Publications

2022 | 2021 | 2020 | 2019

Below, by year, are the publications listed in the HAL open archive.

2025

Polarization Ratios of Turbulent Langmuir/$\mathcal{Z}$ -mode Waves Generated by Electron Beams in Magnetized Solar Wind Plasmas
- Polanco-Rodríguez F J
- Krafft C.
- Savoini P.
The Astrophysical Journal Letters, Bristol : IOP Publishing, 2025, 989 (2), pp.L38. The polarization ratios F = ∣E<sub>⊥</sub>∣<sup>2</sup>/∣E∣<sup>2</sup> of beam-generated turbulent Langmuir/Z-mode ($\mathcal{LZ}$) waves and electromagnetic emissions radiated at plasma frequency ω<sub>p</sub> from such sources are studied in weakly magnetized and randomly inhomogeneous plasmas. Large-scale and long-term 2D/3V particle-in-cell simulations with parameters relevant to type III solar radio bursts are performed. Statistical studies using waveforms recorded by virtual satellites are carried out to determine the distributions of polarization ratios as a function of beam and plasma parameters. This efficient method, which mimics waveform recording by spacecraft in the solar wind, leads to results consistent with observations. Moreover, plasma random density fluctuations δn turn out to be the key factor responsible for the increase in polarization ratios up to F ∼ 1. Indeed, it is demonstrated that linear mode conversion at constant frequency near of ω<sub>p</sub> of $\mathcal{LZ}$ waves scattering on δn is the most efficient and fastest process to produce large polarization ratios in randomly inhomogeneous plasmas. This is due to electromagnetic slow extraordinary $\mathcal{Z}$-mode wave emission by $\mathcal{LZ}$ wave turbulence. The results provide guidance to theoretical studies and useful support to estimate the average level of density fluctuations in solar wind plasmas. (10.3847/2041-8213/adf4ce)
DOI : 10.3847/2041-8213/adf4ce
A Gyromoment Approach for Electron Dynamics in Low-Temperature E × B Plasmas of Hall Thrusters
- Tazakkati Zoubaïr
- Laguna Alejandro Alvarez
- Massot Josselin
- Massot Marc
- Pichard Teddy
, 2025. <div><p>We study the electron dynamics in the acceleration region of a Hall thruster (HT). The strong crossed electric and magnetic fields induce both a fast electron cyclotron gyration around the magnetic field lines and a E × B drift. Starting from a Boltzmann-Poisson system, we perform a dimensional analysis to identify the dominant physical effects within this zone. This yields a non-dimensional kinetic equation tailored to the regime of interest, featuring multiple small parameters and a clear scale separation. The fast cyclotron gyration are filtered out through a Hilbert expansion combined with a gyroaveraging operator, yielding a reduced gyrokinetic model. Then a gyrofluid model is derived using a moment method with an entropy-based closure. Owing to the symmetries introduced by the gyroaveraging process, the number of required moments is reduced, and the closure corresponds to an anisotropic Gaussian requiring only four moments: the density, parallel momentum, and two directional temperatures. A numerical strategy using common tools from the literature is provided to handle the remaining small scales. Numerical experiments exhibit promising results for our applications.</p></div>
Generation of zonal flows and impact on transport in competing drift waves and interchange turbulence
- Panico Olivier
- Sarazin Yanick
- Hennequin Pascale
- Gürcan Ozgur
- Dif-Pradalier Guilhe
- Garbet Xavier
- Varennes Robin
Journal of Plasma Physics, Cambridge University Press (CUP), 2025, 91 (4), pp.E118. The generation and radial structure of zonal flows are studied in competing collisional drift waves and interchange turbulence using the reduced flux-driven nonlinear model Tokam1D. Zonal flows are generated in both the interchange dominated and adiabatic regimes with the former favoring radially structured flows and avalanche transport. The distance to the instability threshold proves to be key, with a more stable radial flow structure emerging near the threshold and increased energy stored in the flows for interchange turbulence. The avalanches are shown to perturb zonal flow structures in drift-wave turbulence and to reactivate them in the interchange regime. Finally, the ExB staircases with radially structured, stable in time zonal flows are proved beneficial for the overall confinement. (10.1017/s0022377825100603)
DOI : 10.1017/s0022377825100603
Photoelectric Effect in Air Explains Lightning Initiation and Terrestrial Gamma Ray Flashes
- Pasko Victor P
- Celestin Sebastien
- Bourdon Anne
- Janalizadeh Reza
- Pervez Zaid
- Jansky Jaroslav
- Gourbin Pierre
Journal of Geophysical Research: Atmospheres, American Geophysical Union, 2025, 130 (14). Terrestrial gamma ray flashes (TGFs) are high‐energy photon bursts that have been linked to short bursts of electromagnetic radiation associated with lightning activity. The most puzzling unexplained aspect of these events is that gamma rays originate from very compact regions of space while the source regions often seem to be optically dim and radio silent when compared to processes in ordinary lightning discharges. In this work, we report a mechanism that allows precise quantitative explanation of these peculiar features of TGFs and their relationships to the observed waveform characteristics of associated radio emissions. The mechanism represents an extension of earlier ideas on feedback processes in growth of relativistic runaway electron avalanches (Dwyer, 2003, https://doi.org/10.1029/2003GL017781 ), and is based on a recent demonstration of the dominant role of the photoelectric feedback on compact spatial scales (Pasko, Celestin, et al., 2023, https://doi.org/10.1029/2022GL102710 ). Since discussed events often occur in isolation or precede formation of lightning discharges, the reported findings propose a straightforward solution for the long‐standing problem of lightning initiation. (10.1029/2025JD043897)
DOI : 10.1029/2025JD043897
Comparative Study on Microwave Diagnostics: Cutoff Probe, Hairpin Probe, and Microwave Interferometer
- Kim S.
- Booth Jean-Paul
- Curley Garrett
, 2025. We have compared three microwave diagnostic techniques for electron density measurement in a 13.56MHz ICP reactor in pure Ar: the cutoff probe, hairpin probe, and a microwave interferometer. The interferometer showed the highest density, followed by the hairpin and cutoff probes, indicating that the probe antenna surface acts as a loss channel for charged particles, leading to a reduction in electron density. Furthermore, we found that the perturbation is localized near the probe.
In-situ measurement of surface reaction probabilities in low-pressure plasmas
- Booth Jean-Paul
- Zhang Shu
- Curley Garrett
, 2025. Surface-catalysed recombination is often the dominant loss process for reactive atoms and free radicals created in low-pressure plasmas in molecular gases. However, ab-initio theoretical methods to estimate the rates of these processes are far from mature, in part due to the complexity of the chemical composition and morphology of surfaces subjected to energetic ion bombardment. Therefore, reliable in-situ measurements are essential to understand the chemical kinetics of these systems. A number of experimental techniques to measure surface reaction rates have been developed, and will be reviewed in this talk. However, analysis of these experimental results has historically relied on simplifying assumptions, notably that of constant surface reaction probability, . However, high-quality data from improved experimental techniques combined with systematic measurements in simplified model systems has shown that this assumption is far from correct in many circumstances. More sophisticated surface models are therefore necessary.
Towards calibration of picosecond O-TALIF
- Shu Z
- Latorre Sopie
- Billeau J.B.
- Booth Jean-Paul
- Seletskiy D.V.
- Reuter Stefan
- Popov N.A.
- Starikovskaia Svetlana
, 2025. Experimental procedure of obtaining the Xe/O two-photon absorption cross-section ratio is discussed for nanosecond and picosecond TALIF experiments. The same nanosecond capillary discharge with 100% oxygen dissociation at 30 mbar pressure is used as a source of O-atoms.
Modeling of N2-H2 DC discharges for ammonia production
- Alves Luis Lemos
- Pereira P
- Baghel S.S.
- Goncalves A.
- Budde Maik
- Booth Jean-Paul
- Guaitella Olivier
- Pinhão N.
- Pintassilgo C D
- Marques L.
, 2025. In this work we present the on-going validation of a kinetic model for nitrogen-hydrogen plasmas, highlighting the significance of plasma-surface interactions in ammonia production.
BepiColombo cruise science: overview of the mission contribution to heliophysics
- Sánchez-Cano Beatriz
- Hadid Lina Z
- Aizawa Sae
- Murakami Go
- Bamba Yumi
- Chiba Shota
- Hara Takuya
- Heyner Daniel
- Ho George
- Iwai Kazumasa
- Kilpua Emilia
- Kinoshita Gaku
- Lavraud Benoit
- Miyoshi Yoshizumi
- Pinto Marco
- Schmid Daniel
- Shiota Daikou
- Vainio Rami
- Andre Nicolas
- Aronica Alessandro
- Asmar Sami
- Auster Hans-Ulrich
- Barabash Stas
- Barthe Alain
- Baumjohann Wolfgang
- Benkhoff Johannes
- Bentley Mark
- Bunce Emma
- Cappuccio Paolo
- Delcourt Dominique
- Di Stefano Ivan
- Doria Irene
- Dresing Nina
- Fedorov Andrei
- Fischer David
- Fiethe Bjorn
- Fränz Markus
- Gieseler Jan
- Giner Franz
- Giono Gabriel
- Harada Yuki
- Hussmann Hauke
- Iess Luciano
- Imamura Takeshi
- Jeszenszky Harald
- Jones Geraint
- Katra Bruno
- Kazakov Adrian
- Kozyrev Alexander
- Laky Gunter
- Lefevre Carlo
- Lichtenegger Herbert
- Lindsay Simon
- Lucente Marco
- Magnafico Carmelo
- Magnes Werner
- Martindale Adrian
- Matsuoka Ayako
- Milillo Anna
- Mitrofanov Igor
- Nishiyama Gaku
- Oleynik Philipp
- Orsini Stefano
- Paik Meegyeong
- Palmroos Christian
- Plainaki Christina
- Penou Emanuel
- Persson Moa
- Quarati Francesco
- Quémerais Eric
- Richter Ingo
- Robidel Rozenn
- Rojo Mathias
- Saito Yoshifumi
- Santoli Francesco
- Stark Alexander
- Stumpo Mirko
- Tian Rong
- Varsani Ali
- Verdeil Christopher
- Williamson Hayley
- Witasse Olivier
- Yokota Shoichiro
Earth Planets and Space, Springer / Terra Scientific Publishing Company, 2025, 77, pp.114. BepiColombo, the joint ESA/JAXA mission to Mercury, was launched in October 2018 and is scheduled to arrive at Mercury in November 2026 after an 8-year cruise. Like other planetary missions, its scientific objectives focus mostly on the nominal, orbiting phase of the mission. However, due to the long duration of the cruise phase covering distances between 1.2 and 0.3 AU, the BepiColombo mission has been able to outstandingly contribute to characterise the solar wind and transient events encountered by the spacecraft, as well as planetary environments during the flybys of Earth, Venus, and Mercury, and contribute to the characterisation of the space radiation environment in the inner Solar System and its evolution with solar activity. In this paper, we provide an overview of the cruise observations of BepiColombo, highlighting the most relevant science cases, with the aim of demonstrating the importance of planetary missions to perform cruise observations, to contribute to a broader understanding of Space Weather in the Solar System, and in turn, increase the scientific return of the mission. (10.1186/s40623-025-02256-z)
DOI : 10.1186/s40623-025-02256-z
Plasma Pressure Response to Non-Inductive Current Drive in Axisymmetric Viscoresistive MHD Steady-states
- Krupka Anna
- Firpo Marie-Christine
Journal of Plasma Physics, Cambridge University Press (CUP), 2025, 91 (4), pp.E126. <div><p>We investigate self-consistent, steady-state axisymmetric solutions of incompressible tokamak plasma using a visco-resistive magnetohydrodynamic model. A key contribution of this work is the formulation of Poisson's equation that governs the pressure profile. Our analysis reveals that the current modeling fails to produce realistic pressure levels. To overcome this limitation, we introduce additional non-inductive current drives, akin to those generated by neutral beam injection or radio frequency heating, modeled as modifications to the toroidal current. Numerical simulations validate our enhanced model, showing significant improvements in pressure profile characteristics. In the cases examined, the effect of these current drives on the velocity profiles is moderate, except when the non-inductive current drives induce reversals in the total toroidal current density, leading to non-nested flux surfaces with internal separatrices.</p></div> (10.1017/S0022377825100743)
DOI : 10.1017/S0022377825100743
Pre-flight performance of the ion energy mass spectrum analyzer for the Martian Moons eXploration (MMX) mission
- Yokota Shoichiro
- Matsuoka Ayako
- Murata Naofumi
- Saito Yoshifumi
- Asamura Kazushi
- Kasahara Satoshi
- Delcourt Dominique
- Hadid Lina Z
- Terada Naoki
- Keika Kunihiro
- Harada Yuki
- Nakagawa Hiromu
- Masunaga Kei
- Sakai Shotaro
- Futaana Yoshifumi
- Imajo Shun
- Seki Kanako
- Nishino Masaki N
- Kitamura Yuki
Progress in Earth and Planetary Science, Springer/Japan Geoscience Union, 2025, 12 (1), pp.51. Abstract An ion energy mass spectrum analyzer was developed for the Martian Moons eXploration (MMX) mission to measure the three-dimensional velocity distribution function and mass profile of low-energy ions around the Mars-Moon system. The hemispheric field-of-view (FOV) is acquired by a pair of angular scanning deflectors, and the energy/charge and mass/charge are determined for each ion by an electrostatic analyzer and a linear-electric-field (LEF) time-of-flight (TOF) analyzer, respectively, with an enhanced mass resolution of $$m/\Delta m\sim 100$$ m / Δ m ∼ 100 . The ion analyzer, together with magnetometers, constitutes the mass spectrum analyzer (MSA), one of the scientific instruments on board the MMX spacecraft. This paper describes the instrumentation of the ion analyzer, and results of the performance tests of its flight model (FM). (10.1186/s40645-025-00718-2)
DOI : 10.1186/s40645-025-00718-2
Statistical properties of beam-driven upper-hybrid wave turbulence in the solar wind
- Annenkov V.
- Krafft C.
- Volokitin A.
- Savoini P.
Astronomy & Astrophysics - A&A, EDP Sciences, 2025, 699, pp.L6. We studied the statistical properties of beam-driven upper-hybrid wave turbulence in the solar wind by focusing on the probability density functions (PDFs) of electric field amplitudes, |E|. We used, for the first time, high-resolution and long-term 2D particle-in-cell simulations of the interaction of an electron beam with a magnetized plasma to calculate and analyse the skewness (degree of anisotropy) and the kurtosis (degree of flatness) of the PDFs of |E| and log|E|2 for various intensities of plasma magnetization (Ω = ωc/ωp) and average levels of random density fluctuations (ΔN). Using the Pearson classification, we show that the PDFs of log|E|2 predominantly align with Type VI Pearson distributions, with a shift towards Type I at high plasma magnetizations. In contrast, the PDFs of |E| are Type I Pearson distributions regardless of the Ω and ΔN values. Comparisons between simulation results and observations by the Solar Orbiter’s Time Domain Sampler instrument show a good agreement. This study also offers a promising method for understanding the dynamics of wave turbulence and indirectly estimating plasma magnetization. (10.1051/0004-6361/202555087)
DOI : 10.1051/0004-6361/202555087
Cold plasma treatment of cholangiocarcinoma: investigating skin tissue as a barrier to electric field propagation and reactive species diffusion
- Biaffeu Nematchoua Emérick Maurian
- Manon Soulier
- Dufour Thierry
- Fouassier Laura
- Janona Marion
, 2025.
Optimizing a cold plasma catheter for the local treatment of biliary tract cancer
- Soulier Manon
- Géraud Korentin
- Fouassier Laura
- Camus Marine
- Dufour Thierry
, 2025. This work consists in developing a cold atmospheric plasma (CAP) catheter designed to fit an endoscope and to demonstrate its safety to elicit local antitumor effects in cholangiocarcinoma, a cancer of the biliary tract. Such device relies on very constraining specifications to ensure electrical and thermal safety, both for patients and practitioners. In preclinical models mimicking human biliary tract, we demonstrate that our plasma catheter can safely operate in a confined environment (Ømax = 6 mm) in presence of a conductive liquid flow (bile). Exposure of a bile substitute to CAP leads to an increase in nitrite and hydrogen peroxide species (RONS). Presumably, these RONS induce an oxidative stress in cancer cells, leading to antitumor effects. These investigations constitute advances for endoscopic applications aimed at targeting cancer.
Asymmetric dual cascade in gravitational wave turbulence
- Gay Benoît
- Galtier Sébastien
Physica D: Nonlinear Phenomena, Elsevier, 2025, 477, pp.134712. (10.1016/j.physd.2025.134712)
DOI : 10.1016/j.physd.2025.134712
Ideal and resistive impurity parallel-velocity-gradient instability
- Cuerva-Lazaro G
- Lesur Maxime
- Gürcan O
- Bourgeois J
- Maestracci C
- Gravier E
- Kosuga Y
Plasma Physics and Controlled Fusion, IOP Publishing, 2025, 67 (7), pp.075019. The presence of impurity ions in magnetically confined plasmas can significantly influence micro-instabilities, impacting cross-field transport and ultimately affecting fusion performance. In particular, Parallel Velocity Gradient (PVG) instability, commonly observed at the edge of fusion devices and in linear devices, can be strongly influenced by impurities. Inspired by the drift-wave models of Hasegawa-Mima and Hasegawa-Watakani, this article develops and examines two distinct fluid models: the ideal impurity-PVG model and the resistive impurity-PVG model. These models aim to investigate the impact of impurities on key properties of the PVG instability, both in the linear and nonlinear regimes. Our findings show that non-negligible impurity concentrations change the growth rates, wave-number ranges, and nonlinear saturations of these instabilities. Notably, the degree of ionization and the relative impurity flow shear can either amplify or mitigate PVG-related turbulence, depending on the impurity and overall plasma conditions. The results underscore the need for a more comprehensive treatment of multi-ion-species plasmas, particularly when impurity fractions cannot be treated as traces. (10.1088/1361-6587/ade4fb)
DOI : 10.1088/1361-6587/ade4fb
Automated Nanosecond Plasma Jets for Targeted Medical Treatments
- Billeau Jean-Baptiste
- Radu Vlad-Stefanut
- Polprasarn Kasidapa
- Gérôme Frédéric
- Benabid Fetah
- Pai David
- Seletskiy Denis
- Reuter Stephan
- Starikovskaia Svetlana
, 2025, pp.MC14 : Sources de particules chargées, Plasmas.
Spectroscopic investigations of a filament reconnecting with coronal loops during a two-ribbon solar flare
- Joshi Reetika
- Dudík Jaroslav
- Schmieder Brigitte
- Aulanier Guillaume
- Chandra Ramesh
Astronomy & Astrophysics - A&A, EDP Sciences, 2025, 698, pp.A301. Context. In the standard 2D model of eruption, the eruption of a magnetic flux rope is associated with magnetic reconnection occurring beneath it. However, in 3D, additional reconnection geometries are possible, in particular the AR – RF , where external reconnection involving the overlying arcades ( A ) and erupting flux rope ( R ) turns into another arcade and a flare loop ( F ). This process results in the drifting of the legs of the erupting flux rope. Aims. We investigate spectroscopic signatures of such AR – RF reconnection occurring in an erupting filament reconnecting with coronal arcades during a weak B3.2-class two-ribbon flare. Methods. We examined the evolution of the erupting filament eruption using imaging observations by the Atmospheric Imaging Assembly (AIA) as well as both imaging and spectroscopic observations by the Interface Region Imaging Spectrograph (IRIS). Results. As the filament rises into the corona, it reconnects with the surrounding arcade of coronal loops with localized brightenings, resulting in the disappearance of the coronal loops and formation of a hot flux rope, showing a slipping motion of its footpoints that extends to the previous footpoints of the coronal loops ( AR – RF reconnection), as was predicted by the 3D extensions to the standard solar flare model. These brightenings are accompanied by the presence of strong blueshifts in both the IRIS Si IV and Mg II lines, up to ≈200 km s −1 . The lines are also extremely wide, with nonthermal widths above 100 km s −1 . Furthermore, a strongly non-Gaussian profile of the most blueshifted component is detected at the start of the AR – RF reconnection, indicating the presence of accelerated particles and magnetohydrodynamic turbulence, and associated with the appearance of hot plasma in the AIA 94 Å passband. Results. For the first time, an observation has been reported in which the IRIS slit successfully captures AR – RF reconnection between a filament and overlying arcades, resulting in strong blueshifts and very broad line profiles. (10.1051/0004-6361/202554011)
DOI : 10.1051/0004-6361/202554011
Cross-Analysis of Magnetic and Current Density Field Topologies in a Quiescent High Confinement Mode Tokamak Discharge
- Firpo Marie-Christine
Foundations, MDPI, 2025.
Investigating two configurations of flowing dielectric barrier discharges to trigger immune response for non-small cell lung carcinoma
- Soulier Manon
- Marmier Solenne
- Géraud Korentin
- Cremer Isabelle
- Dufour Thierry
, 2025. Non-small cell lung carcinoma (NSCLC) is a highly lethal cancer, asymptomatic in early stages and prone to rapid metastasis. Conventional therapies are unsuccessful in the major cases, except immunotherapy which can be curative for 30% of patients. Therefore, disruptive and combinative therapies should be explored to benefit a broader patient population. Recently, cold atmospheric plasma (CAP), also considered as an efficient source of reactive oxygen and nitrogen species (ROS/RNS), has shown potential to trigger immunogenic cell death, resulting in an antitumor immune response 1. In this purpose, we are investigating cold plasma processes for NSCLC therapy. Two plasma devices are designed: a dielectric capillary with outer ring electrodes, generating a plasma jet (ORJET) and a Dielectric Barrier Device with gas flowing through Mesh counter-ElectroDe (DBD-MED). Both are supplied in helium (1 L/min) and powered by a nanopulse high-voltage generator device (3-5 kV/10-20 kHz/1 %). Physical characterizations of the plasma are performed for various gap distances between the outlet of the source and an artificial model mimicking the human body electrical response (R = 1.5 kΩ // C = 100 pF 2). While the plasma plume produced by ORJET can propagate through 10 mm guaranteeing contact with the artificial model, ROS (O and OH radicals) as well as nitrogen ions N2+ quickly decrease at the vicinity of the target in favor of neutral nitrogen molecules N2. DBD-MED generates a homogenous plasma flowing afterglow beyond the grounded mesh counter-electrode in the range 0-2 mm, producing a gradient of ROS/RNS (O, OH, N2+ and nitrogen oxide NO) from the high-voltage electrode to the artificial model. Then, operating parameters are selected to ensure plasma electrical and thermal safety (I < 100 mA and T < 40°C) for subsequent experiments on murine and porcine models. Therapeutic effects of the two devices are assessed on NSCLC tumors subcutaneously grafted in immunocompetent mice exposed 5 times to plasma. Significant tumor regression is observed from the third treatment, persisting at least 20 days after the final treatment. Interestingly, the two sources have shown similar effects on tumor growth, metastasis and abscopal effect, involving an immune cell activation mediated by immunogenic cell death. We demonstrate the involvement of CD8+ T and CD20+ B cells in this antitumoral immune response. In conclusion, CAP holds strong potential to stimulate an antitumor immune response and could complement conventional immunotherapies for NSCLC treatment.
Initiation Route of Coronal Mass Ejections. II. The Role of Filament Mass
- Xing Chen
- Cheng Xin
- Aulanier Guillaume
- Ding Mingde
The Astrophysical Journal, American Astronomical Society, 2025, 986 (1), pp.37. Abstract A thorough understanding of the initiation of coronal mass ejections (CMEs), which is manifested as a slow rise of pre-eruptive structures before the impulsive ejection in kinematics, is key for forecasting solar eruptions. In our previous work, we showed that the slow rise of a hot flux rope with coronal mass density is caused by the moderate magnetic reconnection occurring in the hyperbolic flux tube (HFT) combined with the torus instability. However, it remains unclear how the initiation process varies when a filament is present in the pre-eruptive flux rope. In this work, we reveal the complete initiation route of a CME containing filament mass with a state-of-the-art full-magnetohydrodynamics simulation. The comprehensive analyses show that the filament mass has an important impact on the CME initiation through triggering and driving the slow rise of flux rope with its drainage, besides the contributions of HFT reconnection and torus instability. Finally, in combination with our previous work, we propose that the enhanced drainage of filament mass and various features related to the HFT reconnection, such as the split of pre-eruptive structure and the preflare loops and X-ray emissions, can serve as precursors of CME initiation in observations. (10.3847/1538-4357/adceb5)
DOI : 10.3847/1538-4357/adceb5
Evolution of Solar Wind Turbulence during Radial Alignment of Parker Solar Probe and Solar Orbiter in 2022 December
- Silwal Ashok
- Zhao Lingling
- Zhu Xingyu
- Sorriso-Valvo Luca
- Hadid Lina
- Zank Gary
- Li Hui
- Badman Samuel
- Rivera Yeimy
- Gautam Sujan Prasad
- Karki Monika
- Alonso Guzman Juan
- M. Subashchandar Nibuna
- Jin Zeping
The Astrophysical Journal Supplement Series, IOPscience, 2025, 278 (2), pp.40. Abstract We investigate the radial evolution of solar wind turbulence during the radial alignment of Parker Solar Probe (PSP) and Solar Orbiter (SO) on 2022 December 10, with PSP located at approximately 0.11 au and SO near 0.88 au. To identify nearly the same plasma parcel crossing both spacecraft, we apply a ballistic propagation model with time-constant acceleration constrained by in situ solar wind velocity measurements at PSP and SO. We trace the magnetic footpoint of the plasma parcel back to the photosphere using a potential field source surface model based on a Global Oscillations Network Group synoptic magnetogram. Field and plasma measurements from PSP and SO are used to analyze power spectral density (PSD), spectral scaling, magnetic compressibility, and intermittency. Our results show that (1) the trace PSD of magnetic fluctuations steepens in the inertial range and flattens in the dissipation range with increasing radial distance; (2) the spectral break shifts to lower frequencies at SO; and (3) the Castaing model reveals multifractal intermittency in the inertial range, with slightly weaker intermittency at SO. These findings based on the same plasma parcel are consistent with the results of statistical studies on the radial evolution of turbulence and provide a reference for theoretical modeling of turbulence in the inner heliosphere. (10.3847/1538-4365/add011)
DOI : 10.3847/1538-4365/add011
Investigation of filamentary and diffuse DBD in CO 2 by means of in-situ FTIR absorption spectroscopy
- Bajon Corentin
- Baratte Edmond
- Sadi Dihya
- Guaitella Olivier
- Belinger Antoine
- Dap Simon
- Hoder Tomas
- Naudé Nicolas
, 2025. This work investigates CO2 dielectric barrier discharges at atmospheric pressure in the filamentary and diffuse regimes for the first time using in situ FTIR absorption measurements. The conversion factor of CO2 is determined and is consistent with the results obtained for DBDs in the literature. Vibrational temperatures for CO2 and CO molecules are also determined, as well as the rotational temperature. The ordering of the different temperatures is similar to the reported results for other CO2 discharges. The evolution of the measured parameters as a function of the specific energy input is discussed and a comparison of the two different regimes is carried out.
Rapport de conjoncture de la Section 17 "SYSTÈME SOLAIRE ET UNIVERS LOINTAIN" du Comité National de la Recherche Scientifique - Mandature 2021-2025
- Motte Frederique
- Famaey Benoit
- Lamy Laurent
- Aghanim Nabila
- Baklouti Donia
- Bournaud Frédéric
- Cambrésy L.
- Codis Sandrine
- Issautier Karine
- Leconte Jérémy
- Mirioni Laurent
- N'Diaye Mamadou
- Oertel Micaela
- Palacios Ana
- Recio-Blanco Alejandra
- Roy Fabrice
- Theureau Gilles
- Savalle Renaud
- Tibaldo Luigi
- Tresse Laurence
- Vincent F
- Caffau Elisabetta
- Douet Richard
- Laibe Guillaume
- Regimbau Tania
- Reylé Céline
, 2025. Ce rapport s'adresse à un lectorat non expert de la discipline Astrophysique, souhaitant avoir un aperçu de l'évolution de notre communauté de recherche au sein de CNRS INSU (Institut National des Sciences de l'Univers, également appelé CNRS Terre & Univers) sur la période 2022-2024. Il présente un résumé thématique et méthodologique de nos activités, un panorama de la structuration actuelle de notre communauté, ainsi qu'un bilan des recrutements et des promotions. Il est fondé sur le travail de la section 17, lequel comprend les concours de recrutement, les recrutements contractuels RQTH, la carrière (évaluation, promotion, éméritat, demande de rattachement à la section ou de détachement de celle-ci, changement d'affectation et RIPEC C3) des personnels de recherche rattachés à la section 17 ; l'évaluation des structures rattachées à la section 17 ; les propositions pour les médailles d'argent et de bronze du CNRS ; les demandes d'accueil en délégation au CNRS ; les écoles thématiques.
Quantitative estimates of the magnetic flux variations in the inner magnetosphere during an intense storm.
- Alqeeq Soboh
- Fontaine Dominique
- Le Contel Olivier
- Akhavan-Tafti Mojtaba
- Cazzola Emanuele
- Atilaw Tsige
, 2025. In the present study, we analyzed the Earth's magnetospheric dynamics in response to the intense geomagnetic storm of 19th December 2015, marked by a substantial decrease in the SYM-H index to -188 nT. We focushere on the variations of the magnetic flux content (MFC) within closed magnetic shells in the inner magnetosphe up to a distance roughly corresponding to the magnetopause. During this event, we had the chance to have observations on the dayside and on the nightside and at different distances in the magnetosphere (OMNI, Van Allen Probes, GOES, THEMIS, MMS, Cluster). Using these various observations together with the Tsyganenko T96 model, we estimated the MFC in the inner magnetosphere. It is found that in comparison to pre-storm conditions, MCF decreased during SSC by 17% and in the main phase by 27% but it gradually rebounded (swelled) during 3 following days of the recovery phase reducing the decrease to 22%, 14% and 8% respectively. The importance of storm-time magnetospheric dynamics in the field of space weather forecasting is emphasized by these findings and calls for further studies. (10.5194/egusphere-egu25-8724)
DOI : 10.5194/egusphere-egu25-8724

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