Artículos (Física Atómica, Molecular y Nuclear)

URI permanente para esta colecciónhttps://hdl.handle.net/11441/10864

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First Joint Oscillation Analysis of Super-Kamiokande Atmospheric and T2K Accelerator Neutrino Data
(American Physical Society, 2025-01-02) Super-Kamiokande Collaboration; T2K Collaboration; Abe, K.; Caballero Carretero, Juan Antonio; Franco Patiño, Juan Manuel; González Rosa, Jesús; Megías Vázquez, Guillermo Daniel; Física Atómica, Molecular y Nuclear
The Super-Kamiokande and T2K Collaborations present a joint measurement of neutrino oscillation parameters from their atmospheric and beam neutrino data. It uses a common interaction model for events overlapping in neutrino energy and correlated detector systematic uncertainties between the two datasets, which are found to be compatible. Using 3244.4 days of atmospheric data and a beam exposure of 19.7(16.3) ×1020 protons on target in (anti)neutrino mode, the analysis finds a 1.9𝜎 exclusion of 𝐶𝑃 conservation (defined as 𝐽𝐶𝑃 =0) and a 1.2𝜎 exclusion of the inverted mass ordering.
Analytical calculation of proton linear energy transfer in voxelized geometries including secondary protons
(IOP Publishing, 2016-02-03) Sanchez-Parcerisa, D.; Cortés Giraldo, Miguel Antonio; Dolney, D.; Kondrla, M.; Fager, M.; Carabe, A.; Física Atómica, Molecular y Nuclear
In order to integrate radiobiological modelling with clinical treatment planning for proton radiotherapy, we extended our in-house treatment planning system FoCa with a 3D analytical algorithm to calculate linear energy transfer (LET) in voxelized patient geometries. Both active scanning and passive scattering delivery modalities are supported. The analytical calculation is much faster than the Monte-Carlo (MC) method and it can be implemented in the inverse treatment planning optimization suite, allowing us to create LET-based objectives in inverse planning. The LET was calculated by combining a 1D analytical approach including a novel correction for secondary protons with pencil-beam type LET-kernels. Then, these LET kernels were inserted into the proton-convolution-superposition algorithm in FoCa. The analytical LET distributions were benchmarked against MC simulations carried out in Geant4. A cohort of simple phantom and patient plans representing a wide variety of sites (prostate, lung, brain, head and neck) was selected. The calculation algorithm was able to reproduce the MC LET to within 6% (1 standard deviation) for low-LET areas (under 1.7 keV μm−1) and within 22% for the high-LET areas above that threshold. The dose and LET distributions can be further extended, using radiobiological models, to include radiobiological effectiveness (RBE) calculations in the treatment planning system. This implementation also allows for radiobiological optimization of treatments by including RBE-weighted dose constraints in the inverse treatment planning process.
GEANT4 simulations of the n TOF spallation source and their benchmarking
(Springer, 2015-12-21) Lo Meo, S.; Cortés Giraldo, Miguel Antonio; Massimi, C.; Lerendegui Marco, Jorge; Barbagallo, M.; Colonna, N.; Guerrero Sánchez, Carlos; Mancusi, D.; Mingrone, F.; Quesada Molina, José Manuel; Sabate-Gilarte, M.; Vannini, G.; Vlachoudis, V.; Física Atómica, Molecular y Nuclear; Ministerio de Economía y Competitividad (MINECO). España
Neutron production and transport in the spallation target of the n_TOF facility at CERN has been simulated with GEANT4. The results obtained with different models of high-energy nucleon-nucleus interaction have been compared with the measured characteristics of the neutron beam, in particular the flux and its dependence on neutron energy, measured in the first experimental area. The best agreement at present, within 20% for the absolute value of the flux, and within few percent for the energy dependence in the whole energy range from thermal to 1 GeV, is obtained with the INCL++ model coupled with the GEANT4 native de-excitation model. All other available models overestimate by a larger factor, of up to 70%, the n_TOF neutron flux. The simulations are also able to accurately reproduce the neutron beam energy resolution function, which is essentially determined by the moderation time inside the target/moderator assembly. The results here reported provide confidence on the use of GEANT4 for simulations of spallation neutron sources.
A critical study of different Monte Carlo scoring methods of dose average linear-energy-transfer maps calculated in voxelized geometries irradiated with clinical proton beams
(IOP Publishing, 2015-03-13) Cortés Giraldo, Miguel Antonio; Carabe, A.; Física Atómica, Molecular y Nuclear
We compare unrestricted dose average linear energy transfer (LET) maps calculated with three different Monte Carlo scoring methods in voxelized geometries irradiated with proton therapy beams with three different Monte Carlo scoring methods. Simulations were done with the Geant4 (Geometry ANd Tracking) toolkit. The first method corresponds to a step-by-step computation of LET which has been reported previously in the literature. We found that this scoring strategy is influenced by spurious high LET components, which relative contribution in the dose average LET calculations significantly increases as the voxel size becomes smaller. Dose average LET values calculated for primary protons in water with voxel size of 0.2 mm were a factor ~1.8 higher than those obtained with a size of 2.0 mm at the plateau region for a 160 MeV beam. Such high LET components are a consequence of proton steps in which the condensed-history algorithm determines an energy transfer to an electron of the material close to the maximum value, while the step length remains limited due to voxel boundary crossing. Two alternative methods were derived to overcome this problem. The second scores LET along the entire path described by each proton within the voxel. The third followed the same approach of the first method, but the LET was evaluated at each step from stopping power tables according to the proton kinetic energy value. We carried out microdosimetry calculations with the aim of deriving reference dose average LET values from microdosimetric quantities. Significant differences between the methods were reported either with pristine or spread-out Bragg peaks (SOBPs). The first method reported values systematically higher than the other two at depths proximal to SOBP by about 15% for a 5.9 cm wide SOBP and about 30% for a 11.0 cm one. At distal SOBP, the second method gave values about 15% lower than the others. Overall, we found that the third method gave the most consistent performance since it returned stable dose average LET values against simulation parameter changes and gave the best agreement with dose average LET estimations from microdosimetry calculations.
An implementation to read and write IAEA phase-space files in GEANT4-based simulations
(Taylor & Francis, 2012) Cortés Giraldo, Miguel Antonio; Quesada Molina, José Manuel; Gallardo Fuentes, María Isabel; Capote, Roberto; Física Atómica, Molecular y Nuclear
Purpose: To develop a stand-alone code to make any application coded with the GEANT4 (GEometry ANd Tracking, version 4) toolkit capable of reading and writing phase-space (phsp) files in the format created by the IAEA (International Atomic Energy Agency), so that the exchange of phsp files between other validated Monte Carlo (MC) codes and GEANT4 is possible. Methods: We present a stand-alone code, written in C++ object-oriented language, developed in a way that ensures the compatibility with future versions of the IAEA phsp format. The aim of the reader part is to get the information from a given IAEA phsp file and create the primary particles in a GEANT4 user application. On the other hand, the writer part of the code is the responsible for writing the IAEA phsp files during a run of the GEANT4 application. Results: A testing simulation was written with GEANT4 to verify the performance of this code, with satisfactory results. An example of use in a GEANT4 application which simulates the treatment head of a radiotherapy linear electron accelerator (linac) is also shown, comparing dose calculations with experimental data. Conclusions: This stand-alone package, which can be used in any GEANT4 application, allows the exchange of validated phsp files between different MC codes and the use of phsp data from many different accelerators and fields in dosimetry studies. Furthermore, it also offers additional utilities of interest in medical applications.
Implementation of the microdosimetric kinetic model using analytical microdosimetry in a treatment planning system for proton therapy
(Elsevier, 2021) Bertolet, A.; Cortés Giraldo, Miguel Antonio; Carabe-Fernández, A.; Física Atómica, Molecular y Nuclear; Gobierno de España
Purpose To implement RBE calculations in treatment planning systems based on the Microdosimetric Kinetic Model (MKM) upon analytical calculations of dose-mean lineal energy (𝑦𝐷). MKM relies on the patterns of energy deposition in sub-nuclear structures called domains, whose radii are cell-specific and need to be determined. Methods and material The radius of a domain (𝑟𝑑) can be determined from the linear-quadratic (LQ) curves from clonogenic experiments for different cell lines exposed to X-ray and proton beams with known 𝑦𝐷. In this work, LQ parameters for two different human lung cell lines (H1299 and H460) are used, and 𝑦𝐷 among cells is calculated through an analytical algorithm. Once 𝑟𝑑 is determined, MKM-based calculations of RBE are implemented in a treatment planning system (TPS). Results are compared to those produced by phenomenological models of RBE, such as Carabe and McNamara. Results Differences between model-based predictions and experimentally determined RBE are analyzed for 𝑦𝐷=5 keV/μm. For the H1299 line, mean differences in RBE are 0.13, −0.29 and −0.27 for our MKM-based calculation, Carabe and McNamara models, respectively. For the H460 line, differences become −0.044, −0.091 and −0.048, respectively. RBE is computed for these models in a simple plan, showing MKM the best agreement with the experimentally obtained RBE, keeping deviations below 0.08. Conclusions Microdosimetry calculations at the TPS-level provide tools to improve predictions of RBE using the MKM with actual values of 𝑦𝐷 instead of LET. The radius of the characteristic domain needs to be determined to tailor the RBE prediction for each cell or tissue.
Characterisation of the neutron beam in the n_TOF-EAR2 experimental area at CERN following the spallation target upgrade
(Springer, 2025-12-08) Pavon-Rodríguez, J.A.; Lerendegui Marco, Jorge; Manna, A.; Amaducci, S.; Sabaté-Gilarte, M.; Musacchio-Gonzalez, E.; Bacak, M.; Alcayne, V.; Cortés Giraldo, Miguel Antonio; Vlachoudis, V.; Zarrella, R.; García-Infantes, F.; Casanovas, A.; Stamati, M.E.; Patronis, N.; Tassan-Got, L.; Quesada Molina, José Manuel; The n_TOF Collaboration; Pérez Maroto, Pablo; Física Atómica, Molecular y Nuclear; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; Agencia Estatal de Investigación. España
The n_TOF facility at CERN has undergone a major upgrade after the installation of a new spallation target, designed to improve the performance of both neutron beamlines at the experimental areas 1 and 2 (EAR1 and EAR2) and the commissioning of a new experimental area (NEAR). Due to improved coupling of the spallation target with the EAR2 beamline, the upgrade resulted in a significantly increased neutron flux and improved neutron energy resolution. This paper presents the results of the commissioning phase that followed to characterise the EAR2 neutron beamline and validate the FLUKA Monte Carlo simulations of the facility. The main characteristics of the neutron beam, namely the neutron flux, spatial profile and energy resolution, are evaluated and compared to the previous target. The neutron flux presents a general increase of 20% below 1 eV, 40% between 1 eV and 100 keV and 50% between 100 keV and 10 MeV. The measured width of the beam profile was 3 cm full width at half maximum (FWHM) at the reference position for neutron capture measurements. The energy resolution with the new spallation target shows a significant improvement compared to the previous one. Moreover, FLUKA Monte Carlo simulations present a good agreement with the measured neutron flux and profile within uncertainties, and a remarkable reproduction of the energy resolution.
New data for the definition of neutron beams for Boron Neutron capture therapy
(Elsevier, 2021-08) Macías Martínez, Miguel; Fernández Martínez, Begoña; Praena, J.; Física Atómica, Molecular y Nuclear; Ministerio de Economía y Competitividad (MINECO). España; Junta de Andalucía; Asociación Española contra el Cárcer (AECC)
Boron Neutron Capture Therapy (BNCT) is neutron radiotherapy used to treat tumours cells previously doped with Boron-10. This therapy requires an epithermal neutron beam for the treatment of deep tumours and a thermal beam for shallow ones. Thanks to recent high-current commercial accelerators, Accelerator-Based Neutron Sources (ABNS) are a competitive option for providing therapeutic neutron beams in hospitals. In this work, the neutron field generated by the 7Li (p,n)7Be reaction at 1950 keV is studied as a neutron source in ABNS, being measured by the Time-Of-Flight (TOF) technique at HiSPANoS facility (Spain). Moreover, two Beam Shaping Assemblies (BSA) for deep and shallow tumour treatment, which are specially designed for the 1950 keV neutron field, are evaluated for BNCT via Monte Carlo simulations (MCNP). Results in agreement with the International Atomic Energy Agency (IAEA) figures of merit endorse the use of this neutron field for BNCT.
The first neutron time-of-flight line in Spain: Commissioning and new data for the definition of a neutron standard field
(Elsevier, 2020-03) Macías Martínez, Miguel; Fernández Martínez, Begoña; Praena, Javier; Física Atómica, Molecular y Nuclear; Ministerio de Economía y Competitividad (MINECO). España; Asociación Española contra el Cáncer (AECC); Junta de Andalucía
The National Accelerator Laboratory (CNA) has developed the first accelerator line in Spain devoted to the measurement of cross sections involving neutrons by means of the time-of-flight technique. For neutron generation, pulsed proton beams with 1 nsec pulse width and with variable repetition rates are delivered. The data acquisition has been built using a CAEN Digitizer. The aim of this work is to demonstrate the good performance of the time-of-flight system. The commissioning of the line has consisted of the measurement of the neutron field generated by protons at 1912 keV impinging on a thick lithium target. Such a field has been extensively used in nuclear astrophysics since 1988. Recently, there have been experimental works with the goal to support it as a standard neutron field. The results show the good performance of the time-of-flight system and also support its possible definition as a standard.
Soft error rate comparison of 6T and 8T SRAM ICs using mono-energetic proton and neutron irradiation sources
(Elsevier, 2017-11) Malagón, D.; Bota, S. A.; Torrens, G.; Praena, J.; Fernández Martínez, Begoña; Macías Martínez, Miguel; Quesada Molina, José Manuel; Guerrero Sánchez, Carlos; Jiménez Ramos, María del Carmen; García López, Francisco Javier; Merino, J. L.; Segura, J.; Física Atómica, Molecular y Nuclear; Física Aplicada II; Ministerio de Economía y Competitividad (MINECO). España
We present experimental results of soft errors produced by proton and neutron irradiation of minimum-size six-transistors (6T) and eight-transistors (8T) bit-cells SRAM memories produced with 65 nm CMOS technology using an 18 MeV proton beam and a neutron beam of 4.3–8.5 MeV. All experiments have been carried out at the National Center of Accelerators (CNA) in Seville, Spain. Similar soft error rate levels have been observed for both cell designs despite the larger area occupied by the 8T cells, although the trend for multiple events has been higher in 6T.
Trace americium contamination sources in the environment can be detected using 243Am/241Am
(Springer Nature, 2026) Chamizo, Elena; López Lora, Mercedes; López Fuentes, Antonio Jesús; Física Atómica, Molecular y Nuclear; Física Aplicada II; Centro Nacional de Aceleradores (CNA); Ministerio de Ciencia, Innovación y Universidades (MICIU). España; Agencia Estatal de Investigación. España
Despite the widespread presence of americium in the environment since the 1950s from nuclear activities, the use of americium isotopic composition to trace contamination sources has not been investigated. Here we report the detection of 243 Am in environmental samples and demonstrate that the ratio of 243 Am to 241 Am can serve as a distinctive fingerprint of radioactive emissions, with characteristic values of 0.05 for thermonuclear explosions, 0.023 for global fallout, below 0.0015 for low-yield nuclear tests, and 0.0013 for releases from a nuclear reprocessing facility. In nuclear detonations, 243 Am is produced as the decay product of 243 Pu. The ratio of 243 Am to 239 Pu in global fallout is about 3.2 × 10⁻⁴, supporting the predicted formation of neutron-rich heavy plutonium isotopes during nuclear detonations.
Feasibility of a new GRT setup for the analysis of quaternary metal alloys with radioactive gamma sources
(Elsevier, 2025-11) Moreno-Soto, Javier; Ager Vázquez, Francisco José; Paúl Escolano, Antonio; Gómez Tubío, Blanca; Ortega-Feliú, Inés; Ferreti, Marco; Respaldiza Galisteo, Miguel Ángel; Física Aplicada I; Ingeniería y Ciencia de los Materiales y del Transporte; Física Aplicada III; Física Atómica, Molecular y Nuclear; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; European Union (UE); RNM138: Física Nuclear Aplicada; TEP973: Tecnología de Polvos y Corrosión
Analysing archaeological artefacts made from metallic alloys is often challenging due to the impracticality of sample collection. Traditional non-invasive surface techniques, such as X-ray fluorescence (XRF), electron probe microanalysis (EPMA), scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX), and particle-induced X-ray emission (PIXE), among others, may yield misleading results if the objects are affected by corrosion or enrichment effects. Consequently, these techniques need to be complemented with others to gain a precise understanding of alloy composition. Gamma-ray transmission (GRT) is a non-destructive technique that can reveal the bulk composition of a sample. A new GRT setup has been developed to measure the concentrations of binary, ternary, and quaternary alloys using three sources simultaneously, reducing the measurement time. Alloys made in the laboratory were analysed with XRF, showing notable composition discrepancies in some cases, while the GRT results agreed with the expected composition. This innovative GRT setup, with its potential to significantly contribute to future archaeological investigations of alloy compositions, proves to be a valuable tool for analysing metallic artefacts.
Calibration and Performance Tests of Detectors for Laser-Accelerated Protons
(Institute of Electrical and Electronics Engineers (IEEE), 2015-11-09) Seimetz, M.; Bellido, P.; Soriano, A.; García López, Francisco Javier; Jiménez Ramos, María del Carmen; Fernández Martínez, Begoña; Conde, P.; Crespo, E.; González, A. J.; Benlloch, J. M.; Física Atómica, Molecular y Nuclear; Física Aplicada II; Ministerio de Economía y Competitividad (MINECO). España; Agencia Estatal de Investigación. España; Generalitat Valenciana
We present the calibration and performance tests carried out with two detectors for intense proton pulses accelerated by lasers. Most of the procedures were realized with proton beams of 0.46-5.60 MeV from a tandem accelerator. One approach made use of radiochromic films, for which we calibrated the relation between optical density and energy deposition over more than three orders of magnitude. The validity of these results and of our analysis algorithms has been confirmed by controlled irradiation of film stacks and reconstruction of the total beam charge for strongly non-uniform beam profiles. For the spectral analysis of protons from repeated laser shots, we have designed an online monitor based on a plastic scintillator. The resulting signal from a photomultiplier directly measured on a fast oscilloscope is especially useful for time-of-flight applications. Variable optical filters allow for suppression of saturation and an extension of the dynamic range. With pulsed proton beams we have tested the detector response to a wide range of beam intensities from single particles to 3 ×105 protons per 100 ns time interval.
Nanosecond pulsed proton beam: Upgrade of the accelerator-based neutron facility HiSPANOS at CNA (Spain)
(Società Italiana di Fisica, 2019-07-01) Macias Martínez, Miguel; Fernández Martínez, Begoña; Labrador, Juan A.; Romero, A.; Praena, Javier; Física Atómica, Molecular y Nuclear; Ministerio de Economía y Competitividad (MINECO). España; Junta de Andalucía; Asociación Española Contra el Cáncer
The 3 MV Tandem Pelletron accelerator at the Spanish Accelerator Laboratory (CNA) has been recently upgraded to produce pulsed ion beams for neutron Time-Of-Flight (TOF) measurements. The upgrade has consisted of two actions: a pulsing system installed at the low energy part of the Tandem accelerator and a new line fully equipped. The pulsing system provides approximately one nanosecond pulse width of protons with variable repetition rates from kHz down to MHz. The new line is equipped with conventional devices and a pick-up for timing measurements with high resolution. The properties of the whole system have been tested under various working conditions and they are described in some detail.
Time-optimal synchronization to self-sustained oscillations under bounded control
(APS, 2025-11-19) Ríos Monje, Carlos; Plata Ramos, Carlos Alberto; Guéry-Odelin, D.; Prados Montaño, Antonio; Física Atómica, Molecular y Nuclear; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; Agencia Estatal de Investigación. España
Incorporating force bounds is crucial for realistic control implementations in physical systems. Here, we investigate the fastest possible synchronization of a Liénard system to its limit cycle using a bounded external force. To tackle this challenging nonlinear optimal control problem, our approach involves applying Pontryagin’s maximum principle with a combination of analytical and numerical tools. We show that the optimal control develops a remarkably complex structure in phase space as the force bound is lowered. Trajectories rewound from the limit cycle’s extreme points turn out to play a key role in determining the maximum number of control bangs for optimal connection. We illustrate these intricate features using the paradigmatic van der Pol oscillator model.
The ANC of 16O states from 7Be+12C α-transfer reaction to study 12C(α,γ)16O
(Elsevier, 2025-08) Kundalia, Kabita; Gupta, D.; Ali, S.M.; Mitra, R.; Saha, S.K.; Tengblad, O.; Perea, A.; Martel, I.; Cederkall, J.; Moro Muñoz, Antonio Matías; Física Atómica, Molecular y Nuclear; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; Agencia Estatal de Investigación. España
We measured the angular distributions for theC(Be,He)O transfer reaction at 35 MeV leading to several excited states ofO. The angular distribution of the ground state ofO was measured for the first time in this reaction. The corresponding Asymptotic Normalization Coefficients (ANC) of all the observed states were determined. The ANC of ground state, 6.92 MeV (2) and 7.12 MeV (1) subthreshold states ofO obtained from this work are utilized to determine the astrophysical 1 and 2 -factors of theC(O reaction in an -matrix analysis.
First simultaneous observation of co- and counter-current fast-ion losses in the ASDEX Upgrade tokamak
(IOP Publishing LTD, 2025-09-25) Reyner-Viñolas, A.; Hidalgo-Salaverri, J.; Galdón Quiroga, Joaquín; Rueda Rueda, José; González Martín, Javier; Ordóñez-Jiménez, J. M.; García Muñoz, Manuel; EUROfusion Tokamak Exploitation Team; Física Atómica, Molecular y Nuclear; Ingeniería Mecánica y Fabricación; EUROfusion Consortium
In ITER and future fusion power plants, the source of the fusion born alpha particles is almost isotropic in pitch angle, thus having co- and counter-current populations. For trapped ions, the co-current side of the orbit corresponds to its outer leg, while the counter-current side corresponds to the inner leg. Understanding the mechanisms responsible for the fast-ion losses (FILs) is critical for future magnetically confined fusion power plants. To further study the interplay of fast ions with plasma instabilities, a double pinhole collimator has been developed for a Fast-Ion Loss Detector (FILD) in the ASDEX Upgrade tokamak (AUG). This new FILD opens the operational window to simultaneous measurements of the co- and counter-current ion velocity-space. In this paper, the first results for the AUG double collimator FILD detector are shown. The commissioning of this new probe is carried out in H-mode plasmas with an on-axis magnetic field T, and a plasma current MA. Simultaneous co- and counter-current FILs have been measured. Both have shown a similar dependence on Ion Cyclotron Resonance Heating (ICRH) power, where the main difference is the intensity of the losses, with the co-losses being an order of magnitude larger. Toroidal Alfvén eigenmode-coherent ICRH-only losses have been identified for the co-current ions. Additionally, the presence of Edge Localized Modes during the discharge were shown to increment Neutral Beam Injection prompt losses, while partially mitigating ICRH-driven losses on both co- and counter- sides of the velocity-space. Finally, a very trapped and high gyroradius losses, with an unclear origin, have been measured in the co- and counter-current velocity-space. The computed ion trajectories show that these ions remain permanently near the vessel wall, suggesting that they are accelerated within the scrape-off layer.
First Differential Measurement of the Single π^{+} Production Cross Section in Neutrino Neutral-Current Scattering
(American Physical Society, 2025-10-23) Abe, K.; Abe, S.; Akutsu, R.; Alarakia-Charles, H.; Alj Hakim, Y. I.; Alonso Monsalve, S.; Anthony, L.; Caballero Carretero, Juan Antonio; González Jiménez, Raúl; González Rosa, Jesús; T2K Collaboration; Física Atómica, Molecular y Nuclear; Deutsche Forschungsgemeinschaft (DFG); National Research, Development and Innovation Office. Hungary; National Science Centre. Poland; Ministry of Science and Higher Education, Russia; NAFOSTED, Vietnam; VAST-JSPS
Since its first observation in the 1970s, neutrino-induced neutral-current single positive pion production (NC⁢1⁢𝜋+) has remained an elusive and poorly understood interaction channel. This process is a significant background in neutrino oscillation experiments and studying it further is critical for the physics program of next-generation accelerator-based neutrino oscillation experiments. In this Letter, we present the first double-differential cross-section measurement of NC⁢1⁢𝜋+ interactions using data from the ND280 detector of the T2K experiment collected in 𝜈-beam mode. The measured flux-averaged integrated cross section is 𝜎=(6.07±1.22)×10−41 cm2/nucleon. We compare the results on a hydrocarbon target to the predictions of several neutrino interaction generators and final-state-interaction models. While model predictions agree with the differential results, the data show a weak preference for a cross-section normalization approximately 30% higher than predicted by most models studied in this Letter.
Status of the NUMEN Construction
(EDP Sciences, 2025-08) Pierroutsakou, D.; Acosta, L.; Added, N.; Agodi, C.; Aguiar, V.A.P; Amador-Valenzuela, P.; Lay Valera, José Antonio; Yildirim, A.; Física Atómica, Molecular y Nuclear
The NUMEN (NUclear Matrix Elements for Neutrinoless double beta decay) project at INFN-Laboratori Nazionali del Sud aims to extract quantitative information on the Nuclear Matrix Elements relevant to neutrinoless double beta decay, a key process for determining whether the neutrino is a Majorana or Dirac particle and for establishing its effective mass. This objective will be pursued by measuring the cross sections of double charge exchange reactions induced by intense heavy-ion beams on selected isotopes that are candidates for neutrinoless double beta decay. The need to measure extremely low cross sections with high statistical significance has driven a major upgrade of the entire INFN-LNS infrastructure, enabling the production of heavy-ion beams with intensities up to 1013 pps at the position of the experimental target. Additionally, significant enhancements are being made to the focal plane detectors of the existing MAGNEX spectrometer. A new target system and advanced detectors are under development to track and identify heavy ions at an expected rate of 5×106 Hz at full beam intensity, while also allowing γ-ray detection. This contribution provides an overview of the current status of the NUMEN project, highlighting recent developments and characterization campaigns for nuclear targets and detector systems.
Porous Cu thin films prepared by magnetron sputtering using helium as depositing gas
(Elsevier, 2025-10-23) Arzac Di Tomaso, Gisela Mariana; López Viejobueno, Jennifer; Calvo, Mauricio E.; Ferrer Fernández, Francisco Javier; Fortio Godinho, Vanda Cristina; Hufschmidt, Dirk; Jiménez de Haro, María del Carmen; Ramírez Rico, Joaquín; Varela, Francisco; Fernández, Asunción; Física Atómica, Molecular y Nuclear; Física de la Materia Condensada; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España
In this work, porous copper thin films were prepared by magnetron sputtering (MS) deposition using helium as the process gas. Electron microscopy techniques were used to study the shape, size, amount and distribution of the pores. Working under direct current (DC) or radiofrequency (RF) conditions, enabled to achieve respectively a dense porous or an open porous columnar microstructure. At the nanoscopic level a characteristic solid-gas nanocomposite structure was also produced in both films. Spherical and faceted nano-bubbles filled with helium, with a size range of 1–22 nm and a uniform distribution across the entire thickness were visualized. RF conditions allowed higher gas loading, achieving up to 6.2 at.% He preferentially occluded in smaller pores. Characterization revealed that the RF-deposited copper (Cu) film is oxidised to a greater depth than the DCdeposited film, forming a thicker copper oxide(s) layer. This phenomenon can be attributed to the open porous nanostructure of the former. The results presented herein improve our understanding of MS deposition of copper with helium as process gas and pave the way for designing a wide range of materials with applications in the field of fusion reactors, (electro)catalysis, photocatalysis, fuel cells, electronics and the fabrication of negative crystals.

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