Scientific publications

2025

• Absolute calibration and quantification of atomic oxygen in nanosecond plasmas using two-photon absorption laser-induced fluorescence
  
  • Shu Zhan
  , 2025. Atomic oxygen is commonly generated in reactive media, such as low-temperature plasmas and combustion environment. Owing to its high chemical reactivity and consequent short lifetime, time- and space-resolved measurements of O-atom density are essential for elucidating particle kinetic behavior and reaction mechanisms. Two-photon absorption laser-induced fluorescence (TALIF) has emerged as a powerful non-intrusive technique for detecting atomic species. By employing fast (nanosecond) and ultra-fast (picosecond or femtosecond) laser pulses, this technique enables the excitation of ground-state atoms and the detection of their subsequent fluorescence, offering excellent temporal and spatial resolution. When properly calibrated, TALIF allows absolute quantification over a dynamic range.A significant challenge in the calibration of O-TALIF lies in the uncertainty associated with the two-photon absorption cross-section ratio between the reference gas xenon and atomic oxygen. This ratio was determined by only one group of authors and has been widely used for twenty years. However, recent studies have indicated that this value may lead to an overestimation of the atomic oxygen density. Another issue happens when applying ultra-fast TALIF, which is especially well-suited for diagnosing transient plasmas characterized by strong collisional quenching at high pressures. Under conditions of high laser power density, the rate-equation-based model may overestimate the excited-state population, and thus the inferred ground-state density, due to the omission of coherence effects and saturation phenomena.This thesis proposed a novel approach to calibrate the two-photon absorption cross-section ratio of Xe/O in nanosecond TALIF application. A nanosecond pulsed discharge, applied within a millimeter-scale capillary tube, enables efficient molecular dissociation at high reduced electric field and high specific deposited energy. Notably, complete dissociation of molecular oxygen was achieved in the afterglow of a N2+5%/2% O2 discharge at moderate pressure, providing a practical and well-characterized source of atomic oxygen. Then the known density served as a robust calibration reference for the Xe/O cross-section ratio. A developed one-dimensional numerical simulation was used to verify the 100% oxygen dissociation, compare with the experimental data, and analyze the formation pathways of atomic oxygen. Electrical diagnostics were employed by back-current shunt and capacitive probe techniques, while gas temperature was determined using optical emission spectroscopy. These measurements helped to characterize and customize the discharge, forming the basis for kinetic modeling and the validation of calculation results.The calibration work of Xe/O cross-section ratio was subsequently extended to picosecond TALIF measurements. Compared to nanosecond TALIF, the picosecond pulsed laser offers a more efficient excitation of ground-state oxygen atoms. The Xe/O cross-section ratio was confirmed to be 1.8 for both nanosecond and picosecond regimes, with uncertainties of ±0.2 and ±0.3, respectively. The validity range of the rate equations and the conditions under which a transition to the optical Bloch equations becomes necessary were discussed.Further applications of O-TALIF were explored, emphasizing its capability for time- and space-resolved diagnostics. The temporal evolution of atomic oxygen in the afterglow of nanosecond capillary discharges in CO2 was measured to validate the kinetic model and provide insights into the dissociation pathways at high reduced electric field and high specific deposited energy. The implementation of absolute calibration in the nanosecond varying-gap plane-to-plane discharge confirmed the formation of an O-atom density gradient, which may play a critical role in the initiation and propagation of detonation waves. (10.70675/8cb96554zb67cz4400z94eaz49620a743032)
  DOI : 10.70675/8cb96554zb67cz4400z94eaz49620a743032
• 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
  The Journal of physical chemistry, American Chemical Society (ACS), 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. (10.1021/acs.jpcc.5c02224)
  DOI : 10.1021/acs.jpcc.5c02224
• Comparing PIC/MCC Simulations and Experimental Data for the PPS ® X00-ML Hall Thruster IEPC
  
  • Petronio Federico
  • Laguna Alejandro Alvarez
  • Bourdon Anne
  • Chabert Pascal
  • Laurent Benjamin
  , 2025. <div><p>Validating simulation results against experimental measurements of Hall thruster (HT) performance has long been a major challenge. Few examples of successful comparison do exist in the literature. In this work, we compare the results of three codes: (1) fluid stationary, (2) fluid non-stationary, and (3) two dimensional Particle-in-Cell/Monte Carlo-Collisions (PIC/MCC), with experimental measurements on the Laboratory Model (ML) thruster PPS ® X00-ML HT by Safran Spacecraft Propulsion. The results show that fluid and PIC/MCC simulations can successfully reproduce some macroscopic measured quantities, such as discharge current, thrust, and specific impulse. Simulations also offer the possibility to inquire the state of the plasma inside the thruster, gaining a deeper insight on the plasma characteristics along the thruster axis.</p></div>
• 2D hybrid simulations of Hall Thrusters: effect of self-consistently generated multiply charged ions
  
  • Amadio Pierre
  • Petronio Federico
  • Bourdon Anne
  • Chabert Pascal
  , 2025. Hall Thrusters (HTs) enable in-space mobility using E × B plasma discharge principles. Presence of multiply charged ions in these devices has been repeatedly observed, and reported to affect thruster operation. In this study, we examine the impact of doubly charged ions using a two-dimensional hybrid particle-in-cell/Monte Carlo collision (PIC/MCC) simulation of the SPT-100 thruster. The simulation operates at an anode voltage of 500 V and a xenon mass flow rate of 5 mg/s. Double ionization of neutral xenon and single ionization of Xe+ are incorporated as mechanisms for self-consistent Xe2+ generation.Both processes are found to be of comparable significance. Breathing mode oscillations are captured by the model and shown to modulate differently the two Xe2+ production pathways. Results show that Xe2+ ions contribute approximately to 17 % of the total discharge current, and that their presence leads to higher discharge current, thrust, and specific impulse.
• Convolutions on partially regular recurrent lattices
  
  • Gürcan Ö.D.
  • Manfredini L.
  Communications in Nonlinear Science and Numerical Simulation, Elsevier, 2025, 152, pp.109262. Partially regular recurrent lattices, are k-space grids that we propose, which consist of a central regular region that is extended using a recurrence relation, resulting in an asymptotically logarithmic lattice structure. Such a lattice can be used to model the turbulent cascade over a very large range of scales covered by the recurrent part, while keeping the large scale eddies mainly in the regular part. Here we propose a novel pseudo-spectral algorithm for computing the convolutions over such a lattice, using an overlapping partition of its different parts, using the fact that the interactions in the recurrent part of the lattice are limited, in each direction, to a small number of elements linked through the recurrence relation. We compare the results with a full grid, dense, fast Fourier transform (fft) based convolution, where the nonexistent elements on the full grid are set to zero, and show that the difference remains within a few orders of the machine precision. The algorithm in two dimensions uses one fft for the regular grid, and bunch of smaller ffts for the rest of the points, either elongated to match the length of the regular part of the grid in one dimension or even smaller ffts (typically) to include the interactions between recurrent parts of the lattice. The algorithm can be trivially generalized to arbitrary number of dimensions. (10.1016/j.cnsns.2025.109262)
  DOI : 10.1016/j.cnsns.2025.109262
• Influence of chemical and morphological properties on the mid-infrared refractive indices of Titan aerosol analogs
  
  • Perrin Zoé
  • Drant Thomas
  • Garcia-Caurel Enrique
  • Brubach Jean-Blaise
  • Ruscassier Nathalie
  • Gautier Thomas
  • Sciamma-O’brien Ella
  • Vettier Ludovic
  • Chatain Audrey
  • Guaitella Olivier
  • Carrasco Nathalie
  , 2025. In the atmosphere of Saturn's largest satellite, Titan, the solid particles in suspension (photochemistry organic aerosols) play an important role notably to the attenuation of the solar spectrum by absorption and scattering. To constrain these interactions, the optical properties of Titan’s atmospheric aerosols, refractive index n and extinction coefficient k were recovered from observations [1, 2, 3, 4]. The refractive indices database has been expanded using solid analogs of Titan's aerosols produced and analyzed in laboratory [5, 6, 7]. The experimental data are generally consistent with the optical properties derived from Titan’s aerosols, including the contribution to the extinction and albedo of Saturn's moon [5, 7, 8]. However, comparisons of vibrational modes in the mid-infrared (MIR) suggest a difference in composition between laboratory analogs and Titan’s aerosols [9, 10]. These discrepancies in the refractive indices of solids can originate from their morphological and chemical properties. Indeed, numerous experimental studies have revealed the variability in the morphology and chemical composition of solid analogs formed in simulations of Titan's atmospheric chemistry. (10.5194/epsc-dps2025-904)
  DOI : 10.5194/epsc-dps2025-904
• Development of a Cold Plasma Process to Isolate Archaeal Lipid Biomarkers In Halite Fluid Inclusions
  
  • Pezeau Léa
  • Kish Adrienne
  • Dufour Thierry
  • Grossi Vincent
  • Coffinet Sarah
  • Joreau Emelyne
  • Anquetil Christelle
  • Huguet Arnaud
  , 2025. Lipid membrane adaptations under extreme salinity conditions are essential to maintain cellular integrity and metabolic processes in Halobacterium. salinarum. We aim to study the mechanisms of adaptation of the lipidome of the archaeal H. salinarum to hypersaline conditions during halite crystal formation, which will provide key information on the potential preservation of lipid biosignatures over geological time. It is essential to ensure that the lipids detected within the halite crystals are only those of H. salinarum and do not correspond to organic residues on the surface of the halites. To this end, we investigated the effectiveness of cold plasma in removing organic compounds potentially present on the surface of halites. Whatever the conditions of the cold plasma treatment, the residual amount of archaeol, the main membrane lipid of H. salinarum, in the treated crystals vs. the untreated ones was in average less than 5%. This shows for the first time the efficiency of such a treatment in removing the archaeal cells at the surface of halite crystals. This protocol has now to be tested on crystals inoculated with H. salinarum both internally and externally to ensure that only the lipids entrapped within the inclusion are preserved after the treatment. (10.3997/2214-4609.202533292)
  DOI : 10.3997/2214-4609.202533292
• Comparison of Leak Sensors for Detection Sensitivity in a Vacuum Chamber: Self-Plasma Optical Emission Spectroscopy and Residual Gas Analyzer
  
  • Cho Chulhee
  • Kim Sijun
  • Lee Isak
  • Lee Youngseok
  • Cha Soonyong
  • Cha Dongho
  • You Shinjae
  IEEE Sensors Journal, Institute of Electrical and Electronics Engineers, 2025, 25 (17), pp.33765-33778. Since leak in the semiconductor fabrication process is one of the potential threats causing device degradation, it is significant to evaluate the leak detection performance of current leak sensors for advancing leak detection technology. In this study, we evaluated the leak detection performance of widely used leak sensors: self-plasma optical emission spectroscopy (SPOES) and residual gas analyzer (RGA). Specifically, we examined two SPOES systems: 1) SPOES-i, which employs an inductively coupled plasma source, and 2) SPOES-c, which employs a capacitively coupled plasma source. Leak is injected into a vacuum chamber with an Ar background gas, using a mass flow controller (MFC) with concentrations ranging from 2.0 to 20 ppm. Before evaluation, we found the optimal operating conditions for each sensor in detail. We then evaluated their leak detection performance, limit of detection (LoD), and sensitivity at chamber pressures of 6.7 Pa (50 mTorr), 13.3 Pa (100 mTorr), and 26.7 Pa (200 mTorr). In terms of the LoD, the experimental results demonstrated that, at 6.7 Pa, the SPOES-c detects the leak concentrations as low as 2.0 parts per million (ppm), while the SPOES-i and the RGA detected between 2.4 and 6.0 ppm. At higher pressures (>6.7 Pa), all three sensors detected at least 2.0 ppm. This enhancement of the detection limit results from the increase in the absolute leak amount with higher chamber pressure at the same concentration. In terms of sensitivity, the SPOES-i exhibited the highest value, followed by SPOES-c, and then the RGA. It might result from the fact that the sensitivity is proportional to the density of electrons of each sensor, the higher the electron density, the larger the sensitivity. Detailed discussions on LoD and sensitivity are provided. These findings will contribute to the future development of in situ leak detection for sub-ppm level leak detection. (10.1109/JSEN.2025.3587648)
  DOI : 10.1109/JSEN.2025.3587648
• Broadband mid-infrared spectroscopy in a CH4 + O2 plasma glow discharge
  
  • Briend Malo
  • Budde Maik
  • Guaitella Olivier
  • Rutkowski Lucile
  , 2025.
• Time-resolved mid-infrared frequency comb spectroscopy in CO2 plasma environments
  
  • Briend Malo
  • Sadi Dihya
  • Guaitella Olivier
  • Rutkowski Lucile
  , 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_⊥∣²/∣E∣² of beam-generated turbulent Langmuir/Z-mode ($\mathcal{LZ}$) waves and electromagnetic emissions radiated at plasma frequency ω_p 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_p 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
• Radiation efficiency of electromagnetic wave modes from beam-generated solar radio sources
  
  • Krafft C.
  • Volokitin A S
  • Polanco-Rodríguez F J
  • Savoini P.
  Nature Astronomy, Nature Publishing Group, 2025, 9 (9), pp.1292-1299. <div xmlns="http://www.tei-c.org/ns/1.0"><p>During Type III solar radio bursts, electromagnetic waves are radiated at plasma frequency ωp and its harmonics by electrostatic wave turbulence generated by electron beams ejected by Sun in randomly inhomogeneous solar wind and coronal plasmas. These emissions, detected since decades by spacecraft and radiotelescopes, are split by the plasma magnetic field into three modes X , O and Z of different dispersion, polarization and radiation properties. This work demonstrates, using three independent and converging approaches, that only a small fraction of electromagnetic energy radiated at ωp (≲ 10%) is escaping from beam-generated radio sources, mainly as Omode waves and, depending on plasma conditions, as X -mode waves. Most energy is radiated in Z-mode and can therefore be only observed close to sources. Results have major implications for solar radio emission and provide strong support for interpretation of observations performed up to close distances to Sun by Parker Solar Probe and Solar Orbiter spacecraft.</p></div> (10.1038/s41550-025-02619-2)
  DOI : 10.1038/s41550-025-02619-2
• 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
• FlashSim: A novel particle-in-cell numerical model for vacuum surface flashover simulation based on finite element method
  
  • Liu Hao-Yan
  • Sun Guang-Yu
  • Liu Yue-Lin
  • Zhang Shu
  • Qi Chang-Chun
  • Zhou Sheng
  • Li Wen-Rui
  • Zhang Guan-Jun
  Computer Physics Communications, Elsevier, 2025, 313, pp.109625. In vacuum-dielectric insulation systems, surface flashover is commonly considered as an interfacial breakdown induced by high electric field, posing a significant threat to the stable and safe operation of numerous vacuum equipment. To clarify its development mechanism and propose relevant suppression strategies, a novel Particle-in-Cell (PIC) vacuum surface flashover simulation model, FlashSim, based on finite element method (FEM), is introduced. The model computes the real-time electric field at cathode triple junction (CTJ) where seed electrons are generated. Electron collisions with the dielectric surface, including elastic backscattering, inelastic backscattering, and true secondary electron emission, are considered. Firstly, the flashover simulation with flat dielectric surface and parallel-plate electrodes shows that electric field at CTJ is enhanced due to surface charge accumulation, leading to an increase in field electron emission (FEE). Low-energy (&lt;53 eV) electrons concentrate near the dielectric surface due to positive charging in the dielectric layer, while high-energy (53eV-1.9 keV) electrons can escape into higher vertical positions. Furthermore, the model employs adaptive mesh, enabling high simulation accuracy without compromising the computational time. Notably, the adopted FEM mesh generator can handle complex boundary geometries, which is validated by simulations with surface grooving for promoting the flashover capability. The performance of grooves is evaluated through electron distribution, anode current density, average surface charge density and electron flux, demonstrating higher flashover strength. The proposed FlashSim simulation model is expected to assist in further revealing the flashover mechanism and developing novel strategies for flashover suppression, and will be further upgraded to include outgassing and plasma discharge. (10.1016/j.cpc.2025.109625)
  DOI : 10.1016/j.cpc.2025.109625
• 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
• 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.
• 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.
• 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.
• 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.
• 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
• Ion and Plasma Diagnostics
  
  • Bacal Marthe
  • Sasao Mamiko
  • Wada Motoi
  , 2025, 127, pp.33-68. The fundamentals of ion and plasma diagnostics are introduced with some actual examples. For the purpose of elucidating the important role of a diagnostic method in establishing physics-based models, the implementation of negative ion density measurements using laser-induced photodetachment is described, and applications of the method to study negative ion containing plasmas are explained. Possibilities of using particle beams are discussed for the future applications on ions and plasma diagnostics. Advancements of particle sources, light sources, measurement electronics, and digital data processing support the development of diagnostics techniques for emerging applications of ion beams and plasmas. (10.1007/978-3-031-84245-0_3)
  DOI : 10.1007/978-3-031-84245-0_3
• 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
• 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.