Francisco, Calviani Marco, Cano-Ott Daniel, Casanovas Adria, Cerutti Francesco, Cortés Guillem, Cortés-Giraldo Miguel, Cosentino Luigi, Cristallo Sergio, Damone Lucia-Anna, Davies Paul-John, Dietz Mirco, Domingo-Pardo César, Dressler Rugard, Ducasse Quentin, Dupont Emmeric, Durán Ignacio, Fernández-Domínguez Beatriz, Ferrari Alfredo, Finocchiaro Paolo, Göbel Kathrin, Garg Ruchi, Gawlik-Ramięga Aleksandra, Gilardoni Simone, Gonçalves Isabel, González-Romero Enrique, Guerrero Carlos, Gunsing Frank, Harada Hideo, Heinitz Stephan, Jenkins David, Junghans Arnd, Käppeler† Franz, Kadi Yacine, Kimura Atsushi, Knapová Ingrid, Krtička Milan, Kurtulgil Deniz, Ladarescu Ion, Lederer-Woods Claudia, Leeb Helmut, Lerendegui-Marco Jorge, Lonsdale Sarah-Jane, Manna Alice, Martínez Trinitario, Masi Alessandro, Massimi Cristian, Mastinu Pierfrancesco, Mastromarco Mario, Maugeri Emilio-Andrea, Mazzone Annamaria, Mendoza Emilio, Mengoni Alberto, Milazzo Paolo, Mingrone Federica, Moreno-Soto Javier, Musumarra Agatino, Negret Alexandru, Nolte Ralf, Ogállar Francisco, Oprea Andreea, Pavlik Andreas, Perkowski Jarosław, Piersanti Luciano, Petrone Cristina, Pirovano Elisa, Porras Ignacio, Praena Javier, Quesada José-Manuel, Ramos-Doval Diego, Rauscher Thomas, Reifarth René, Rochman Dimitri, Rubbia Carlo, Sabaté-Gilarte Marta, Saxena Alok, Schumann Dorothea, Sekhar Adhitya, Smith Gavin, Sosnin Nikolay, Sprung Peter, Tagliente Giuseppe, Tain José, Tarifeño-Saldivia Ariel, Thomas Benedikt, Torres-Sánchez Pablo, Ulrich Jiri, Valenta Stanislav, Vannini Gianni, Variale Vincenzo, Vaz Pedro, Ventura Alberto, Vescovi Diego, Vlachoudis Vasilis, Wallner Anton, Woods Philip-John, Wright Tobias, and Žugec Petar

Subjects
Physics, QC1-999
Abstract

Neutron cross section measurements are often made relative to a neutron cross section standard. Thus, the accuracy of the neutron standards determines the best possible accuracy of the neutron measurements. The 235U(n,f) cross section is widely used as reference, while it is considered a standard at thermal point and between 0.15 to 200 MeV. For this reason, additional cross section data for the 235U(n,f) reaction are useful in order to improve the accuracy and to extend the energy range of the standard. In this work, preliminary results of the measurement of the 235U(n,f) cross-section relative to the standard 10B(n,a) reaction are presented. The high accuracy measurement was performed at the experimental area EAR-1 of the n_TOF facility at CERN, aiming at covering the energy range from the thermal region up to approximately 100 keV. The samples were produced at JRC-Geel in Belgium, while the experimental setup was based on Micromegas detectors.

Published
2023
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36. A segmented total energy detector (sTED) for (n, γ) cross section measurements at n_TOF EAR2

Author

Alcayne V., Cano-Ott D., Garcia J., González-Romero E., Martínez T., Mendoza E., Sánchez A., Plaza J., Balibrea-Correa J., Casanovas A., Domingo-Pardo C., Lerendegui-Marco J., Aberle O., Altieri S., Amaducci S., Amar Es-Sghir H., Andrzejewski J., Babiano-Suarez V., Bacak M., Balibrea J., Bennett S., Bernardes A. P., Berthoumieux E., Bosnar D., Busso M., Caamaño M., Calviño F., Calviani M., Castelluccio D. M., Cerutti F., Cescutti G., Chasapoglou S., Chiaveri E., Colombetti P., Colonna N., Console Camprini P. C., Cortés G., Cortés-Giraldo M. A., Cosentino L., Cristallo S., Di Castro M., Diacono D., Diakaki M., Dietz M., Dressler R., Dupont E., Durán I., Eleme Z., Fargier S., Fernández-Domínguez B., Finocchiaro P., Fiore S., Furman V., García-Infantes F., Gawlik-Ramięga A., Gervino G., Gilardoni S., Guerrero C., Gunsing F., Gustavino C., Heyse J., Jenkins D. G., Jericha E., Junghans A., Kadi Y., Katabuchi T., Knapová I., Kokkoris M., Kopatch Y., Krtička M., Kurtulgil D., Ladarescu I., Lederer-Woods C., Lerner G., Manna A., Masi A., Massimi C., Mastinu P., Mastromarco M., Matteucci F., Maugeri E. A., Mazzone A., Mengoni A., Michalopoulou V., Milazzo P. M., Mucciola R., Murtas† F., Musacchio-Gonzalez E., Musumarra A., Negret A., Oprea A., Pérez-Maroto P., Patronis N., Pavón-Rodríguez J. A., Pellegriti M. G., Perkowski J., Petrone C., Piersanti L., Pirovano E., Pomp S., Porras I., Praena J., Protti N., Quesada J. M., Rauscher T., Reifarth R., Rochman D., Romanets Y., Romano F., Rubbia C., Sabaté-Gilarte M., Schillebeeckx P., Schumann D., Sekhar A., Smith A. G., Sosnin N. V., Spelta M., Stamati M. E., Tagliente G., Tarifeño-Saldivia A., Tarrío D., Terranova N., Torres-Sánchez P., Urlass S., Valenta S., Variale V., Vaz P., Vescovi D., Vlachoudis V., Vlastou R., Wallner A., Woods P. J., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The neutron time-of-flight facility n_TOF is characterised by its high instantaneous neutron intensity, high-resolution and broad neutron energy spectra, specially conceived for neutron-induced reaction cross section measurements. Two Time-Of-Flight (TOF) experimental areas are available at the facility: experimental area 1 (EAR1), located at the end of the 185 m horizontal flight path from the spallation target, and experimental area 2 (EAR2), placed at 20 m from the target in the vertical direction. The neutron fluence in EAR2 is ˜ 300 times more intense than in EAR1 in the relevant time-of-flight window. EAR2 was designed to carry out challenging cross-section measurements with low mass samples (approximately 1 mg), reactions with small cross-sections or/and highly radioactive samples. The high instantaneous fluence of EAR2 results in high counting rates that challenge the existing capture systems. Therefore, the sTED detector has been designed to mitigate these effects. In 2021, a dedicated campaign was done validating the performance of the detector up to at least 300 keV neutron energy. After this campaign, the detector has been used to perform various capture cross section measurements at n_TOF EAR2.

Published
2023
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37. The n_TOF NEAR Station Commissioning and first physics case

Author

Stamati M. E., Torres-Sánchez P., Pérez-Maroto P., Cecchetto M., Goula S., Mastromarco M., Chasapoglou S., Beltrami C., Chiesa D., Manna A., Mucciola R., Patronis N., Praena J., Guerrero C., Colonna N., Mengoni A., Massimi C., Aberle O., Alcayne V., Altieri S., Amaducci S., Amar Es-Sghir H., Andrzejewski J., Babiano-Suarez V., Bacak M., Balibrea J., Bennett S., Bernardes A. P., Berthoumieux E., Bosnar D., Busso M., Caamaño M., Calviño F., Calviani M., Cano-Ott D., Casanovas A., Castelluccio D. M., Cerutti F., Cescutti G., Chiaveri E., Colombetti P., Console Camprini P. C., Cortés G., Cortés-Giraldo M. A., Cosentino L., Cristallo S., Di Castro M., Diacono D., Diakaki M., Dietz M., Domingo-Pardo C., Dressler R., Dupont E., Durán I., Eleme Z., Fargier S., Fernández-Domínguez B., Finocchiaro P., Fiore S., Furman V., García-Infantes F., Gawlik-Ramięga A., Gervino G., Gilardoni S., González-Romero E., Gunsing F., Gustavino C., Heyse J., Jenkins D. G., Jericha E., Junghans A., Kadi Y., Katabuchi T., Knapová I., Kokkoris M., Kopatch Y., Krticka M., Kurtulgil D., Ladarescu I., Lederer-Woods C., Lerendegui-Marco J., Lerner G., Martínez T., Masi A., Mastinu P., Matteucci F., Maugeri E. A., Mazzone A., Mendoza E., Michalopoulou V., Milazzo P. M., Murtas F., Musacchio-Gonzalez E., Musumarra A., Negret A., Oprea A., Pavón-Rodríguez J. A., Pellegriti M. G., Perkowski J., Petrone C., Piersanti L., Pirovano E., Pomp S., Porras I., Protti N., Quesada J. M., Rauscher T., Reifarth R., Rochman D., Romanets Y., Romano F., Rubbia C., Sánchez A., Sabaté-Gilarte M., Schillebeeckx P., Schumann D., Sekhar A., Smith A. G., Sosnin N. V., Spelta M., Tagliente G., Tarifeño-Saldivia A., Taríro D., Terranova N., Urlass S., Valenta S., Variale V., Vaz P., Vescovi D., Vlachoudis V., Vlastou R., Wallner A., Woods P. J., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The NEAR Station is a new experimental area developed at the n_TOF Facility at CERN. The activation station of NEAR underwent a characterization of the beam following the installation of the new n_TOF Spallation Target. The commissioning of the neutron beam comprises a set of simulations made with the FLUKA code and experimental verification. The experimental determination of the neutron spectrum was made using activation techniques with three separate set-ups. Two set-ups were based on the Multi-foil Activation technique (MAM-1 and MAM-2), and the third set-up relied on the process of neutron moderation and activation of a single material (ANTILoPE). The three set-ups are presented. Also the present plans and future perspectives of the activation station of NEAR are discussed.

Published
2023
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38. Characterisation of the n_TOF 20 m beam line at CERN with the new spallation target

Author

Pavón-Rodríguez J. A., Alcayne V., Amaducci S., Bacak M., Casanovas A., Cortés-Giraldo M. A., García-Infantes F., Lerendegui-Marco J., Manna A., Musacchio-Gonzalez E., Patronis N., Sabaté-Gilarte M., Stamati M. E., Tassan-Got L., Vlachoudis V., Aberle O., Altieri S., Amar Es-Sghir H., Andrzejewski J., Babiano-Suarez V., Balibrea J., Bennett S., Bernardes A. P., Berthoumieux E., Bosnar D., Busso M., Caamaño M., Alviño F., Calviani M., Cano-Ott D., Castelluccio D. M., Cerutti F., Cescutti G., Chasapoglou S., Chiaveri E., Colombetti P., Colonna N., Console Camprini P. C., Cortés G., Cosentino L., Cristallo S., Di Castro M., Diacono D., Diakaki M., Dietz M., Domingo-Pardo C., Dressler R., Dupont E., Durán I., Eleme Z., Fargier S., Fernández-Domínguez B., Finocchiaro P., Fiore S., Furman V., Gawlik-Ramięga A., Gervino G., Gilardoni S., González-Romero E., Guerrero C., Gunsing F., Gustavino C., Heyse J., Jenkins D. G., Jericha E., Junghans A., Kadi Y., Katabuchi T., Knapová I., Kokkoris M., Kopatch Y., Krtička M., Kurtulgil D., Ladarescu I., Lederer-Woods C., Lerner G., Martínez T., Masi A., Massimi C., Mastinu P., Mastromarco M., Matteucci F., Maugeri E. A., Mazzone A., Mendoza E., Mengoni A., Michalopoulou V., Milazzo P. M., Mucciola R., Murtas† F., Musumarra A., Negret A., Oprea A., Pérez-Maroto P., Pellegriti M. G., Perkowski J., Petrone C., Piersanti L., Pirovano E., Pomp S., Porras I., Praena J., Protti N., Quesada J. M., Rauscher T., Reifarth R., Rochman D., Romanets Y., Romano F., Rubbia C., Sánchez A., Schillebeeckx P., Schumann D., Sekhar A., Smith A. G., Sosnin N. V., Spelta M., Tagliente G., Tarifeño-Saldivia A., Tarrío D., Terranova N., Torres-Sánchez P., Urlass S., Valenta S., Variale V., Vaz P., Vescovi D., Vlastou R., Wallner A., Woods P. J., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The n_TOF facility hosts CERN’s pulsed neutron source, comprising two beam lines of different flight paths and one activation station. It is based on a proton beam delivered by the PS accelerator impinging on a lead spallation target. During Long Shutdown 2 (LS2) at CERN (2019-2021), a major upgrade of the spallation target was carried out in order to optimize the performances of the neutron beam. Therefore, the characteristics of n_TOF two experimental areas were investigated in detail. In this work, the focus is on the second experimental area (EAR2), located 20 m above the spallation target. Preliminary results of the neutron energy distribution and beam line energy resolution are presented, compared to previous experimental campaigns and Monte Carlo simulations with the FLUKA code. Moreover, preliminary results of the spatial beam profile measurements are shown.

Published
2023
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39. First high resolution measurement of neutron capture resonances in 176Yb at the n_TOF CERN facility

Author

García-Infantes F., Praena J., Casanovas A., Mastromarco M., Aberle O., Alcayne V., Altieri S., Amaducci S., Amar Es-Sghir H., Andrzejewski J., Babiano-Suarez V., Bacak M., Balibrea J., Bennett S., Bernardes A.P., Berthoumieux E., Bosnar D., Busso M., Caamaño M., Calviño F., Calviani M., Cano-Ott D., Castelluccio D.M., Cerutti F., Cescutti G., Chasapoglou S., Chiaveri E., Colombetti P., Colonna N., Console Camprini P.C., Coréts G., Cortés-Giraldo M.A., Cosentino L., Cristallo S., Di Castro M., Diacono D., Diakaki M., Dietz M., Domingo-Pardo C., Dressler R., Dupont E., Duarn I., Eleme Z., Fargier S., Fernández-Domínguez B., Finocchiaro P., Fiore S., Furman V., Gawlik-Ramięga A., Gervino G., Gilardoni S., González-Romero E., Guerrero C., Gunsing F., Gustavino C., Heyse J., Jenkins D.G., Jericha E., Junghans A., Kadi Y., Katabuchi T., Knapova I., Kokkoris M., Kopatch Y., Krtička M., Kurtulgil D., Ladarescu I., Lederer-Woods C., Lerendegui-Marco J., Lerner G., Manna A., Martínez T., Masi A., Massimi C., Mastinu P., Atteucci F., Maugeri E. A., Mazzone A., Mendoza E., Mengoni A., Michalopoulou V., Milazzo P. M., Mucciola R., Murtas F., Musacchio-Gonzalez E., Musumarra A., Negret A., Oprea A., Pérez-Maroto P., Patronis N., Pavón-Rodríguez J. A., Pellegriti M. G., Perkowski J., Petrone C., Piersanti L., Pirovano E., Pomp S., Porras I., Protti N., Quesada J. M., Rauscher T., Reifarth R., Ochman D., Romanets Y., Romano F., Rubbia C., Sánchez A., Sabaté-Gilarte M., Schillebeeckx P., Schumann D., Sekhar A., Smith A. G., Sosnin N. V., Spelta M., Stamati M. E., Tagliente G., Tarifeño-Saldivia A., Tarrío D., Terranova N., Torres-Sánchez P., Urlass S., Valenta S., Variale V., Vaz P., Vescovi D., Vlachoudis V., Lastou R., Wallner A., Woods P. J., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

Several international agencies recommend the study of new routes and new facilities for producing radioisotopes with application to nuclear medicine. 177Lu is a versatile radioisotope used for therapy and diagnosis (theranostics) of cancer with good success in neuroendocrine tumours that is being studied to be applied to a wider range of tumours. 177Lu is produced in few nuclear reactors mainly by the neutron capture on 176Lu. However, it could be produced at high-intensity celeratorbased neutron facilities. The energy of the neutrons in accelerator-based neutron facilities is higher than in thermal reactors.Thus, experimental data on the 176Yb(n,γ) cross-section in the eV and keV region are mandatory to calculate accurately the production of 177Yb, which beta decays to 177Lu. At present, there are not experimental data available from thermal to 3 keV of the 176Yb(n,γ) cross-section. In addition, there is no data in the resolved resonance region (RRR). This contribution shows the first results of the 176Yb capture measurement performed at the n_TOF facility at CERN.

Published
2023
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40. First measurement of the 94Nb(n,γ) cross section at the CERN n_TOF facility

Author

Balibrea-Correa J., Babiano-Suárez V., Lerendegui-Marco J., Domingo-Pardo C., Ladarescu I., Tarifeño-Saldivia A., Alcayne V., Cano-Ott D., González-Romero E., Martínez T., Mendoza E., Guerrero C., Calviño F., Casanovas A., Köster U., Chiera N. M., Dressler R., Maugeri E. A., Schumann D., Aberle O., Altieri S., Amaducci S., Andrzejewski J., Bacak M., Beltrami C., Bennett S., Bernardes A. P., Berthoumieux E., Beyer R., Boromiza M., Bosnar D., Caamaño M., Calviani M., Cerutti F., Cescutti G., Chiaveri E., Colombetti P., Colonna N., Console Camprini P., Cortés G., Cortés-Giraldo M. A., Cosentino L., Cristallo S., Dellmann S., Di Castro M., Di Maria S., Diakaki M., Dietz M., Dupont E., Durán I., Eleme Z., Fargier S., Fernández B., Fernández-Domínguez B., Finocchiaro P., Fiore S., García-Infantes F., Gawlik-Ramięga A., Gervino G., Gilardoni S., Gunsing F., Gustavino C., Heyse J., Hillman W., Jenkins D. G., Jericha E., Junghans A., Kadi Y., Kaperoni K., Kaur G., Kimura A., Knapová I., Kokkoris M., Krtička M., Kyritsis N., Lederer-Woods C., Lerner G., Manna A., Masi A., Massimi C., Mastinu P., Mastromarco M., Mazzone A., Mengoni A., Michalopoulou V., Milazzo P. M., Mucciola R., Murtas F., Musacchio-Gonzalez E., Musumarra A., Negret A., Pérez de Rada A., Pérez-Maroto P., Patronis N., Pavón-Rodríguez J. A., Pellegriti M. G., Perkowski J., Petrone C., Pirovano E., Plaza J., Pomp S., Porras I., Praena J., Quesada J. M., Reifarth R., Rochman D., Romanets Y., Rubbia C., Sánchez-Caballero A., Sabaté-Gilarte M., Schillebeeckx P., Sekhar A., Smith A. G., Sosnin N. V., Stamati M. E., Sturniolo A., Tagliente G., Tarrío D., Torres-Sánchez P., Vagena E., Valenta S., Variale V., Vaz P., Vecchio G., Vescovi D., Vlachoudis V., Vlastou R., Wallner A., Woods P. J., Wright T., Zarrella R., and Žugec P.

Subjects
Physics, QC1-999
Abstract

One of the crucial ingredients for the improvement of stellar models is the accurate knowledge of neutron capture cross-sections for the different isotopes involved in the s-,r- and i- processes. These measurements can shed light on existing discrepancies between observed and predicted isotopic abundances and help to constrain the physical conditions where these reactions take place along different stages of stellar evolution. In the particular case of the radioactive 94Nb, the 94Nb(n,γ) cross-section could play a role in the determination of the s-process production of 94Mo in AGB stars, which presently cannot be reproduced by state-of-the-art stellar models. There are no previous 94Nb(n,γ) experimental data for the resolved and unresolved resonance regions mainly due to the difficulties in producing highquality samples and also due to limitations in conventional detection systems commonly used in time-of-flight experiments. Motivated by this situation, a first measurement of the 94Nb(n,γ) reaction was carried out at CERN n_TOF, thereby exploiting the high luminosity of the EAR2 area in combination with a new detection system of small-volume C6D6-detectors and a high quality 94Nb-sample. The latter was based on hyper-pure 93Nb material activated at the high-flux reactor of ILL-Grenoble. An innovative ring-configuration detection system in close geometry around the capture sample allowed us to significantly enhance the signal-to-background ratio. This set-up was supplemented with two conventional C6D6-detectors and a highresolution LaCl3(Ce)-detector, which will be employed for addressing reliably systematic effects and uncertainties. At the current status of the data analysis, 18 resonance in 94Nb+n have been observed for the first time in the neutron energy range from thermal up to 10 keV.

Published
2023
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41. Neutron-induced cross section measurements

Author

Massimi C., Aberle O., Alcayne V., Altieri S., Amaducci S., Andrzejewski J., Babiano-Suarez V., Bacak M., Balibrea J., Beltrami C., Bennett S., Bernardes A. P., Berthoumieux E., Boromiza M., Bosnar D., Caamaño M., Calviño F., Calviani M., Cano-Ott D., Casanovas A., Castelluccio D. M., Cerutti F., Cescutti G., Chasapoglou S., Chiaveri E., Colombetti P., Colonna N., Console Camprini P., Cortés G., Cortés-Giraldo M. A., Cosentino L., Cristallo S., Dellmann S., Di Castro M., Di Maria S., Diakaki M., Dietz M., Domingo-Pardo C., Dressler R., Dupont E., Durán I., Eleme Z., Fargier S., Fernández B., Fernández-Domínguez B., Finocchiaro P., Fiore S., Furman V., GarcíaInfantes F., Gawlik-Ramięga A., Gervino G., Gilardoni S., González-Romero E., Guerrero C., Gunsing F., Gustavino C., Heyse J., Hillman W., Jenkins D. G., Jericha E., Junghans A., Kadi Y., Kaperoni K., Kaur G., Kimura A., Knapová I., Kokkoris M., Kopatch Y., Krtička M., Kyritsis N., Ladarescu I., Lederer-Woods C., Lerendegui-Marco J., Lerner G., Manna A., Martínez T., Masi A., Mastinu P., Mastromarco M., Maugeri E. A., Mazzone A., Mendoza E., Mengoni A., Michalopoulou V., Milazzo P. M., Mucciola R., Murtas F., Musacchio-Gonzalez E., Musumarra A., Negret A., Pérez de Rada A., Pérez-Maroto P., Patronis N., Pavón-Rodríguez J. A., Pellegriti M. G., Perkowski J., Petrone C., Pirovano E., Plaza J., Pomp S., Porras I., Praena J., Quesada J. M., Reifarth R., Rochman D., Romanets Y., Rubbia C., Sánchez A., Sabaté-Gilarte M., Schillebeeckx P., Schumann D., Sekhar A., Smith A. G., Sosnin N. V., Stamati M. E., Sturniolo A., Tagliente G., Tarrío D., Torres-Sánchez P., Urlass S., Vagena E., Valenta S., Variale V., Vaz P., Vecchio G., Vescovi D., Vlachoudis V., Vlastou R., Wallner A., Woods P. J., Wright T., Zarrella R., and Žugec P.

Subjects
Physics, QC1-999
Abstract

Neutron-induced cross sections represent the main nuclear input to models of stellar and Big-Bang nucleosynthesis. While (n,γ) reactions are relevant for the formation of elements heavier than iron, (n,p) and (n,α) reactions can play an important role in specific cases. The time-of-flight method is routinely used at n_TOF to experimentally determine the cross section data. In addition, recent upgrades of the facility will allow the use of activation techniques as well, possibly opening the way to a systematic study of neutron interaction with radioactive isotopes. In the last 20 years n_TOF has provided a large amount of experimental data for Nuclear Astrophysics. Our plan is to carry on challenging measurements and produce nuclear data in the next decades as well.

Published
2023
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42. New detection systems for an enhanced sensitivity in key stellar (n,γ) measurements

Author

Lerendegui-Marco J., Babiano-Suárez V., Balibrea-Correa J., Domingo-Pardo C., Ladarescu I., Tarifeño-Saldivia A., Alcayne V., Cano-Ott D., González-Romero E., Martínez T., Mendoza E., Guerrero C., Calviño F., Casanovas A., Köster U., Chiera N. M., Dressler R., Maugeri E. A., Schumann D., Aberle O., Altieri S., Amaducci S., Andrzejewski J., Bacak M., Beltrami C., Bennett S., Bernardes A. P., Berthoumieux E., Beyer R., Boromiza M., Bosnar D., Caamaño M., Calviani M., Cerutti F., Cescutti G., Chiaveri E., Colombetti P., Colonna N., Console Camprini P., Cortés G., Cortés-Giraldo M. A., Cosentino L., Cristallo S., Dellmann S., Di Castro M., Di Maria S., Diakaki M., Dietz M., Dupont E., Durán I., Eleme Z., Fargier S., Fernández B., Fernández-Domínguez B., Finocchiaro P., Fiore S., García-Infantes F., Gawlik-Ramięga A., Gervino G., Gilardoni S., Gunsing F., Gustavino C., Heyse J., Hillman W., Jenkins D. G., Jericha E., Junghans A., Kadi Y., Kaperoni K., Kaur G., Kimura A., Knapová I., Kokkoris M., Krtička M., Kyritsis N., Lederer-Woods C., Lerner G., Manna A., Masi A., Massimi C., Mastinu P., Mastromarco M., Mazzone A., Mengoni A., Michalopoulou V., Milazzo P. M., Mucciola R., Murtas F., Musacchio-Gonzalez E., Musumarra A., Negret A., Pérez de Rada A., Pérez-Maroto P., Patronis N., Pavón-Rodríguez J. A., Pellegriti M. G., Perkowski J., Petrone C., Pirovano E., Plaza J., Pomp S., Porras I., Praena J., Quesada J. M., Reifarth R., Rochman D., Romanets Y., Rubbia C., Sánchez-Caballero A., Sabaté-Gilarte M., Schillebeeckx P., Sekhar A., Smith A. G., Sosnin N. V., Stamati M. E., Sturniolo A., Tagliente G., Tarrío D., Torres-Sánchez P., Vagena E., Valenta S., Variale V., Vaz P., Vecchio G., Vescovi D., Vlachoudis V., Vlastou R., Wallner A., Woods P. J., Wright T., Zarrella R., and Žugec P.

Subjects
Physics, QC1-999
Abstract

Neutron capture cross-section measurements are fundamental in the study of astrophysical phenomena, such as the slow neutron capture (s-) process of nucleosynthesis operating in red-giant and massive stars. However, neutron capture measurements via the time-of-flight (TOF) technique on key s-process nuclei are often challenging. Difficulties arise from the limited mass (∼mg) available and the high sample-related background in the case of the unstable s-process branching points. Measurements on neutron magic nuclei, that act as s-process bottlenecks, are affected by low (n,γ) cross sections and a dominant neutron scattering background. Overcoming these experimental challenges requires the combination of facilities with high instantaneous flux, such as n_TOFEAR2, with detection systems with an enhanced detection sensitivity and high counting rate capabilities. This contribution reviews some of the latest detector developments in detection systems for (n,γ) measurements at n_TOF, such as i-TED, an innovative detection system which exploits the Compton imaging technique to reduce the dominant neutron scattering background and s-TED, a highly segmented total energy detector intended for high flux facilities. The discussion will be illustrated with results of the first measurement of key the s-process branching-point reaction 79Se(n,γ).

Published
2023
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43. Climate Change Perceptions: A Study with Portuguese University Social Education Students

Author

Ricardo Ramos, Paula Vaz, Maria José Rodrigues, and Isilda Rodrigues

Abstract

Climate change (CC) is one of the most urgent problems to solve in this century, the effects of which cover a wide range of disciplines that go beyond the environmental component, becoming a social and economic problem as well. Social educators are professionals who must ensure that the quality of life in socially vulnerable societies is improved. In order to mitigate the problem of climate change, it is necessary for all professionals in the most varied areas to have climate literacy, so that they can adopt behaviors that comply with the objectives of sustainable development. Recognizing the importance of the social educator in the context of contemporary societies, we intended to find out the university students' perceptions on the social education course. With this in mind, we set out to carry out this study, which was based on the application of a questionnaire using a Likert scale. The respondents were 161 social education students at a higher education institution in Portugal. In order to carry out the inferential analysis, we took care to meet the necessary criteria for carrying out parametric tests. The results showed that a majority (72.6 %) of students were concerned about climate change. They (54.7 %) also stated that they would like their course to deal more with climate change, as 74 % acknowledged that they did not have the skills to deal with climate change as a future professional. The results also showed that the students were incapable of correctly listing a consequence of climate change. The data collected and analyzed in this study allowed us to conclude that Environmental Education played a fundamental role in the academic training of social educators, suggesting the need for its reinforcement and inclusion in their training plans. We also found that greater efforts were needed to improve students' climate literacy.

Published
2024
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44. What characteristics define disinformation and fake news?: review of taxonomies and definitions

Author

Silva, Ergon Cugler de Moraes and Vaz, Jose Carlos

Subjects
Computer Science - Computers and Society, Computer Science - Information Theory
Abstract

What characteristics define disinformation and fake news? To address this research question, this Technical Note provides a comprehensive analysis of disinformation and fake news, synthesizing 46 definitions and highlighting four key points addressing their fundamental characteristics. Adopting the Prisma 2020 method, five search sets with the Boolean operator AND were selected in both Portuguese and English, which were applied across four databases, resulting in 237 reviewed articles. Following a meticulous analysis, relevant articles were identified and included, while duplicates and inaccessible documents were excluded. It points to disinformation as information that is totally or partially false, crafted by a sender with the aim of misleading, with opportunistic content designed to manipulate reality, being amplified by individual characteristics of the receiver in their interpretation and by contextual factors in which they are embedded. This Technical Note seeks to contribute to an understanding of the phenomenon of disinformation that includes the contextual dimension, obtaining as fundamental elements of analysis: I.) Sender; II.) Content; III.) Receiver; and IV.) Environment.

Published
2024

45. A modular and scalable web platform for computational phylogenetics

Author

Brandão, Nyckollas, Jesus, André, Páscoa, André, Francisco, Alexandre P., Ramirez, Mário, and Vaz, Cátia

Subjects
Quantitative Biology - Populations and Evolution, Computer Science - Social and Information Networks
Abstract

Phylogenetic analysis, which allow to understand the evolution of bacterial and viral epidemics, requires large quantities of data to be analysed and processed for knowledge extraction. One of the major challenges consists on the integration of the results from typing and phylogenetic inference methods with epidemiological data, namely in what concerns their integrated and simultaneous analysis and visualization. Numerous approaches to support phylogenetic analysis have been proposed, varying from standalone tools to integrative web applications that include tools and/or algorithms for executing the common analysis tasks for this kind of data. However, most of them lack the capacity to integrate epidemiological data. Others provide the ability for visualizing and analyzing such data, allowing the integration of epidemiological data but they do not scale for large data analysis and visualization. Namely, most of them run inference and/or visualization optimization tasks on the client side, which becomes often unfeasible for large amounts of data, usually implying transferring data from existing databases in order to be analysed. Moreover, the results and optimizations are not stored for reuse. We propose the PHYLOViZ Web Platform, a cloud based tool for phylogenetic analysis, that not only unifies the features of both existing versions of PHYLOViZ, but also supports structured and customized workflows for executing data processing and analyses tasks, and promotes the reproducibility of previous phylogenetic analyses. This platform supports large scale analyses by relying on a workflow system that enables the distribution of parallel computations on cloud and HPC environments. Moreover, it has a modular architecture, allowing easy integration of new methods and tools, as well as customized workflows, making it flexible and extensible., Comment: 12 pages, 5 figures

Published
2024

46. Asymptotics in infinite monoidal categories

Author

Lacabanne, Abel, Tubbenhauer, Daniel, and Vaz, Pedro

Subjects
Mathematics - Category Theory, Mathematics - Combinatorics, Mathematics - Representation Theory, Primary: 11N45, 18M05, Secondary: 05C81, 15A18, 20C20
Abstract

We discuss formulas for the asymptotic growth rate of the number of summands in tensor powers in certain (finite or infinite) monoidal categories. Our focus is on monoidal categories with infinitely many indecomposable objects, with our main tools being generalized Perron-Frobenius theory alongside techniques from random walks., Comment: 19 pages, many figures, comments welcome

Published
2024

47. XFLEX HYDRO demonstrators grid services assessment and Ancillary Services Matrix elaboration

Author

Nicolet, Christophe, Dreyer, Matthieu, Landry, Christian, Alligné, Sébastien, Béguin, Antoine, Vaillant, Yves, Tobler, Stefan, Sari, Goekhan, Païs, Grégory, Bianciotto, Matteo, Sawyer, Steve, Taylor, Richard, Castro, Manuel Vaz, Vasconcelos, Maria Helena, and Moreira, Carlos

Subjects
Electrical Engineering and Systems Science - Systems and Control
Abstract

This paper presents the methodology and key results which enabled to establish the so-called Ancillary Service Matrix (ASM) presenting the ability to deliver the different ancillary services of each of the 6 demonstrators of the XFLEX HYDRO research project combined with the applicable technologies studied in this analysis. These technologies include i) the variable speed technology with Doubly Fed Induction Machine (DFIM) or Full Size Frequency Converters (FSFC), ii) the Smart Power Plant Supervisor (SPPS) enabling to extend the operating range of the hydraulic units in turbine mode based on a better knowledge of the hydro unit wear and tear and associated costs over the full unit operating range, iii) the hydraulic short circuit (HSC) operation leading to simultaneous operation of pump and turbines of Pumped Storage Power Plants (PSPP) and iv) the Hydro-Battery-Hybrid (HBH) applied at Run-of-River demonstrator. The demonstrators considered for this study includes 4 pumped storage power plants, 1 conventional hydro storage plant and 1 run-of-the-river plant. For each demonstrator a 1D simulation model was developed and validated and was further enhanced to include the model of control system enabling to address the various ancillary services. The systematic 1D numerical simulation of ancillary service contribution of each demonstrator and related technologies enabled to quantify the magnitude of active power response to contribute to the different grid services. The results have been scored between 0 and 5 for each ancillary service, allowing to populate the Ancillary Service Matrix which is summarizing the results in a graphical and synthetic way. The analysis of the score of the Ancillary Services Matrix enables the reader to draw several key conclusions about the benefits unlocked by the implementation of these technologies which are summarized in the paper., Comment: 25 pages, Proceedings of HYDRO 2023, International Conference, October 16-18, 2023, Edinburgh, Scotland

Published
2024

48. Evidence for charge mediated coupling in Fe-Ga/PMN-PT composite multiferroic

Author

Tortarolo, M., Goijman, D., Barral, M. A., Di Napoli, S., Martínez, A. A. Pérez, Ramírez, G., Sarmiento, A., Gómez, J., Zakharova, A., Bayram, S. E., Stramaglia, F., Vaz, C. A. F., Milano, J., and Piamonteze, C.

Subjects
Condensed Matter - Materials Science
Abstract

We present an experimental study of the magnetoelectric coupling (MEC) in the Fe-Ga/PMN-PT thin film multiferroic composite by means of x-ray magnetic circular dichroism (XMCD) and ferromagnetic resonance (FMR). Our measurements show evidence for a charge mediated coupling mechanism, suggested by the asymmetric magnetic remanence (M$_{rem}$) behaviour under opposite electric fields ($\pm$ E) and the asymmetric resonance field (H$_r$) in the FMR measurements. Also, the FMR measurements reveal a perpendicular magnetic anisotropy (PMA), that can be related to an interface charge effect. and it is tunable by E field. Ab initio calculations support the existence of a charge mediated coupling at the Fe-Ga/PMN-PT interface., Comment: 7 pages, 5 figures, Supplemental Material

Published
2024

49. Impact of Employing Weather Forecast Data as Input to the Estimation of Evapotranspiration by Deep Neural Network Models

Author

Vaz, Pedro J., Schütz, Gabriela, Guerrero, Carlos, and Cardoso, Pedro J. S.

Subjects
Computer Science - Artificial Intelligence, Computer Science - Machine Learning
Abstract

Reference Evapotranspiration (ET0) is a key parameter for designing smart irrigation scheduling, since it is related by a coefficient to the water needs of a crop. The United Nations Food and Agriculture Organization, proposed a standard method for ET0 computation (FAO56PM), based on the parameterization of the Penman-Monteith equation, that is widely adopted in the literature. To compute ET0 using the FAO56-PM method, four main weather parameters are needed: temperature, humidity, wind, and solar radiation (SR). One way to make daily ET0 estimations for future days is to use freely available weather forecast services (WFSs), where many meteorological parameters are estimated up to the next 15 days. A problem with this method is that currently, SR is not provided as a free forecast parameter on most of those online services or, normally, such forecasts present a financial cost penalty. For this reason, several ET0 estimation models using machine and deep learning were developed and presented in the literature, that use as input features a reduced set of carefully selected weather parameters, that are compatible with common freely available WFSs. However, most studies on this topic have only evaluated model performance using data from weather stations (WSs), without considering the effect of using weather forecast data. In this study, the performance of authors' previous models is evaluated when using weather forecast data from two online WFSs, in the following scenarios: (i) direct ET0 estimation by an ANN model, and (ii) estimate SR by ANN model, and then use that estimation for ET0 computation, using the FAO56-PM method. Employing data collected from two WFSs and a WS located in Vale do Lobo, Portugal, the latter approach achieved the best result, with a coefficient of determination (R2) ranging between 0.893 and 0.667, when considering forecasts up to 15 days., Comment: A partial version of the work submitted to ESRE/INTERNATIONAL CONFERENCE ON ENVIRONMENTAL SCIENCES AND RENEWABLE ENERGY

Published
2024

50. Neurophotonics beyond the Surface: Unmasking the Brain's Complexity Exploiting Optical Scattering

Author

Xia, Fei, Rimoli, Caio Vaz, Akemann, Walther, Ventalon, Cathie, Bourdieu, Laurent, Gigan, Sylvain, and de Aguiar, Hilton B

Subjects
Physics - Optics, Physics - Biological Physics, Physics - Computational Physics, Physics - Instrumentation and Detectors, Physics - Medical Physics
Abstract

The intricate nature of the brain necessitates the application of advanced probing techniques to comprehensively study and understand its working mechanisms. Neurophotonics offers minimally invasive methods to probe the brain using optics at cellular and even molecular levels. However, multiple challenges persist, especially concerning imaging depth, field of view, speed, and biocompatibility. A major hindrance to solving these challenges in optics is the scattering nature of the brain. This perspective highlights the potential of complex media optics, a specialized area of study focused on light propagation in materials with intricate heterogeneous optical properties, in advancing and improving neuronal readouts for structural imaging and optical recordings of neuronal activity. Key strategies include wavefront shaping techniques and computational imaging and sensing techniques that exploit scattering properties for enhanced performance. We discuss the potential merger of the two fields as well as potential challenges and perspectives toward longer term in vivo applications., Comment: 22 pages, 3 figures, 1 table

Published
2024

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