Publications

2023

• Editorial: New challenges in space plasma physics: Open questions and future mission concepts
  
  • Sorriso-Valvo Luca
  • Chen Christopher
  • Retinò Alessandro
  • Verscharen Daniel
  Frontiers in Astronomy and Space Sciences, Frontiers Media, 2023, 9, pp.1130728. (10.3389/fspas.2022.1130728)
  DOI : 10.3389/fspas.2022.1130728
• Observations of Kolmogorov Turbulence in Saturn's Magnetosphere
  
  • Xu S B
  • Huang S Y
  • Sahraoui Fouad
  • Yuan Z G
  • Wu H H
  • Jiang K.
  • Zhang J.
  • Lin R T
  Geophysical Research Letters, American Geophysical Union, 2023, 50 (16), pp.e2023GL105463. The Kolmogorov scaling in the inertial range of scales is a distinct characteristic of fully developed turbulence, and studying it offers valuable insights into the evolution of turbulence. In this work, we perform a statistical survey of the power spectra with the Kolmogorov scaling in Saturn's magnetosphere using Cassini measurements. Two cases study show that both magnetic‐field and electron density spectra exhibit f^−5/3 at the MHD scales. The statistical analysis reveals a wide‐ranging and abundant presence of Kolmogorov spectra throughout magnetosphere, observed across all local times. Interestingly, the occurrence rate of these Kolmogorov‐like events within Saturn's magnetosphere surpasses that observed in the planetary magnetosheath. The measurements of magnetic compressibility for the Kolmogorov‐like events show the dominance of incompressible Alfvénic turbulence (44.64%) with respect to magnetosonic‐like one (6.94%). In addition, the source and evolution of the turbulent fluctuations are further discussed. (10.1029/2023GL105463)
  DOI : 10.1029/2023GL105463
• Conditions for Inception of Relativistic Runaway Discharges in Air
  
  • Pasko Victor
  • Celestin Sebastien
  • Bourdon Anne
  • Janalizadeh Reza
  • Jansky Jaroslav
  Geophysical Research Letters, American Geophysical Union, 2023, 50 (7), pp.e2022GL102710. Terrestrial gamma-ray flashes are linked to growth of long bidirectional lightning leader system consisting of positive and stepping negative leaders. The spatial extent of streamer zones of a typical lightning leader with tip potential exceeding several tens of megavolts is on the order of 10–100 m. The photoelectric absorption of bremsstrahlung radiation generated by avalanching relativistic runaway electrons occurs efficiently on the same spatial scales. The intense multiplication of these electrons is triggered when the size of the negative leader streamer zone crosses a threshold of approximately 100 m (for sea-level air pressure conditions) allowing self-replication of these avalanches due to the upstream relativistic electron seeds generated by the photoelectric absorption. The model results also highlight importance of electrode effects in interpretation of X-ray emissions from centimeter to meter long laboratory discharges, in particular, a similar feedback effect produced by generation of runaway electrons from the cathode material. (10.1029/2022GL102710)
  DOI : 10.1029/2022GL102710
• Comparison of magnetic energy and helicity in coronal jet simulations
  
  • Pariat Etienne
  • Wyper P F
  • Linan L.
  Astronomy & Astrophysics - A&A, EDP Sciences, 2023, 669, pp.A33. Context. While non-potential (free) magnetic energy is a necessary element of any active phenomenon in the solar corona, its role as a marker of the trigger of the eruptive process remains elusive. Meanwhile, recent analyses of numerical simulations of solar active events have shown that quantities based on relative magnetic helicity could highlight the eruptive nature of solar magnetic systems. Aims. Based on the unique decomposition of the magnetic field into potential and non-potential components, magnetic energy and helicity can also both be uniquely decomposed into two quantities. Using two 3D magnetohydrodynamics parametric simulations of a configuration that can produce coronal jets, we compare the dynamics of the magnetic energies and of the relative magnetic helicities. Methods. Both simulations share the same initial setup and line-tied bottom-boundary driving profile. However, they differ by the duration of the forcing. In one simulation, the system is driven sufficiently so that a point of no return is passed and the system induces the generation of a helical jet. The generation of the jet is, however, markedly delayed after the end of the driving phase; a relatively long phase of lower-intensity reconnection takes place before the jet is eventually induced. In the other reference simulation, the system is driven during a shorter time, and no jet is produced. Results. As expected, we observe that the jet-producing simulation contains a higher value of non-potential energy and non-potential helicity compared to the non-eruptive system. Focussing on the phase between the end of the driving-phase and the jet generation, we note that magnetic energies remain relatively constant, while magnetic helicities have a noticeable evolution. During this post-driving phase, the ratio of the non-potential to total magnetic energy very slightly decreases while the helicity eruptivity index, which is the ratio of the non-potential helicity to the total relative magnetic helicity, significantly increases. The jet is generated when the system is at the highest value of this helicity eruptivity index. This proxy critically decreases during the jet-generation phase. The free energy also decreases but does not present any peak when the jet is being generated. Conclusions. Our study further strengthens the importance of helicities, and in particular of the helicity eruptivity index, to understand the trigger mechanism of solar eruptive events. (10.1051/0004-6361/202245142)
  DOI : 10.1051/0004-6361/202245142
• HelioSwarm: A Multipoint, Multiscale Mission to Characterize Turbulence
  
  • Klein Kristopher
  • Spence Harlan
  • Alexandrova Olga
  • Argall Matthew
  • Arzamasskiy Lev
  • Bookbinder Jay
  • Broeren Theodore
  • Caprioli Damiano
  • Case Anthony
  • Chandran Benjamin
  • Chen Li-Jen
  • Dors Ivan
  • Eastwood Jonathan
  • Forsyth Colin
  • Galvin Antoinette
  • Genot Vincent
  • Halekas Jasper
  • Hesse Michael
  • Hine Butler
  • Horbury Tim
  • Jian Lan
  • Kasper Justin
  • Kretzschmar Matthieu
  • Kunz Matthew
  • Lavraud Benoit
  • Contel Olivier Le
  • Mallet Alfred
  • Maruca Bennett
  • Matthaeus William
  • Niehof Jonathan
  • O'Brian Helen
  • Owen Christopher
  • Retino Alessandro
  • Reynolds Christopher
  • Roberts Owen
  • Schekochihin Alexander
  • Skoug Ruth
  • Smith Charles
  • Smith Sonya
  • Steinberg John
  • Stevens Michael
  • Szabo Adam
  • Tenbarge Jason
  • Torbert Roy
  • Vasquez Bernard
  • Verscharen Daniel
  • Whittlesey Phyllis
  • Wickizer Brittany
  • Zank Gary
  • Zweibel Ellen
  Space Science Reviews, Springer Verlag, 2023. HelioSwarm (HS) is a NASA Medium-Class Explorer mission of the Heliophysics Division designed to explore the dynamic three-dimensional mechanisms controlling the physics of plasma turbulence, a ubiquitous process occurring in the heliosphere and in plasmas throughout the universe. This will be accomplished by making simultaneous measurements at nine spacecraft with separations spanning magnetohydrodynamic and sub-ion spatial scales in a variety of near-Earth plasmas. In this paper, we describe the scientific background for the HS investigation, the mission goals and objectives, the observatory reference trajectory and instrumentation implementation before the start of Phase B. Through multipoint, multiscale measurements, HS promises to reveal how energy is transferred across scales and boundaries in plasmas throughout the universe. (10.3847/25c2cfeb.84e839d7)
  DOI : 10.3847/25c2cfeb.84e839d7
• Two-dimensional effects on electrostatic instabilities in Hall thrusters. I. Insights from particle-in-cell simulations and two-point power spectral density reconstruction techniques
  
  • Petronio Federico
  • Charoy Thomas
  • Alvarez Laguna Alejandro
  • Bourdon Anne
  • Chabert Pascal
  Physics of Plasmas, American Institute of Physics, 2023, 30 (1), pp.012103. Using 2D particle-in-cell (PIC) simulations coupled to a fluid description of the gas dynamics, we study the electrostatic instabilities developing in the axial–azimuthal plane of a Hall thruster, during several periods of a low-frequency oscillation (the so-called breathing mode at [Formula: see text]). As done in experiments, the 2D PIC-MCC (Monte Carlo collision) code is coupled to an electrical circuit in order to partially damp the (otherwise large) discharge current fluctuations at the breathing mode frequency. The different electrostatic higher frequency modes that develop in the plasma are analyzed using a two-point power spectral density reconstruction method, which allows us to generate the dispersion diagrams (in the frequency-wavenumber space) along the axial and azimuthal directions and at different times during the low-frequency breathing mode oscillations. This technique allows us to distinguish between different well-identified instabilities: the electron cyclotron drift instability and its evolution toward an ion acoustic wave and the ion transit time instability. These instabilities are usually considered unidirectional (either axial or azimuthal); however, it is shown here that they exist in both directions. This two-dimensional character is instrumental in understanding where these instabilities grow and how they propagate in the thruster channel and plume. A theoretical discussion of this aspect is proposed in Paper II. The effects of (i) the azimuthal length of the simulation box and (ii) the electron temperature injection at the cathode are also discussed. (10.1063/5.0119253)
  DOI : 10.1063/5.0119253
• Enabling technologies for planetary exploration
  
  • Grande Manuel
  • Guo Linli
  • Blanc Michel
  • Alves Jorge
  • Makaya Advenit
  • Asmar Sami
  • Atkinson David
  • Bourdon Anne
  • Chabert Pascal
  • Chien Steve
  • Day John
  • Fairén Alberto
  • Freeman Anthony
  • Genova Antonio
  • Herique Alain
  • Kofman Wlodek
  • Lazio Joseph
  • Mousis Olivier
  • Ori Gian Gabriele
  • Parro Victor
  • Preston Robert
  • Rodriguez-Manfredi Jose
  • J. Sterken Veerle
  • Stephenson Keith
  • Hook Joshua Vander
  • Waite J. Hunter
  • Zine Sonia
  , 2023, pp.249-329. (10.1016/B978-0-323-90226-7.00002-7)
  DOI : 10.1016/B978-0-323-90226-7.00002-7
• CO2/CH4 Glow Discharge Plasma: Part I—Experimental and Numerical Study of the Reaction Pathways
  
  • Baratte Edmond
  • Garcia-Soto Carolina A.
  • Silva Tiago
  • Guerra Vasco
  • Parvulescu Vasile I.
  • Guaitella Olivier
  Plasma Chemistry and Plasma Processing, Springer Verlag, 2023. (10.1007/s11090-023-10421-z)
  DOI : 10.1007/s11090-023-10421-z