Ftpp Publications & Presentations

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Publication DateTitleAuthorsDOI / Presentation AbstractType of PublicationFTPP SupportJournal / Conference, etc. NameAbstract
10/10/2025Magnetic Turbulence Intermittency and Compressibility in the Inner Heliosheath and Very Local Interstellar MediumL.-L. Zhao, V. Florinski, G. P. Zank, M. Opher, J. Richardson, W. S. Kurth, A. Silwal, X. Zhu, N. S. M. Subashchandar, J. G. Alonso GuzmanMore InformationJournal or Juried Conf PaperPartialThe Astrophysical Journal LettersWe analyze Voyager 1 magnetic field data through 2024 to study fluctuations from the inner heliosheath into the very local interstellar medium (VLISM). We focus on inertial-range intermittency and magnetic compressibility and examine the effects of interstellar shocks and pressure fronts. The heliosheath shows consistently high fluctuation amplitude (δB/B0 ∼ 1) and compressibility, indicating the presence of compressive wave modes...
9/22/2025Hybrid kinetic-fluid methods of plasma modelingVladimir KolobovMore InformationPresentationPrimaryAVS International Symposium and Exhibition
10/1/2025Parallel and Perpendicular Diffusion of Energetic Particles in the Near-Sun Solar Wind Observed by Parker Solar ProbeNibuna S. M. Subashchandar, Lingling Zhao, Andreas Shalchi, Gary Zank, Jakobus Le Roux, Hui Li, Xingyu Zhu, Ashok Silwal and Juan G. Alonso GuzmanMore InformationJournal or Juried Conf PaperPartialThe Astrophysical Journal LettersWe investigate energetic particle diffusion in the inner heliosphere (∼0.06–0.3 au) explored by Parker Solar Probe (PSP). Parallel (κ∥) and perpendicular (κ⊥) diffusion coefficients are calculated using second-order quasi-linear theory (SOQLT) and unified nonlinear transport theory, respectively. PSP’s in situ measurements of magnetic turbulence spectra, including sub-Alfvénic solar wind, are decomposed into parallel and perpendicular wavenumber spectra via a composite two-component turbulence model...
9/3/2025One-Dimensional Analytical Solutions of the Transport Equations for Incompressible Magnetohydrodynamic (MHD)TurbulenceBingbing Wang, Gary P. Zank, Laxman Adhikari, and Swati SharmaMore InformationJournal or Juried Conf PaperPartialGalaxies (MDPI)We derive one-dimensional (1D) analytical solutions for the transport equations of incompressible magnetohydrodynamic (MHD) turbulence, including the Elsässer energies and the correlation lengths. The solutions are suitable for an arbitrary given background convection speed and Alfvén speed profiles but require near equipartition of turbulent kinetic energy and magnetic field energy. These analytical solutions provide a simple tool to investigate the evolution of turbulence and resulting energetic particle diffusion coefficients in various space and astrophysical environments that possess simple geometry...
8/10/2025Characterization of the Transmission and Generation of Turbulence at Interplanetary ShocksSujan Prasad Gautam, Gary P Zank, Prashant Baruwal, Alexander Pitňa, Prashrit Baruwal, Laxman Adhikari, Monika Karki, Lingling Zhao, Ismita Tasnim, Ashok Silwal, and Binod AdhikariMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalWe study the transmission and characteristics of turbulent magnetohydrodynamic (MHD) fluctuations from upstream to downstream regions of interplanetary (IP) shocks using the linear mode decomposition (LMD) technique of G. P. Zank et al. We perform a superposed epoch analysis (SEA) of 84 fast-forward quasiperpendicular shock events observed by the Wind spacecraft at 1 au...
8/10/2025Influence of Solar Cycle on Magnetohydrodynamic Turbulent Modes at 1auSujan Prasad Gautam, Gary P. Zank, Laxman Adhikari, Alexander Pitňa, and Ashok SilwalMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalWe study the effect of the solar cycle on various magnetohydrodynamic (MHD) fluctuation modes using the linear mode decomposition technique developed by G. P. Zank et al. We decompose various MHD modes, including propagating modes: Alfvén (forward and backward), fast (forward and backward), and slow (forward and backward) modes, as well as nonpropagating structures: entropy and magnetic island modes, from solar wind intervals during both the minimum and maximum phases of solar cycle 23...
8/4/2025Nanoparticulate Copper Cluster-Mediated Biosensing of Cardiac Biomolecular MarkersLakshmi V Nair, Jarred Wheeler, Yaelyn Ha, Kimberly M Jones, Jesse Jones, Vinoy ThomasMore InformationJournal or Juried Conf PaperPartialBiosensorsBeing a leading cause of death, heart diseases across the globe need special attention to enable early diagnosis. Metal nanoparticle-mediated biosensors are useful clinical tools for the early detection of bio-analytes. The size-dependent surface plasmon resonance (SPR) of metal nanoparticles can be effectively utilized for the same purpose. The early detection of heart diseases can be evaluated by monitoring the troponin level...
7/24/2025Self-organization processes in low-temperature plasmasVladimir KolobovMore InformationPresentationPartialInternational Conference on Phenomena in Ionized Gases 36th Edition
7/21/2025Nonlinear kinetic simulations of Jeans instability in a magnetized dusty plasmaMasaru Nakanotani, Luis Lazcano Torres, Gary P. Zank, and Edward Thomas, Jr.More InformationJournal or Juried Conf PaperPartialAmerican Physical Society Physical Review EThe Jeans instability in a magnetized dusty plasma is considered a fundamental process in space, where magnetic fields are common. We investigate the Jeans instability in a magnetized dusty plasma using 1D and 2D particle-in-cell simulations, in which dust grains are treated as particles and the Poisson's equation for the corresponding gravitational and electrostatic potentials is solved in a self-consistent manner. We first confirm that when the magnitude of the dust cyclotron frequency is larger than the Jeans frequency, the Jeans instability is completely stabilized, and the PIC simulation of the stable case shows the existence of cyclotron harmonics in the dispersion relation as predicted by the kinetic linear theory...
7/21/2025Non‐propagating structures and propagating waves in solar wind turbulence revealed by simulations and observationsLingling Zhao, Gary Zank, Hui LiMore InformationJournal or Juried Conf PaperPartialReviews of Modern Plasma PhysicsStructures and waves are common features of solar wind turbulence at various scales. The interplay between structures and waves is important for processes such as the turbulent energy cascade, plasma heating, and particle scattering. Our under- standing of turbulence has been advanced by not only new space missions and numerical simulations, but also techniques that have been developed to interpret the rapidly growing turbulence data. We review basic models of turbulence with a specific focus on the analysis methods for understanding magnetic structures and waves...
7/10/2025The Impact of Physical Processes on the Radial Evolution of the Distant Pickup Ion Mediated Solar WindLaxman Adhikari, Gary P. Zank, Bishwas L. Shrestha, Samira Tasnim, Lingling Zhao, Heather Elliott, Merav Opher, Bingbing Wang, Jakobus Le Roux, Alexander Pitňa, David J. McComas, Parisa Mostafavi, John Richardson, Xingyu Zhu, Yihong Wu, Justyna M. Sokół10, and Romina NikoukarMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalH+ pickup ions (PUIs), formed through charge exchange between solar wind (SW) protons and interstellar neutral hydrogen (ISN H) atoms or by the photoionization of ISN H atoms, play a key role in governing SW dynamics. These PUIs induce MHD waves by generating instabilities, driving turbulence in the outer heliosphere. The ionization cavity size is the distance at which the ISN H density becomes e−1, which is smaller in the upwind direction than in the downwind direction. Consequently, the turbulent shear source affects the SW over a larger distance in the downwind direction than in the upwind direction. Here, we integrate the continuity, momentum, and pressure equations for ISN H with the three fluid (protons, electrons, and H+ PUIs) equations and the turbulence transport equations...
6/11/2025Solar coronal heating: role of kinetic and inertial Alfvén waves in heating and charged particle accelerationSyed Ayaz, Gary P Zank , Imran A Khan , Yeimy J Rivera , Andreas Shalchi , L -L ZhaoMore InformationJournal or Juried Conf PaperPartialMonthly Notices of the Royal Astronomical SocietyA comprehensive understanding of solar coronal heating and charged particle acceleration remains one of the most critical challenges in space and astrophysical plasma physics. In this study, we explore the contribution of Alfvén waves – both in their kinetic (KAWs) and inertial (IAWs) regimes – to particle acceleration and solar coronal heating...
5/30/2025Evolution of Solar Wind Turbulence during Radial Alignment of Parker Solar Probe and Solar Orbiter in 2022 DecemberLingling Zhao, Xingyu Zhu, Luca Sorriso-Valvo, Lina Z. Hadid, Gary P. Zank, Hui Li, Samuel T. Badman, Yeimy J. Rivera, Zeping Jin, Ashok Silwal, Sujan Prasad Gautam, Monika Karki, Juan G. Alonso Guzman, Nibuna S. M. SubashchandarMore InformationJournal or Juried Conf PaperPartialThe Astrophysical Journal Supplement SeriesWe 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...
4/28/2025Development of grid-based and PINN solvers for electron kinetics in collisional non-thermal plasmasVladimir Kolobov and Lucius SchoenbaumMore InformationJournal or Juried Conf PaperPartialJournal of Physics: Conference SeriesWe compare traditional finite volume and Physics Informed Neural Network (PINN) solvers for elliptic (Poisson), hyperbolic (advection), and parabolic (diffusion) equations in 2d settings. We describe the challenges of using traditional and PINN solvers for electron kinetic equations in collisional plasmas. The advantages and drawbacks of PINNs over state-of-the-art traditional solvers are discussed...
4/20/2025Transition from Vortical to Alfvénic-like Fermi Electron AccelerationC. Crawford, H. Che, G. P. Zank, and A. O. BenzMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalUsing particle-in-cell simulations of magnetic reconnection (MR), we investigate how the changing magnetic guide field strength impacts the evolution of electron Kelvin–Helmholtz instability (EKHI) and the associated Fermi electron acceleration proposed by H. Che & G. P. Zank. Through this investigation, an Alfvénic-like Fermi electron acceleration mechanism is discovered for strong guide field MR Bg/B0 > 2.5, where Bg is the magnetic guide field...
4/18/2025Theory and observations of the interaction between magnetohydrodynamic waves and shocksLingling Zhao, Xingyu Zhu, Ashok Silwal, Gary P. Zank, Alexander PitnaMore InformationJournal or Juried Conf PaperPartialPNAS Earth, Atmospheric, and Planetary SciencesThe interaction between interplanetary shocks or planetary bow shock and upstream magnetohydrodynamics (MHD) waves (hereafter referred to as wave–shock interactions) is of fundamental importance to plasma physics. Linear waves and shocks, which are supported by MHD framework, are ubiquitous in almost all plasma environments. A thorough understanding of the interaction between linear waves and shocks is useful not only for heliophysics and astrophysics but also for other applications such as inertial confinement fusion. We revisit the theoretical problem of shock-wave interaction based on the linearized boundary conditions of MHD.
1/13/2025Plasma Optimization as a Novel Tool to Explore Plant–Microbe Interactions in Climate Smart AgricultureBinoop Mohan, Chandrima Karthik, Vinoy Thomas, Doni Thingujam, Karolina M. Pajerowska-Mukhtar, and M Shahid MukhtarMore InformationJournal or Juried Conf PaperPartialMDPI - microorganismsPlasma treatment has emerged as a promising tool for manipulating plant microbiomes and metabolites. This review explores the diverse applications and effects of plasma on these biological systems. It is hypothesized that plasma treatment will not induce substantial changes in the composition of plant microbiomes or the concentration of plant metabolites. We delve into the mechanisms by which plasma can regulate microbial communities, enhance antimicrobial activity, and recruit beneficial microbes to mitigate stress...
12/13/2024ED52B-01 Student-led Outreach Efforts from the NSF FTPP consortium (Invited)Katherine Davdison, Gary P ZankMore InformationPresentationPrimaryThe 2024 American Geophysical Union (AGU) Fall MeetingThe NSF EPSCoR Future Technologies & Enabling Plasma Processes (FTPP) is a cooperative agreement among nine Alabama universities and an in-state research corporation that focuses on plasma research with applications in agriculture, manufacturing, space science, space weather prediction, and other areas. A key mission of the FTPP consortium is to promote diversity, equity, and inclusion in all aspects of research, education, and workforce development initiatives. Graduate students are able to contribute to this mission through outreach activities...
12/9/2024ED13F-05Transforming STEM Education: NSF EPSCoR FTPP's Innovative Evaluation and Outreach StrategiesLaura Provenzani, Mehmet Sarp Yalim, Gary P Zank, Douglas Spencer, Katie HowatsonMore InformationPresentationPrimaryThe 2024 American Geophysical Union (AGU) Fall MeetingEffective evaluation techniques are crucial for advancing Earth and space science education. The NSF EPSCoR Future Technologies & Enabling Plasma Processes (FTPP), a cooperative agreement among nine Alabama universities and an in-state research corporation, focuses on plasma research with applications in agriculture, manufacturing, space science, space weather prediction, and other areas. A critical mission of our cooperative agreement is to build a foundational plasma science research and industry base supported by a skilled workforce within our state...
9/12/2024DEI and Outreach efforts from the NSF FTPP consortiumKatherine Davidson, Rebecca Harvey, Laura ProvenzaniMore InformationPresentationPrimary11th International Fermi SymposiumThe NSF Established Program to Stimulate Competitive Research (EPSCoR) Future Technologies and Enabling Plasma Processes (FTPP) is a 10-member university and industry consortium in Alabama. The project leverages Alabama's laboratory and space plasma science expertise to contribute scientific knowledge, technologies, and workforce to Alabama's aerospace, manufacturing, advanced materials, medical, bioscience, and agricultural sectors. FTPP aims to promote diversity, equity, and inclusion within Alabama's research, education, and workforce development. FTPP's diversity efforts will be highlighted, including the strategic sharing of resources between Alabama's R1 universities and HBCUs...
6/13/2024NSF EPSCoR Future Technologies & Enabling Plasma Processes (FTPP) consortium at UAH (virtual)Katherine DavdisonMore InformationPresentationPrimary2024 Workshop: DEI and Outreach in CEDARThis interactive session will focus on Diverse, Equitable, Inclusive, Outreach topics that impact and are planned or currently ongoing in the CEDAR community. Of particular interest at this year’s session is to hear from those in our community that have done/participated in, are currently doing/participating in, or are planning on doing/participating in outreach activities at their institutions or community...
2/10/2025Hybrid Simulations of Interstellar Pickup Ions at the Solar Wind Termination Shock RevisitedJoe Giacalone, M. Kornbleuth, M. Opher, M. Gkioulidou, J. Köta, E. Puzzoni, J. D. Richardson, and G. P. ZankMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalWe revisit previous hybrid simulations of the heating and acceleration of interstellar pickup ions (PUIs) at the solar wind termination shock. In previous simulations, a relatively cold initial distribution of PUIs was assumed; and while the resulting shock-heated distribution was consistent with Voyager 2 LECP measurements at about 30 keV, the intensity of the distribution downstream of the shock in the ~1–10 keV energy range was lower than predictions based on analysis of energetic neutral atoms (ENAs) from the Interstellar Boundary Explorer-Hi and Cassini's Ion and Neutral Camera.
2/4/2025A study of particle acceleration, heating, power deposition, and the damping length of kinetic Alfvén waves in non-Maxwellian coronal plasmaSyed Ayaz, G. P. Zank, I. A. Khan, G. Li and Y. J. RiveraMore InformationJournal or Juried Conf PaperPartialAstronomy & AstrophysicsContext. The heating of the solar corona and solar wind, particularly through suprathermal particles and kinetic Alfvén waves (KAWs) within the 0–10 RSun range, has been a subject of great interest for many decades. This study investigates and explores the acceleration and heating of charged particles and the role of KAWs in the solar corona.
2/1/2025PUI Heating in the Supersonic Solar WindParisa Mostafavi, Laxman Adhikari, Bishwas L. Shrestha, Gary P. Zank, Merav Opher, Matthew E. Hill, Heather A. Elliott6, Pontus C. Brandt, Ralph L. McNutt, David J. McComas, Andrew R. Poppe, Elena Provornikova, Romina Nikoukar, Peter Kollmann, S. Alan Stern, Kelsi N. Singer, Anne Verbiscer, and Joel ParkerMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalThe outer heliosphere is profoundly influenced by nonthermal energetic pickup ions (PUIs), which dominate the internal pressure of the solar wind beyond ~10 au, surpassing both solar wind and magnetic pressures. PUIs are formed mostly through charge exchange between interstellar neutral atoms and solar wind ions. This study examines the apparent heating of PUIs in the distant supersonic solar wind before reaching the heliospheric termination shock...
1/20/2025Transonic Turbulence and Density Fluctuations in the Near-Sun Solar WindL.-L. Zhao, A. Silwal, X. Zhu, H. Li, and G. P. ZankMore InformationJournal or Juried Conf PaperPartialThe Astrophysical Journal LettersWe use in situ measurements from the first 19 encounters of Parker Solar Probe and the most recent five encounters of Solar Orbiter to study the evolution of the turbulent sonic Mach number Mt (the ratio of the amplitude of velocity fluctuations to the sound speed) with radial distance and its relationship to density fluctuations. We focus on the near-Sun region with radial distances ranging from about 11 to 80 Re. Our results show that (1) the turbulent sonic Mach number Mt gradually moves toward larger values as it approaches the Sun,
1/10/2025Plasma stratification in AC discharges in noble gases at low currentsVladimir I. Kolobov and Robert R. ArslanbekovMore InformationJournal or Juried Conf PaperPartialAmerican Physical SocietyA hybrid kinetic-fluid model is used to study plasma stratification in alternating current (AC) discharges in noble gases at low plasma densities. Self-consistent coupled solutions of a nonlocal kinetic equation for electrons, a drift-diffusion equation of ions, and a Poisson equation for the electric field are obtained for a positive column and the entire discharge with near-electrode sheaths. A simplified two-level excitation-ionization model neglects the nonlinear effects due to stepwise ionization, gas heating, and Coulomb interactions among electrons...
1/10/2025Radial Evolution of MHD Turbulence Anisotropy in Low Mach Number Solar WindXingyu Zhu, Gary P. Zank, Lingling Zhao and Ashok SilwalMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalA well-known shortcoming of single-spacecraft spectral analysis is that only the 1D wavenumber spectrum can beobserved, assuming the characteristic wave propagation speed is much smaller than the solar wind flow speed. Thislimitation has motivated an extended debate about whether fluctuations observed in the solar wind are waves orstructures. Multispacecraft analysis techniques can be used to calculate the wavevector independent of theobserved frequency, thus allowing one to study the frequency–wavenumber spectrum of turbulence directly. Thedispersion relation for waves can be identified, which distinguishes them from nonpropagating structures...
11/25/2024Electrochemical Reactions at the Boundary Areas Between Cold Atmospheric Pressure Plasma, Air, and WaterJamiah Thomas and Alexander G. VolkovMore InformationJournal or Juried Conf PaperPartialPlasmaA cold atmospheric-pressure He-plasma jet (CAPPJ) interacts with air and water, producing reactive oxygen and nitrogen species (RONS), including biologically active ions, radicals, and molecules such as NOx, H2O2, HNO3, HNO2, and O3. These compounds can activate interfacial redox processes in biological tissues. The CAPPJ can oxidize N2 to HNO3 and water to H2O2 at the interface between plasma and water. It can also induce the oxidation of water-soluble redox compounds in various organisms and in vitro.
11/14/2024Alfvén waves in the solar corona: resonance velocity, damping length, and charged particles acceleration by kinetic Alfvén wavesSyed Ayaz, Gary P. Zank, Imran A. Khan, Gang Li, & Yeimy J. RiveraMore InformationJournal or Juried Conf PaperPartialNature Scientific ReportsRecent advances in heliospheric exploration spurred by NASA’s Parker Solar Probe (PSP) missionrequire a deeper understanding of the intricate dynamics of the solar corona and wind. This studyprovides a detailed examination of kinetic Alfvén waves (KAWs) within the 0 − 10 RSun range, a regiononly briefly explored in future PSP passages. Employing the framework of kinetic plasma theory andincorporating a non-thermal Cairns velocity distribution, we investigate the impact of the non-thermalindex parameter Λ on the resultant resonance velocity vres...
10/1/2024Metis Observation of the Onset of Fully Developed Turbulence in the Solar CoronaDaniele Telloni, Luca Sorriso-Valvo , Gary P. Zank, Marco Velli, Vincenzo Andretta, Denise Perrone, Raffaele Marino, Francesco Carbone, Antonio Vecchio, Laxman Adhikari, Lingling Zhao, Sabrina Guastavino, Fabiana Camattari, Chen Shi, Nikos Sioulas, Zesen Huang, Marco Romoli, Ester Antonucci, Vania Da Deppo, Silvano Fineschi, Catia Grimani, Petr Heinzel, John D. Moses, Giampiero Naletto, Gianalfredo Nicolini, Daniele Spadaro, Marco Stangalini, Luca Teriaca, Michela Uslenghi, Lucia Abbo, Frédéric Auchère, Regina Aznar Cuadrado, Arkadiusz Berlicki,Roberto Bruno, Aleksandr Burtovoi, Gerardo Capobianco, Chiara Casini, Marta Casti, Paolo Chioetto, Alain J. Corso, Raffaella D’Amicis, Yara De Leo, Michele Fabi, Federica Frassati, Fabio Frassetto, Silvio Giordano, Salvo L. Guglielmino, Giovanna Jerse, Federico Landini, Alessandro Liberatore, Enrico Magli, Giuseppe Massone, Giuseppe Nisticò, Maurizio Pancrazzi, Maria G. Pelizzo, Hardi Peter, Christina Plainaki , Luca Poletto, Fabio Reale, Paolo Romano, Giuliana Russano, Clementina Sasso, Udo Schühle, Sami K. Solanki, Leonard Strachan, Thomas Straus, Roberto Susino, Rita Ventura, Cosimo A. Volpicelli, Joachim Woch, Luca Zangrilli, Gaetano Zimbardo, and Paola ZuppellaMore InformationJournal or Juried Conf PaperPartialThe Astrophysical Journal LettersThis Letter reports the first observation of the onset of fully developed turbulence in the solar corona. Long timeseries of white-light coronal images, acquired by Metis aboard Solar Orbiter at 2 minutes cadence and spanningabout 10 hr, were studied to gain insight into the statistical properties of fluctuations in the density of the coronalplasma in the time domain. From pixel-by-pixel spectral frequency analysis in the whole Metis field of view, thescaling exponents of plasma fluctuations were derived...
9/20/2024A Data-constrained Analysis for Joule Heating as a Solar Active Region Atmosphere Heating Mechanism. I. Sunspot Umbral Light BridgeM. S. Yalim, M. Frisse, C. Beck, D. P. Choudhary, A. Prasad, S. S. Nayak, and G. P. ZankMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalUnderstanding the mechanisms underlying the heating of the solar atmosphere is a fundamental problem in solar physics. The lower atmosphere of the Sun (i.e., photosphere and chromosphere) is composed of weakly ionized plasma. This results in anisotropic dissipation of electric currents by Coulomb and Cowling resistivities.
9/20/2024Turbulence, Waves, and Taylor’s Hypothesis for Heliosheath ObservationsL.-L. Zhao, G. P. Zank, M. Opher, B. Zieger, H. Li, V. Florinski, L. Adhikari, X. Zhu, and M. NakanotaniMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalMagnetic field fluctuations measured in the heliosheath by the Voyager spacecraft are often characterized as compressible, as indicated by a strong fluctuating component parallel to the mean magnetic field. However, the interpretation of the turbulence data faces the caveat that the standard Taylor's hypothesis is invalid because the solar wind flow velocity in the heliosheath becomes subsonic and slower than the fast magnetosonic speed, given the contributions from hot pickup ions (PUIs) in the heliosheath...
9/11/2024Influence of alkanolamine plasmas on poly(ethylene terephthalate) fibrous biomaterial constructBernabe S Tucker, Gerardo Hernández Moreno, Patrick T.J. Hwang, Ho-Wook Jun, Vinoy ThomasMore InformationJournal or Juried Conf PaperPartialAsian Chemical Editorial SocietyThe development of fibrous polymer scaffolds is highly valuable for applications in tissue engineering. Furthermore, there is an extensive body of literature for chemical methods to produce scaffolds that release nitric oxide. However, these methods often use harsh chemistries and leave behind bulk waste...
9/10/2024Multispecies Energetic Particle Acceleration Associated with CIR and ICME-driven ShocksLingling Zhao, Gary P. Zank, Bingbing Wang, Alexander Pitña, Byeongseon Park, Masaru Nakanotani, and Xingyu ZhuMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalA multispecies energetic particle intensity enhancement event at 1 au is analyzed. We identify this event as a corotating interaction region (CIR) structure that includes a stream interface (SI), a forward-reverse shock pair, and an embedded heliospheric current sheet (HCS). The distinct feature of this CIR event is that (1) the high-energy (>1 MeV) ions show significant flux enhancement at the reverse wave (RW)/shock of the CIR structure, following their passage through the SI and HCS. The flux amplification appears to depend on the energy per nucleon. (2) Electrons in the energy range of 40.5–520 keV are accelerated immediately after passing through the SI and HCS regions, and the flux quickly reaches a peak for low-energy electrons...
8/16/2024Plasma/Ozone Induced PolyNaSS Graft-Polymerization onto PEEK Biomaterial for Bio-integrated Orthopedic ImplantsChandrima Karthik, Renjith Rajan Pillai, Gerardo Hernandez Moreno, Prabaha Sikder, Namasivayam Ambalavanan & Vinoy ThomasMore InformationJournal or Juried Conf PaperPartialThe Journal of The Minerals, Metals & Materials Society (TMS)Owing to its superior bulk mechanical properties, poly (ether ether ketone) (PEEK) has gained popularity over the past 15 years as a metal substitute in biomedical implants. Low surface energy is a fundamental issue with PEEK implants. This low surface energy caused by a moderately hydrophobic surface may be able to inhibit cellular adherence and result in the development of an inflammatory response, which may result in cell necrosis and apoptosis...
7/1/2024Novel superhard BC10N synthesized by microwave plasma CVDKallol Chakrabarty, Paul A. Baker, Shane A. CatledgeMore InformationJournal or Juried Conf PaperPartialScienceDirect Diamond & Related MaterialsMicrowave Plasma Chemical Vapor Deposition (MPCVD) was used to synthesize novel superhard BC10N on silicon substrates. Feedgas mixtures of H2, CH4, N2, and B2H6 were used for a range of systematically varied microwave power, chamber pressure, and flow rate conditions. Optical Emission Spectroscopy (OES) was used to guide the synthesis of BC10N. Plasma optical emission from the C2 peak increases with pressure up to 80 Torr and saturates in the 80–100 Torr range...
6/10/2024Solar Cycle Dependence of the Turbulence Cascade Rate at 1 auSujan Prasad Gautam, Laxman Adhikari, Gary P Zank, Ashok Silwal, and Lingling ZhaoMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalWe study the solar cycle dependence of various turbulence cascade rates based on the methodology developed byAdhikari et al. that utilizes Kolmogorov phenomenology. This approach is extended to derive the heating rates foran Iroshnikov–Kriachnan (IK) phenomenology...
5/17/2024A plasma-3D print combined in vitro platform with implications for reliable materiobiological screeningGerardo Hernandez-Moreno, Vineeth M. Vijayan, Brian A. Halloran, Namasivayam Ambalavanan, Alexandria L. Hernandez-Nichols, John P. Bradford, Renjith R. Pillai and Vinoy ThomasMore InformationJournal or Juried Conf PaperPartialJournal of Materials Chemistry BMateriobiology is an emerging field focused on the physiochemical properties of biomaterials concerning biological outcomes which includes but is not limited to the biological responses and bioactivity of surface-modified biomaterials. Herein, we report a novel in vitro characterization platform for characterizing nanoparticle surface-modified 3D printed PLA scaffolds. We have introduced innovative design parameters that were practical for ubiquitous in vitro assays like those utilizing 96 and 24-well plates...
5/1/2024Characterization of Turbulent Fluctuations in the Sub-Alfvénic Solar WindG. P. Zank, L.-L. Zhao, L. Adhikari, D. Telloni, Prashant Baruwal, Prashrit Baruwal, Xingyu Zhu, M. Nakanotani1 , A. Pitňa, J. C. Kasper, and S. D. BaleMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalParker Solar Probe (PSP) observed sub-Alfvénic solar wind intervals during encounters 8–14, and low-frequency magnetohydrodynamic (MHD) turbulence in these regions may differ from that in super-Alfvénic wind. We apply a new mode decomposition analysis to the sub-Alfvénic flow observed by PSP on 2021 April 28, identifying and characterizing entropy, magnetic islands, forward and backward Alfvén waves, including weakly/nonpropagating Alfvén vortices, forward and backward fast and slow magnetosonic (MS) modes.
5/1/2024Turbulence, and Proton and Electron Heating Rates in the Solar Corona: Analytical ApproachLaxman Adhikari, Gary P. Zank, Daniele Telloni, Lingling Zhao, Bingbing Wang, Gary Webb, Bofeng Tang, and Katariina NykyriMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalAnalytical solutions for 2D and slab turbulence energies in the solar corona are presented, including a derivation of the corresponding correlation lengths, with implications for the proton and electron temperatures in the solar corona. These solutions are derived by solving the transport equations for 2D and slab turbulence energies and their correlation lengths, as well as proton and electron pressures...
4/10/2024MHD Inertial and Energy-containing Range Turbulence Anisotropy in the Young Solar WindLaxman Adhikari, Gary P. Zank, Lingling Zhao, Bingbing Wang, Bofeng Tang, Daniele Telloni, Alexander Pitna, and Katariina NykyriMore InformationJournal or Juried Conf PaperPartialThe Astrophisical JournalWe study solar wind turbulence anisotropy in the inertial and energy-containing ranges in the inbound and outbound directions during encounters 1–9 by the Parker Solar Probe (PSP) for distances between ∼21 and 65 Re. Using the Adhikari et al. approach, we derive theoretical equations to calculate the ratio between the 2D and slab fluctuating magnetic energy, fluctuating kinetic energy, and the outward/inward Elsässer energy in the inertial range...
4/8/2024Upcycling of Waste Polymer Using Surface Modified Hemp Derived Biochar Carbon for Sustainable Packaging ApplicationsGautam Chandrasekhar, Kearston Edwards, Desmond Mortley, and Vijaya RangariMore InformationJournal or Juried Conf PaperPartialACS PublicationsOut of 300 million tons of plastics produced globally, only 10% are being recycled. Due to this, there is always a demand for alternative, effective methods to cope with this low recycling rate of plastics. This work demonstrates such an effective technique for recycling high-density polyethylene (HDPE) wastes, incorporating biochar synthesized from postharvest hemp crop residue as fillers. Generally, carbon-based materials are considered to have inert surface properties...
4/1/2024Suprathermal Electron Transport in the Solar Wind: Effects of Coulomb Collisions and Whistler TurbulenceBofeng Tang, Laxman Adhikari, Gary P. Zank, and HaihongMore InformationJournal or Juried Conf PaperPartialThe Astrophisical JournalThe nature and radial evolution of solar wind electrons in the suprathermal energy range are studied. A wave–particle interaction tensor and a Fokker–Planck Coulomb collision operator are introduced into the kinetic transport equation describing electron collisions and resonant interactions with whistler waves. The diffusion tensor includes diagonal and off-diagonal terms, and the Coulomb collision operator applies to arbitrary electron velocities describing collisions with both background protons and electrons...
2/28/2024Effect on thermal, mechanical, and biodegradable properties of plasma-treated fish scale powder/linear low-density polyethylene polymer composite filmsMatthew Bonzu Ackah, Radhika Panickar, Vijaya K. RangariMore InformationJournal or Juried Conf PaperPartialJournal of Applied Polymer ScienceIn the present work, we report the effect of low-temperature plasma treatment on thermal, mechanical, and biodegradable properties of polymer composite blown films prepared from carp fish scale powder (CFSP) and linear low-density polyethylene (LLDPE). The CFSP was melt compounded with LLDPE using a filament extruder to prepare 1, 2, and 3 wt.% of CFSP in LLDPE polymer composite filaments. These filaments were further pelletized and extruded into blown films. The blown films extruded with 1, 2, and 3 wt.% of CFSP in LLDPE were tested for thermal and mechanical properties...
2/10/2024Effects of Nonzero-frequency Fluctuations on Turbulence Spectral ObservationsL.-L. Zhao, G. P. Zank, and H. LiMore InformationJournal or Juried Conf PaperPartialThe Astrophysical Journal LettersIn situ observations of turbulence spectra in space plasmas are usually interpreted as wavenumber spectra, assuming that the fluctuation frequency is negligible in the plasma flow frame. We explore the effects of nonzero frequency in the plasma flow frame on turbulence spectral observations. The finite frequency can be caused by either propagating waves or nonlinear broadening of nonpropagating structures...
12/10/2023A Comparison of Particle-in-cell and Hybrid Simulations of the Heliospheric Termination ShockM. Swisdak, J. Giacalone, J. F. Drake, M. Opher, G. P. Zank, and B. ZiegerMore InformationJournal or Juried Conf PaperPartialThe Astrophisical JournalWe compare hybrid (kinetic proton, fluid electron) and particle-in-cell (kinetic proton, kinetic electron) simulationsof the solar wind termination shock with parameters similar to those observed by Voyager 2 during its crossing.The steady-state results show excellent agreement between the downstream variations in the density, plasmavelocity, and magnetic field...
12/7/2023Physics and applications of dusty plasmas: The Perspectives 2023J. Beckers, J. Berndt, D. Block, M. Bonitz, P. J. Bruggeman, L. Couëdel, G. L. Delzanno, Y. Feng, Edward Thomas, et al.More InformationJournal or Juried Conf PaperPartialAIP PublishingDusty plasmas are electrically quasi-neutral media that, along with electrons, ions, neutral gas, radiation, and electric and/or magnetic fields, also contain solid or liquid particles with sizes ranging from a few nanometers to a few micrometers. These media can be found in many natural environments as well as in various laboratory setups and industrial applications. As a separate branch of plasma physics, the field of dusty plasma physics was born in the beginning of 1990s at the intersection of the interests of the communities investigating astrophysical and technological plasmas...
12/1/2023The temporal and latitudinal dependences of turbulence driven by pickup ions in the outer heliosphereBingbing Wang, Lingling Zhao, Paria Abouhamzeh, Gary P. Zank, Laxman AdhikariMore InformationJournal or Juried Conf PaperPartialFrontiers in Astronomy and Space SciencesThe distribution of turbulence in the heliosphere remains a mystery, due to the complexity in not only modeling the turbulence transport equations but also identifying the drivers of turbulence that vary with time and spatial location. Beyond the ionization cavity (a few astronomical units (AU) from the Sun), the turbulence is driven predominantly by freshly created pickup ions (PUIs), in contrast to the driving by stream shear and compression...
12/1/2023Acceleration and Spectral Redistribution of Cosmic Rays in Radio-jet Shear FlowsG. M. Webb, Y. Xu, P. L. Biermann, S. Al-Nussirat, P. Mostafavi, G. Li, A. F. Barghouty, and G. P. ZankMore InformationJournal or Juried Conf PaperPartialThe Astrophisical JournalA steady-state, semi-analytical model of energetic particle acceleration in radio-jet shear flows due to cosmic-rayviscosity obtained by Webb et al. is generalized to take into account more general cosmic-ray boundary spectra.This involves solving a mixed Dirichlet–Von Neumann boundary value problem at the edge of the jet...
11/27/2023Machine learning the relationship between Debye temperature and superconducting transition temperatureAdam D. Smith, Sumner B. Harris, Renato P. Camata, Da Yan, and Cheng-Chien ChenMore InformationJournal or Juried Conf PaperPartialAmerican Physical SocietyIn order to verify this bound, we train machine learning (ML) models with 10 330 samples in the Materials Project database to predict ΘD. By applying our ML models to 9860 known superconductors in the NIMS SuperCon database, we find that the conventional superconductors in the database indeed follow the proposed bound.
10/12/2023Understanding the Formation of Stable and Unstable Cathode Spots in Plasma-Liquid InteractionsBhagirath Ghimire, Vladimir I Kolobov, Gabe XuMore InformationPresentationPartial76th Annual Gaseous Electronics ConferenceInteractions of plasmas with liquid cathode electrodes have gained significant attention in recent years due to their potential applications in various fields, including environmental remediation, biomedicine, and materials synthesis. Cathode spots, localized regions of intense plasma discharge near the cathode surface, play a crucial role in these interactions. Herein, we have investigated the formation of stable and unstable cathode spots on the surface of liquid cathode...
9/28/2023Particle-in-cell simulations – ion beam instabilities and the generation of Alfvén and whistler waves in low β plasmaH. Che, A. O. Benz, and G. P. ZankMore InformationJournal or Juried Conf PaperPartialMonthly Notices of the Royal Astronomical SocietyIon beam-driven instabilities in a collisionless space plasma with low β, i.e. low plasma and magnetic pressure ratio, are investigated using particle-in-cell (PIC) simulations. Specifically, the effects of different ion drift velocities on the development of Buneman and resonant electromagnetic (EM) right-handed (RH) ion beam instabilities are studied. Our simulations reveal that both instabilities can be driven when the ion beam drift exceeds the theoretical thresholds...
9/10/2023Energy Budget in the Solar CoronaDaniele Telloni, Marco Romoli, Marco Velli, Gary P. Zank, Laxman Adhikari, Lingling Zhao, Cooper Downs, Jasper S. Halekas, Jaye L. Verniero, Michael D. McManus, Chen Shi, Aleksandr Burtovoi, Roberto Susino, Daniele Spadaro, Alessandro Liberatore, Ester Antonucci, Yara De Leo, Lucia Abbo, Federica Frassati, Giovanna Jerse, Federico Landini, Gianalfredo Nicolini, Maurizio Pancrazzi, Giuliana Russano, Clementina Sasso, Vincenzo Andretta, Vania Da Deppo, Silvano Fineschi, Catia Grimani, Petr Heinzel, John D. Moses, Giampiero Naletto, Marco Stangalini, Luca Teriaca, Michela Uslenghi, Stuart D. Bale, and Justin C. KasperMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalThis paper addresses the first direct investigation of the energy budget in the solar corona. Exploiting jointobservations of the same coronal plasma by Parker Solar Probe and the Metis coronagraph aboard Solar Orbiterand the conserved equations for mass, magnetic flux, and wave action, we estimate the values of all termscomprising the total energy flux of the proton component of the slow solar wind from 6.3 to 13.3 Re. For distancesfrom the Sun to less than 7 Re, we find that the primary source of solar wind energy is magnetic fluctuationsincluding Alfvén waves...
8/29/2023Electron kinetics in a positive column of AC discharges in a dynamic regimeNathan A Humphrey and Vladimir I KolobovMore InformationJournal or Juried Conf PaperPartialIOP ScienceWe have performed hybrid kinetic-fluid simulations of a positive column in alternating current (AC) argon discharges over a range of driving frequencies f and gas pressure p for the conditions when the spatial nonlocality of the electron energy distribution function (EEDF) is substantial. Our simulations confirmed that the most efficient conditions of plasma maintenance are observed in the dynamic regime when time modulations of mean electron energy (temperature) are substantial...
8/28/2023Linear Mode Decomposition in Magnetohydrodynamics RevisitedG. P. Zank, L.-L. Zhao, L. Adhikari, M. Nakanotani, A. Pitňa, D. Telloni, and H. CheMore InformationJournal or Juried Conf PaperPartialThe Astrophysical Journal Supplement SeriesSmall-amplitude fluctuations in the magnetized solar wind are measured typically by a single spacecraft. In the magnetohydrodynamics (MHD) description, fluctuations are typically expressed in terms of the fundamental modes admitted by the system. An important question is how to resolve an observed set of fluctuations, typically plasma moments such as the density, velocity, pressure, and magnetic field fluctuations, into their constituent fundamental MHD modal components. Despite its importance in understanding the basic elements of waves and turbulence in the solar wind, this problem has not yet been fully resolved...
8/19/2023Formation of turing patterns in strongly magnetized electric dischargesMohamad Menati, Stephen Williams, Behnam Rasoolian, Edward Thomas Jr. & Uwe KonopkaMore InformationJournal or Juried Conf PaperPartialNature Communications PhysicsPattern formation and self-organization in many biological and non-biological systems can be explained through Turing’s activator-inhibitor model. Here we show how this model can be employed to describe the formation of filamentary structures in a low-pressure electric discharge exposed to a strong magnetic field. Theoretical investigation reveals that the fluid equations describing a magnetized plasma can be rearranged to take the mathematical form of Turing’s activator-inhibitor model...
8/10/2023Theory and Transport of Nearly Incompressible Magnetohydrodynamic Turbulence: High Plasma Beta RegimeLaxman Adhikari, Gary P. Zank, Bingbing Wang, Lingling Zhao, Daniele Telloni, Alex Pitna, Merav Opher, Bishwas Shrestha, David J. McComas, and Katariina NykyriMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalNearly incompressible magnetohydrodynamic (NI MHD) theory for β ∼ 1 (or β = 1) plasma has been developedand applied to the study of solar wind turbulence. The leading-order term in β ∼ 1 or β = 1 plasma describes themajority of 2D turbulence, while the higher-order term describes the minority of slab turbulence. Here, we developnew NI MHD turbulence transport model equations in the high plasma beta regime...
8/1/2023Dusty PlasmasEdward ThomasMore InformationJournal or Juried Conf PaperPartialNuclear & Plasma Sciences SocietyPlasmas are a universal phenomenon. They are ionized gases, formed from a collection of electrons (negatively charged), ions (positively, and sometimes negatively, charged), and neutral atoms that can freely interact with each other. From the solar wind in space to bolts of lightning on Earth, plasmas can be found nearly everywhere.
7/30/2023Space Plasma Physics: A ReviewBruce T. Tsurutani, Gary P. Zank, Veerle J. Sterken, Kazunari Shibata, Tsugunobu Nagai, Anthony J. Mannucci, David M. Malaspina, Gurbax S. Lakhina, Shrikanth G. Kanekal, Keisuke Hosokawa, Richard B. Horne, Rajkumar Hajra, Karl-Heinz Glassmeier, C. Trevor Gaunt, Peng-Fei Chen, and Syun-Ichi AkasofuMore InformationJournal or Juried Conf PaperPartialIEEE Transactions on Plasma ScienceOwing to the ever-present solar wind, our vast solar system is full of plasmas. The turbulent solar wind, together with sporadic solar eruptions, introduces various space plasma processes and phenomena in the solar atmosphere all the way to Earth’s ionosphere and atmosphere and outward to interact with the interstellar media to form the heliopause and termination shock. Remarkable progress has been made in space plasma physics in the last 65 years, mainly due to sophisticated in situ measurements of plasmas, plasma waves, neutral particles, energetic particles, and dust via space-borne satellite instrumentation...
7/27/2023Influence of Liquid Conductance on the Temporal Evolution of Self-Organization Patterns in Atmospheric Pressure DC Glow DischargesBhagirath Ghimire, Vladimir Kolobov, and Kunning Gabriel XuMore InformationJournal or Juried Conf PaperPartialIOP PublishingSelf-Organized Patterns (SOPs) at plasma-liquid interface in atmospheric pressure plasma discharges refer to the formation of intricate and puzzling structures due to the interplay of electrodynamic and hydrodynamic processes. Studies conducted to date have shown that this phenomenon results in the formation of distinctive patterns such as circular ring, star, gear, dots, spikes, etc., and primarily depends on working gas, electrolyte type, gap distance, current, conductivity, etc. However, an adequate understanding of how these patterns change from one type to another is still not available...
7/23/2023Impact of Magnetic Focusing on the Transport of Energetic Electrons in the Solar CoronaBofeng Tang, Haihong Che, Gary P. ZankMore InformationPresentationPartial20th Annual International Astrophysics ConferenceObservations of Type III radio bursts discovered that electron beams with power-law energy spectra are commonly produced during solar flares. The locations of these electron beams are ∼ 300 Mm above the particle acceleration region of the photosphere, and the velocities range from 3 to 10 times the local background electron thermal velocity. However, the mechanism that can commonly produce electron beams during the propagation of energetic electrons with power-law energy spectra in the corona remains unclear...
7/23/2023Understanding the heating mechanism of the solar active region atmosphere in chromosphereMehmet Sarp Yalim, Gary Zank, Christian Beck, Debi Prasad Choudhary, Avijeet Prasad, Qiang Hu, and Makayla FrisseMore InformationPresentationPartial20th Annual International Astrophysics ConferenceUnderstanding the mechanisms underlying the heating of the solar atmosphere is a fundamental problem in solar physics. In this paper, we present an overview of our research on understanding the heating mechanism of the solar active region atmosphere in chromosphere. We investigate Joule heating due to the dissipation of currents perpendicular to the magnetic field by the Cowling resistivity using a data-constrained analysis based on observational and tabulated theoretical/semi-empirical solar atmosphere model data...
7/23/2023Transmission of magnetic island modes across interplanetary shocks: comparison of theory and observationsA Pitna, G P Zank, M Nakanotani, L-L Zhao, L Adhikari, J Safrankova, and Z NemecekMore InformationPresentationPartial20th Annual International Astrophysics ConferenceInterplanetary shock waves are observed frequently in turbulent solar wind. They naturally enhance the temperature/entropy of the plasma through which they propagate. Moreover, many studies have shown that they also act as an amplifier of the fluctuations incident on the shock front. Solar wind turbulent fluctuations can be well described as the superposition of quasi-2D and slab components, the former being energetically dominant. In this paper, we address the interaction of fast forward shocks observed by the Wind spacecraft at 1 AU and quasi-2D turbulent fluctuations in the framework of the Zank et al. (2021) transmission model...
7/3/2023Structure prediction and materials design with generative neural networksDa Yan, Adam D. Smith, & Cheng-Chien ChenMore InformationPartialPartialNature Computational ScienceThe prediction of stable crystal structures is an important part of designing solid-state crystalline materials with desired properties. Recent advances in structural feature representations and generative neural networks promise the ability to efficiently create new stable structures to use for inverse design and to search for materials with tailored functionalities.
6/16/2023Electromagnetic electron Kelvin–Helmholtz instabilityHaihong Che, Gary P. ZankMore InformationJournal or Juried Conf PaperPartialAIP PublishingOn electron kinetic scales, ions and electrons decouple, and electron velocity shear on electron inertial length de can trigger electromagnetic (EM) electron Kelvin–Helmholtz instability (EKHI). In this paper, we present an analytic study of EM EKHI in an inviscid collisionless plasma with a step-function electron shear flow...
6/15/2023Solar wind with Hydrogen Ion charge Exchange and Large-Scale Dynamics (SHIELD) DRIVE Science CenterMerav Opher, John Richardson, Gary Zank, Vladimir Florinski, Joe Giacalone, Justyna M. Sokół, Gabor Toth, Sanlyn Buxner, Marc Kornbleuth, Matina Gkioulidou, Romina Nikoukar, Bart Van der Holst, Drew Turner, Nicholas Gross, James Drake, Marc Swisdak, Kostas Dialynas, Maher Dayeh, Yuxi Chen, Bertalan Zieger, Erick Powell, Chika Onubogu, Xiaohan Ma, Ethan Bair, Heather Elliott, Andre Galli, Lingling Zhao, Laxman Adhikari, Masaru Nakanotani, Matthew E. Hill, Parisa Mostafavi, Senbei Du, Fan Guo, Daniel Reisenfeld, Stephen Fuselier, Vladislav Izmodenov, Igor Baliukin, Alan Cummings, Jesse Miller, Bingbing Wang, Keyvan Ghanbari, Jozsef Kota, Abraham Loeb, Juditra Burgess, Sarah Chobot Hokanson , Cherilyn Morrow, Adam Hong, Andrea BoldonMore InformationJournal or Juried Conf PaperPartialFrontiers in Astronomy and Space SciencesMost stars generate winds and move through the interstellar medium that surrounds them. This movement creates a cocoon formed by the deflection of these winds that envelops and protects the stars. We call these “cocoons” astrospheres. The Sun has its own cocoon, the heliosphere. The heliosphere is an immense shield that protects the Solar System from harsh, galactic radiation. The radiation that enters the heliosphere affects life on Earth as well as human space exploration. Galactic cosmic rays are the dominant source of radiation and principal hazard affecting space missions within our Solar System. ..
6/6/2023Diversity in the space physics community: an overview of collaborative efforts led by The University of Alabama in HuntsvilleMehmet S. Yalim, Gary P. Zank, Laura Provenzani, Douglas Spencer, Katie HowatsonMore InformationJournal or Juried Conf PaperPartialFrontiers in Astronomy and Space SciencesThe field of Space Physics has significant recruitment potential. Almost everyone has been fascinated by space in one way or another since their early childhood. From this perspective, Space Physics might be expected to exhibit considerable diversity as a discipline. Regrettably, as in many STEM fields, the reality is quite different. Numerous reasons have been advanced about why the reality and the expectation diverge but one observation we have made over the years stands out, and, that is, that when students are given the opportunity, they are very eager to learn about Space Physics and enthusiastic about working on space physics projects. At The University of Alabama in Huntsville, we have developed a series of outreach programs, including summer programs, that are aimed at bringing students not typically exposed to space physics into the Space Physics community through working on real research projects that have the potential to produce journal publication results...
3/1/2023Probing the Length of the Heliospheric Tail with Energetic Neutral Atoms (ENAs) from 0.52 to 80 keVM. Kornbleuth, M. Opher, K. Dialynas, G. P. Zank, B. B. Wang, I. Baliukin, M. Gkioulidou, J. Giacalone, V. Izmodenov, J. M. Sokół, M. A. DayehMore InformationJournal or Juried Conf PaperPartialThe Astrophysical Journal LettersThe shape of the heliosphere is currently under active debate. Energetic neutral atoms (ENAs) offer the bestmethod for investigating the global structure of the heliosphere. To date, the Interstellar Boundary Explorer (IBEX)and the Ion and Neutral Camera (INCA) that was on board Cassini provide the only global ENA observations ofthe heliosphere. While extensive modeling has been done at IBEX-Hi energies (0.52–6 keV), no global ENAmodeling has been conducted for INCA energies (5.2–55 keV). Here, we use an ENA model of the heliospherebased on hybrid results that capture the heating and acceleration of pickup ions (PUIs) at the termination shock tocompare modeled global ENA results with IBEX-Hi and INCA observations using both a long- and short-tailmodel of the heliosphere...
3/1/2023Science-based strategies of antibacterial coatings with bactericidal properties for biomedical and healthcare settingsRakesh Pemmada, Aishwarya Shrivastava, Madhusmita Dash, Kuiyan Cui, Prasoon Kumar, Seeram Ramakrishna, Yubin Zhou, Vinoy Thomas, Himansu Sekhar NandaMore InformationJournal or Juried Conf PaperPartialCurrent Opinion in Biomedical EngineeringContamination transmission in biomedical and healthcare settings is a significant challenge due to inadequate microbiological protection from anti-infection agents and disinfectants. Antimicrobial surfaces have been used as a current hygiene method to combat the growing microbes. Interestingly, several approaches have been developed to block biofilm formation by integrating the biocidal agents. Currently, the primary focus is on creating a contact-killing surface or a surface that may reduce the microbial load to a level below threshold. This review focuses on introduction of antimicrobials into the surfaces through various science-based strategies for reducing the bacterial contamination within different medical services environment...
2/27/2023A hybrid kinetic-continuum computational model for simulations of laser-induced plasma plumesAlexey N. Volkov, Michael A. Stokes, Zhibin Lin, Saad A. Khairallah, Alexander M. RubenchikPresentationPartialSIAM Conference on Computational Science and Engineering (CSE23)NA
2/20/2023An Anomalous Cosmic-Ray Mediated Termination Shock: Implications for Energetic Neutral AtomsM. Kornbleuth, M. Opher, G. P. Zank, B. B. Wang, J. Giacalone, M. Gkioulidou, K. DialynasMore InformationJournal or Juried Conf PaperPartialThe Astrophysical Journal LettersThe Voyager 2 crossing of the termination shock indicated that most of the upstream energy from the thermal solarwind ions was transferred to pickup ions (PUIs) and other energetic particles downstream of the shock. We usehybrid simulations at the termination shock for the Voyager 2, flank, and tail directions to evaluate the distributionsof different ion species downstream of the shock over the energy range of 0.52–55 keV. Here, we extend the workof Gkioulidou et al., which showed an energy-dependent discrepancy between modeled and energetic neutral atom(ENA) observations, and fit distributions to a hybrid model to show that a population of PUIs accelerated viadiffusive shock acceleration (DSA) to become low-energy anomalous cosmic rays (ACRs) can bridge the gapbetween modeled and observed ENA fluxes...
2/20/2023Coronal Loop Heating by Nearly Incompressible Magnetohydrodynamic and Reduced Magnetohydrodynamic Turbulence ModelsM. S. Yalim, G. P. Zank, M. Asgari-TarghiMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalThe transport of waves and turbulence beyond the photosphere is central to the coronal heating problem.Turbulence in the quiet solar corona has been modeled on the basis of the nearly incompressiblemagnetohydrodynamic (NI MHD) theory to describe the transport of low-frequency turbulence in openmagnetic field regions. It describes the evolution of the coupled majority quasi-2D and minority slab component,driven by the magnetic carpet and advected by a subsonic, sub-Alfvénic flow from the lower corona. In this paper,we couple the NI MHD turbulence transport model with an MHD model of the solar corona to study the heatingproblem in a coronal loop...
2/20/2023Does Turbulence along the Coronal Current Sheet Drive Ion Cyclotron Waves?Daniele Telloni, Gary P. Zank, Laxman Adhikari, Lingling Zhao, Roberto Susino, Ester Antonucci, Silvano Fineschi, Marco Stangalini, Catia Grimani, Luca Sorriso-Valvo, Daniel Verscharen, Raffaele Marino, Silvio Giordano, Raffaella D’Amicis, Denise Perrone, Francesco Carbone,Alessandro Liberatore, Roberto Bruno, Gaetano Zimbardo, Marco Romoli, Vincenzo Andretta, Vania Da Deppo, Petr Heinzel, John D. Moses, Giampiero Naletto, Gianalfredo Nicolini, Daniele Spadaro, Luca Teriaca, Aleksandr Burtovoi, Yara De Leo, Giovanna Jerse, Federico Landini,Maurizio Pancrazzi, Clementina Sasso, Alessandra SlemerMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalEvidence for the presence of ion cyclotron waves (ICWs), driven by turbulence, at the boundaries of the currentsheet is reported in this paper. By exploiting the full potential of the joint observations performed by Parker SolarProbe and the Metis coronagraph on board Solar Orbiter, local measurements of the solar wind can be linked withthe large-scale structures of the solar corona. The results suggest that the dynamics of the current sheet layersgenerates turbulence, which in turn creates a sufficiently strong temperature anisotropy to make the solar-windplasma unstable to anisotropy-driven instabilities such as the Alfvén ion cyclotron, mirror-mode, and firehoseinstabilities...
2/20/2023Relating Energetic Ion Spectra to Energetic Neutral AtomsBingbing Wang, Gary P. Zank, Bishwas L. Shrestha, Marc Kornbleuth, and Merav OpherMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalHeliospheric energetic neutral atoms (ENAs) originate from energetic ions that are neutralized by charge exchangewith neutral atoms in the heliosheath and very local interstellar medium (VLISM). Since neutral atoms areunaffected by electromagnetic fields, they propagate ballistically with the same speeds as parent particles.Consequently, measurements of ENA distributions allow one to remotely image the energetic ion distributions inthe heliosheath and VLISM. The origin of the energetic ions that spawn ENAs is still debated, particularly atenergies higher than ∼keV. In this work, we summarize five possible sources of energetic ions in the heliosheaththat cover the ENA energy from a few keV to hundreds of keV...
2/10/2023Observations of Waves and Structures by Frequency–Wavenumber Spectrum in Solar Wind TurbulenceL.-L. Zhao, G. P. Zank, M. Nakanotani, L. AdhikariMore InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalA well-known shortcoming of single-spacecraft spectral analysis is that only the 1D wavenumber spectrum can beobserved, assuming the characteristic wave propagation speed is much smaller than the solar wind flow speed. Thislimitation has motivated an extended debate about whether fluctuations observed in the solar wind are waves orstructures. Multispacecraft analysis techniques can be used to calculate the wavevector independent of theobserved frequency, thus allowing one to study the frequency–wavenumber spectrum of turbulence directly...
12/21/2022Ionization waves in low-current dc discharges in noble gases obtainedwith a hybrid kinetic-fluid modelVladimir I. Kolobov and Robert R. ArslanbekovMore InformationJournal or Juried Conf PaperPartialPHYSICAL REVIEW E 106, 065206 (2022)A hybrid kinetic-fluid model is used to study ionization waves (striations) in a low-current plasma column of dc discharges in noble gases. Coupled solutions of a kinetic equation for electrons, a drift-diffusion equation for ions, and a Poisson equation for the electric field are obtained to clarify the nature of plasma stratification in the positive column. A simplified two-level excitation-ionization model is used for the conditions when the nonlinear effects due to stepwise ionization, gas heating, and Coulomb interactions among electrons are negligible. It is confirmed that the nonlocal effects are responsible for the formation of moving striations in dc discharges at low plasma densities and low values of pR (the product of gas pressure and tube radius)...
12/15/2022Cusp ion precipitation associated with magnetopause reconnection viewed from global hybrid simulationsYu Lin, Xueyi Wang, Mark L. Adrian et alMore InformationPresentationPartialAGU Fall 2022 Meeting in Chicago, IllinoisWe investigate the linkage between magnetic reconnection at the magnetopause and cusp ion injections in the ionosphere by conducting 3D global hybrid simulations using ANGIE3D. The simulation is performed with an interplanetary magnetic field (IMF) that is southward and has a significant By component: the same solar wind conditions producing the event observed by the Twin Rocket Investigation of Cusp Electrodynamics-2 (TRICE-2) rockets and MMS (Fuselier et al., 2022. https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2022JA030354)...
12/15/2022Modeling ULF waves in the inner magnetosphere: A comparison between hybrid simulations and a full wave finite element modelJ. R. Johnson, Eun-Hwa Kim, Jonathan Homan, Yu Lin, Xueyi WangMore InformationPresentationPartialAGU Fall 2022 Meeting in Chicago, IllinoisPrevious theoretical and observational studies have indicated that EMIC wave perturbations play an important role in the loss of radiation belt particles in the inner magnetosphere. Because the wave-particle interactions depend sensitively on wave amplitude and polarization, it is important to accurately model the wave mode structures. In this presentation, we explore two methods to describe these waves: simulations with a 3D hybrid code in dipole geometry (GCPIC-hybrid) and a full wave finite element code, PETRA-M, that has been adapted to space plasmas. The intention is to verify performance for the two simulation methods for small wave amplitudes in the linear regime, and to identify nonlinear effects based on differences in the nonlinear regime. We consider EMIC wave generation and propagation in a dipole magnetosphere including the effect of heavy ions...
12/15/2022Turbulence in a partially ionized plasmaM. Nakanotani, G. P. Zank, and L.-L. ZhaoMore InformationPresentationPrimaryAGU Fall 2022 Meeting in Chicago, IllinoisThe local interstellar medium (LISM) around the heliosphere is a partially ionized plasma, and the plasma (MHD) and neutral fluid (HD) are coupled via several processes (e.g. charge exchange, elastic collisions, and ionization/recombination). The ionization rate is more or less 50%, the coupling effects affect the evolution of both the plasma and neutral fluid in various phenomena. In particular, since an energy cascade process is different in MHD and HD, the turbulent spectra of MHD and HD can be modified by the coupling effects. This has been verified by Shaikh & Zank 2008 in which they performed MHD simulations coupled with neutral fluid via charge-exchange...
12/14/2022Perspectives revisited: The distribution of interplanetary dust near 1-AU detected by STEREO and MMSM.L. Adrian, C. Schiff, D.C. Bradley, S.E. Letourneau, S.F. Fung, O.C. St. Cyr, M.L. KaiserMore InformationPresentationPartialAGU Fall 2022 Meeting in Chicago, IllinoisThe distribution of dust in the inner heliosphere is thought to be a roughly ellipsoidal, circumsolar disk of small debris particles produced by asteroidal collisions and comets. We quantify the distribution of micron-sized dust near 1-AU through observations made using the S/WAVES and MMS-SAMS instruments. These data indicate that dust at 1-AU is irregularly-distributed spatially in small patches of occurrence during ecliptic longitudes spanning from late summer through early winter in the Northern Hemisphere, in direct contradiction to theoretical and numerical predictions. These spatial intervals of dust patches display a strong correlation with known heliospheric mission antenna and spacecraft anomalies. Possible correlations between observed dust impact patches and known meteor showers, as well as the flow of the local interstellar cloud (LIC) through the solar system, are considered...
12/14/2022On the ultimate fate of interplanetary dustC. Schiff, M.L. Adrian, D.C. Bradley, S.E. Letourneau, S.F. FungMore InformationPresentationPartialAGU Fall 2022 Meeting in Chicago, IllinoisThrough a combination of empirical analysis and numerical simulation, we demonstrate that a rich set of dynamical behaviors govern the orbital motion of interplanetary dust and ultimately determines the fate of any dust population. The long-term evolution of a dust particle’s distance from the Sun cannot be determined, even with modest certainty, without additional in–situ observations and more sophisticated modeling. Our conclusions rest on the interplay between the gravitational, Poynting-Robertson, and Lorentz forces acting on each dust particle and the fact that, generically, the secular rate of change of any particle’s semimajor axis can dynamically transition from increasing to decreasing, and vice versa...
12/14/20223D Physics of Kinetic Alfven Waves Associated With Magnetopause Reconnection: Generation and Global TransportYu Lin, Xueyi Wang, Mark L. Adrian, and Jay R. JohnsonMore InformationPresentationPartial2022 AGU Fall Meeting, Chicago, ILKinetic mode Alfven waves (KAWs) are of great interest in space plasma physics. Having perpendicular wavelengths comparable to the ion Larmor radius, they are believed to provide efficient plasma heating and particle acceleration through wave-particle interactions. Previous studies indicate KAWs can be generated throughout the magnetosphere by processes of magnetic reconnection, wave mode conversion, and turbulent cascade. With much enhanced spatial and time resolutions in ANGIE3D, we conduct global hybrid simulations of KAWs in the magnetosphere. In this talk, we focus on the 3D physics of KAWs associated with magnetopause reconnection driven by an interplanetary magnetic field (IMF) that is southward, with a significant By component, and address the connection of nonlinear physics between the local and global dynamics...
12/13/2022Development Of An Onboard Space Weather Module For Satellite OperationPavithra Srinivas, Edmund SpencerMore InformationPresentationPrimaryAGU Fall 2022 Meeting in Chicago, IllinoisWe propose a satellite-based space weather prediction module that will predict geomagnetic storms and substorms. The capabilities of the system are to effectively communicate with other spacecraft systems and ground systems for inputs, to produce accurate results, provide data from machine learning, manage existing and incoming data, would have an easy-to-use user interface, etc...
12/13/2022A Model For Radiation Belt Electron Energization and Loss Due To Substorm InjectionsPavithra Srinivas, Edmund SpencerMore InformationPresentationPrimaryAGU Fall 2022 Meeting in Chicago, IllinoisRadiation Belt Storm Probes (RBSP) data show that seed electrons generated by substorm injections appear to play a significant role in amplifying chorus waves in the magnetosphere. The wave-particle interaction then leads to rapid heating and acceleration of the electrons which are injected into the outer Van Allen zones. In this work, we use the WINDMI model of the nightside magnetosphere to generate two proxy indices that track electron energization in the radiation belts during storm time...
12/13/2022Initiation Criteria For the Onset Of Geomagnetic Substorms Based on Auroral Observations And Electrojet Current SignaturesEdmund Spencer, Mayowa Kayode-AdeoyeMore InformationPresentationPartialAGU Fall 2022 Meeting in Chicago, IllinoisIn this work, we will show how the WINDMI model is used to analyze isolated substorms and storm time substorms when driven by solar wind activity. The model is constrained to trigger the substorms and establish the magnetospheric conditions that influence substorm dynamics. The timing of onset for each event, the model parameters and the model intermediate state space variables are examined and analyzed. We will compare the model variables and solar wind driven dynamics with the auroral observations and electrojet features...
11/4/2022Anomalous transport and acceleration of energetic particles interacting with dynamic small-scale magnetic flux rope structuresle Roux, J. A.More InformationPresentationPartial20th Annual International Astrophysics ConferenceEvidence is increasing that in a magnetically turbulent space plasma with a significant background magnetic field like the solarwind, non-propagating small-scale magnetic flux ropes (SMFRs) naturally form as part of a locally generated quasi-2D MHDturbulence component that dominates other MHD wave turbulence modes. Solar wind observations and simulations show thatenergetic particles undergo temporary trapping in SMFR structures, which is suggestive of anomalous transport. Somesimulations indicate that energetic particles undergo superdiffusion both spatially and in energy space in a turbulent plasmamedium with SMFR-like structures separated by turbulently reconnecting small-scale current sheets...
10/19/2022The Importance of Workforce Development in EPSCoR Grants and Strategies for Plasma-Focused Education and Public Engagement in AlabamaLaura ProvenzaniMore InformationPresentationPrimaryAmerican Physical Society Division of Plasma PhysicsA 2021 study from the National Science Board finds that the performance of U.S. elementary and secondary students in STEM education continues to lag that of students from other countries. The FTPP grant and the previous CPU2AL grant, funded by the NSF Established Program to Stimulate Competitive Research (EPSCoR), have put much effort into trying to contribute to the solution of this problem. In our experience, we found out that several critical areas contribute to the success of this effort...
10/19/2022Redox reactions of biologically active molecules upon cold atmospheric pressurepPlasma treatment of aqueous solutionsAlexander G. Volkov, Jewel S. Hairston, Gamaliel Taengwa, Jade Roberts, Lincoln Liburd, Darayas PatelMore InformationJournal or Juried Conf PaperPrimaryMoleculesCold atmospheric pressure plasma (CAPP) is widely used in medicine for the treatment of diseases and disinfection of bio-tissues due to its antibacterial, antiviral, and antifungal properties. In agriculture, CAPP accelerates the imbibition and germination of seeds and significantly increases plant productivity. Plasma is also used to fix molecular nitrogen. CAPP can produce reactive oxygen and nitrogen species (RONS). Plasma treatment of bio-tissue can lead to numerous side effects such as lipid peroxidation, genotoxic problems, and DNA damage. The mechanisms of occurring side effects when treating various organisms with cold plasma are unknown since RONS, UV-Vis light, and multicomponent biological tissues are simultaneously involved in a heterogeneous environment...
10/18/2022Redistribution of Kinetic Energy in a Microgravity Complex (Dusty) PlasmaLori C McCabe, Edward Thomas, Uwe Konopka, Saikat Chakraborty Thakur, Jeremiah D Williams, Mikhail Pustylnik, Hubertus ThomasMore InformationPresentationPartialAmerican Physical Society Division of Plasma PhysicsIn the presence of gravity, the micron-sized charged dust particles in a complex plasma are compressed to thin layers, but under microgravity conditions, such as the Plasma Kristall-4 (PK-4) experiment on the International Space Station (ISS), the particles fill the plasma volume which allows the study of a 3D multi-particle system. When dust particles are injected into a dc glow discharge plasma they flow along an axial electric field until stopped by periodic oscillations of the electric field (polarity switching). This oscillation creates a change in the spatial ordering and thermal state of the particle system...
10/18/2022Current research activities in the Magnetized Plasma Research Laboratory (MPRL) at Auburn UniversitySaikat Chakraborty Thakur, Uwe Konopka, Edward ThomasMore InformationPresentationPartialAmerican Physical Society Division of Plasma PhysicsThe Magnetized Plasma Research Laboratory (MPRL) at Auburn University explores a wide range of fundamental plasma and complex/dusty plasma phenomena covering the unique parameter regime of high magnetic fields (B < 4 T), at relatively low electron (Te ~ 5 eV) and ion temperature (Ti < 0.1 eV). The centerpiece of the laboratory is the Magnetized Dusty Plasma Experiment (MDPX), a highly flexible, high magnetic field plasma device with a mission to serve as an open access, multi-user collaborative research facility for the dusty plasma, basic plasma, and fusion plasma communities...
10/18/2022Growth and analysis of carbonaceous and metallic microparticles using capacitively coupled rf plasmasBhavesh Ramkorun, Saikat C Thakur, Swapneal Jain, Ryan Comes, Edward Thomas, Jr.More InformationPresentationPartialAmerican Physical Society Division of Plasma PhysicsThis presentation reports on the formation of carbonaceous nanometer to micrometer sized particle formed in a capacitively coupled rf plasma using a mixture of argon and acetylene and/or metal-organic gaseous precursors. Experiments are performed using a 13.56 MHz rf source that delivers up to 10 W of input power to various gas mixture. Particles spontaneously grow in this plasma and form a dust cloud which levitates in between the electrodes...
10/18/2022Understanding the spatiotemporal dynamics of plasma filaments at high magnetic fields via spatiotemporal image analysisDavid E Floyd,Stephen Williams,Saikat C Thakur,Edward ThomasMore InformationPresentationPrimaryAmerican Physical Society Division of Plasma PhysicsRecent experiments in the Magnetized Dusty Plasma eXperiment (MDPX) at Auburn University have shown that capacitively coupled, radio frequency generated plasmas form different kinds of filamentary structures when exposed to a high enough magnetic field (B > 1 T). Essentially, these filaments are non-uniformities in the plasma, that appear as bright vertical elongated structures parallel to the magnetic field, formed between two parallel plate electrodes...
10/18/2022Filamentation Morphology in Capacitively Coupled Highly Magnetized PlasmasStephen Williams,Saikat C Thakur,Mohamad Menati,Edward ThomasMore InformationPresentationPartialAmerican Physical Society Division of Plasma PhysicsDue to the small charge-to-mass ratio of dust particles, it is often necessary to use large magnetic fields of B ≥ 1 T, in order to observe the influence of magnetic forces in laboratory dusty plasmas. However, when experiments are performed at high magnetic fields in capacitively coupled, radio frequency discharges used for these dusty plasma experiments, the plasma is often observed to form filamentary structures between the electrodes that are aligned to the external magnetic field which disrupt the uniformity of the plasma and adversely impact some of our dusty plasma experiments...
10/18/2022Preliminary antenna-driven EM wave measurements in the ALEXIS deviceJared C Powell,Saikat Chakraborty Thakur,Edward ThomasMore InformationPresentationPartialAmerican Physical Society Division of Plasma PhysicsThe Auburn Linear Experiment for Instability Studies (ALEXIS) is capable of generating magnetized plasmas that can support a variety of plasma instabilities and waves. ALEXIS is currently configured such that strong density gradients can appear in the plasma. Recent experiments are focused on both the production and detection of both electrostatic and electromagnetic waves in the ion cyclotron to low hybrid frequency regimes in ALEXIS...
10/18/2022Nonlinear dynamics in dusty plasmas subjected to photo-dischargingMichael McKinlay,Edward Thomas,Saikat Chakraborty ThakurMore InformationPresentationPartialAmerican Physical Society Division of Plasma PhysicsExperiments on the DPX apparatus at Auburn University, indicate that LaB6 microparticles suspended in a low-temperature argon plasma can be photoelectrically discharged by a high-intensity UV source. Different particles in the experiment exhibited more periodic or chaotic responses to the discharge. In order to better understand the hypothesized role that particle shape may play in determining this behavior, a campaign of simulated discharges of ellipsoidal dust particles was generated...
10/18/2022Anomalous plasma diffusion and modified dust transport at high magnetic fields in the Magnetized Dusty Plasma Experiment (MDPX)Edward Thomas, Stephen Williams, Jared C Powell, Saikat Chakraborty Thakur, Uwe KonopkaMore InformationPresentationPartialAmerican Physical Society Division of Plasma PhysicsOperating a steady state, low temperature at high magnetic field (B > 1 T) represents a relatively unexplored regime of laboratory plasma science. Previous experiments using the MDPX device have focused on the pattern formation (filamentation), plasma and dusty plasma waves, and particle growth in a rf generated, capacitively coupled plasma (CCP) configuration. This presentation will report on recent experimental and computational studies of transport processes in strongly magnetized plasmas...
10/18/2022Development of multiple Langmuir probe designs and user-friendly probe analysis techniques for low temperature plasmas at the Magnetized Plasma Research Labs (MPRL)Matthew J Patkowski, Jared C Powell, Saikat Chakraborty Thakur, Edward ThomasMore InformationPresentationPartialAmerican Physical Society Division of Plasma PhysicsLangmuir probes are used as standard plasma diagnostic techniques in most low temperature plasma laboratories. However, depending on the specific experiment, modifications are necessary for achieving a particular goal. For example, in the RF powered linear plasma device Auburn Linear EXperiment for Instability Studies (ALEXIS), lack of RF-compensation of the Langmuir probes might lead to an artificially high electron temperature measurement. We plan to upgrade ALEXIS from a low power inductively coupled device to a higher power (~ 1 kW) helicon plasma device and hence we are constructing a new RF-compensated Langmuir probe necessary at the higher plasma densities...
10/18/2022Development of a capacitively coupled and inductively coupled dual plasma sourceAlexander D Davies, Saikat Chakraborty Thakur, Edward ThomasMore InformationPresentationPrimaryAmerican Physical Society Division of Plasma PhysicsDusty plasma is a four-component plasma consisting of electrons, ions, neutral gas, and microparticles (dust) which collect charge from the surrounding plasma environment. In situ diagnosis of a dusty plasma system with conventional probes is very challenging as the inserted probes can perturb the dust and produce voids. Hence a long-term goal is to use laser-based plasma diagnostics that can be used even in the presence of dust. Here we show the design and characterization of a dusty plasma chamber which has both capacitively and inductively coupled dual plasma sources compatible with parallel plate DC discharges and RF power...
10/18/2022Controlling the charge on dust particles using UV photo dischargingEdward Cowles, Michael McKinley, Saikat Chakraborty Thakur, Edward ThomasMore InformationPresentationPartialAmerican Physical Society Division of Plasma PhysicsDusty plasma is a four-component plasma consisting of electrons, ions, neutral gas, and microparticles (dust) which collect charge from the surrounding plasma environment. Controlling the charge on the dust particles has both academic and industrial applications. Previous research at Auburn University have shown that the charge on lanthanum hexaboride (LaB6) dust grains, suspended in a DC plasma, can be changed when exposed to an external UV source. However, due to the extremely asymmetric shapes and large size distribution of the LaB6 particles, the motion of some of the particles were stochastic and not fully under control...
10/18/2022Design and characterization of a low-cost Atmospheric Pressure Plasma Jet (APPJ)Matthew Unden,Saikat Chakraborty Thakur,Edward ThomasMore InformationPresentationPrimaryAmerican Physical Society Division of Plasma PhysicsAtmospheric Pressure Plasma Jets (APPJs) belong to the class of high pressure, room temperature plasma production mechanisms that have a large set of biological applications by killing harmful pathogens (eg. salmonella on food surfaces) or altering the surface chemistry of the target material (eg. seeds, chicken feathers). High frequency pulsed DC discharges are typically used to control the corresponding plasma characteristics. However, localized applications of a pencil like APPJ discharge and the high cost of the controlling electronics prevent scaling up of the helpful plasma application set ups...
10/18/2022Spectral measurements of neutral density in argon plasmas with widely varying fractional ionizationEleanor N Williamson, David A Maurer, Edward Thomas, Stuart D Loch, Saikat Chakraborty Thakur, David A Ennis, Curtis A Johnson, Jared C Powell, Gregory J Hartwell,More InformationPresentationPrimaryAmerican Physical Society Division of Plasma PhysicsUnderstanding the region between fully ionized and neutral dominated plasmas is important to the study of the magnetosphere of the earth, the corona/chromosphere transition region of the sun, and detached divertors in fusion devices. Determining the fractional ionization of a plasma requires accurately measuring neutral density. We use an absolute intensity calibrated spectrometer coupled with results from a collisional radiative model to infer neutral argon density. Results will be shown from benchmarking spectroscopic measurements of neutral argon density against pressure in an RF generated magnetized plasma column between 0.1 to 2.0 mTorr at 0.1% fractional ionization...
10/18/2022A New Coherence Imaging Spectroscopy Diagnostic Optimized for Ion Temperature Measurements in the W7-X Scrape-Off LayerDavid A Ennis, David M Kriete, Dorothea Gradic, Valeria Perseo, Tomas Gonda, Ralf König, David A Maurer, Saikat Chakraborty Thakur, Edward Thomas, W7-X Team (Max-Planck-Institut für Plasmaphysik)More InformationPresentationPartialAmerican Physical Society Division of Plasma PhysicsTo investigate scrape-off layer (SOL) physics in the island divertor of the W7-X stellarator a new coherence imaging spectroscopy (CIS) diagnostic is being optimized for ion temperature measurements. The CIS technique provides high-spatial-resolution measurements of ion velocity in the SOL of W7-X but ion temperature measurements are challenging due to the contribution of Zeeman splitting at high magnetic fields (B ~ 2.5 T). A technique is described for estimating the uncertainty in the ion temperature due to the spatial variation of emission along the CIS lines of sight...
10/18/2022Trapping and manipulating a single particle in dusty plasma using optical trappingPubuduni AK Ekanayaka MEW, Chuji Wang, Saikat Chakraborty Thakur, Edward ThomasMore InformationPresentationPrimaryAmerican Physical Society Division of Plasma PhysicsCurrent methods of laser manipulation in dusty plasma mostly focus on manipulating groups of particles suspended in the plasma sheath to probe collective dust-dust interactions. In this work, we report on single particle trapping and manipulations in a rf dusty plasma using the optical trapping technology. A recently-developed universal optical trap (UOT) is integrated with a rf Argon or Argon/air plasma that operates in the pressure range of tens – hundreds of millitorr, at 1-10 W...
10/18/2022Studying Time-Dependent Filamentation in Magnetized Low Temperature Plasma with MDPXElon Price, Steve Williams, Saikat Chakraborty Thakur, Edward ThomasMore InformationPresentationPartialAmerican Physical Society Division of Plasma PhysicsStudying complex or "dusty" plasmas will provide valuable insight, from diagnostics to first principles, into interdisciplinary areas of research including astrophysics, energy applications, agriculture, and medicine. Based upon the charge-to-mass ratio of the dust component, a magnetic field of B ⩾ 1 T is required in order to observe effects due to magnetic forces. However, with fields higher than 1.5 T, an instability occurs in the radio-frequency (RF) generated background plasma called filamentation...
10/6/2022Plasma self-organization in DC discharges with liquid anode: effect of electrode separation, liquid type and working gasBhagirath Ghimire, Gabe Xu, Vladimir KolobovMore InformationPresentationPartialBulletin of the American Physical SocietyWe study the formation of self-organized patterns (SOPs) in the vicinity of a liquid anode in atmospheric pressure DC glow discharges. The discharge is generated in a pin-to-liquid anode configuration with helium (He) flowing into open air. We investigate how the electrode separation and gas mixing influence the formation of SOPs on the surface of a distilled water (DIW) and 1% sodium chloride (NaCl). For a pin-to-liquid gap (g) of ~5 mm and 500 sccm He flow rate, the anode glow has the form of a circle on both DIW and NaCl surfaces. The diameter of this circle increases with increasing current. With increasing gap, multiple circles are first formed which finally transform into several more complex patterns...
10/6/2022Exploring Physics Informed Neural Networks for Solving an Anisotropic Diffusion Equation Arising in Plasma KineticsVladimir Kolobov, Lucius SchoenbaumMore InformationPresentationPartialBulletin of the American Physical SocietyWe study the formation of self-organized patterns (SOPs) in the vicinity of a liquid anode in atmospheric pressure DC glow discharges. The discharge is generated in a pin-to-liquid anode configuration with helium (He) flowing into open air. We investigate how the electrode separation and gas mixing influence the formation of SOPs on the surface of a distilled water (DIW) and 1% sodium chloride (NaCl). For a pin-to-liquid gap (g) of ~5 mm and 500 sccm He flow rate, the anode glow has the form of a circle on both DIW and NaCl surfaces. The diameter of this circle increases with increasing current. With increasing gap, multiple circles are first formed which finally transform into several more complex patterns...
10/4/2022Characteristics of DC discharges with a liquid cathode and a metal anodeBhagirath Ghimire, Gabe Xu, Vladimir KolobovMore InformationPresentationPartialBulletin of the American Physical SocietyWe will present the characteristics of atmospheric pressure direct current (DC) discharges generated between a liquid cathode and a metallic anode. Plasma is generated by purging helium (He) gas through a tungsten tube. The discharge characteristics are investigated by varying applied voltage, U, gas flow rate, inter-electrode separation, gas mixture, and cathode properties (distilled water and sodium chloride as the cathodes). At He flow rates of 800-1600 sccm and voltage U up to 3.5 kV, the glow has the form of a circle on the surface of distilled water. At higher applied voltages, a conical shape is formed...
9/29/2022Space Plasma Physics: A ReviewBruce T. Tsurutani , Gary P. Zank , Veerle J. Sterken , Kazunari Shibata , Tsugunobu Nagai , Anthony J. Mannucci , David M. Malaspina , Gurbax S. Lakhina , Shrikanth G. Kanekal , Keisuke Hosokawa , Richard B. Horne , Rajkumar Hajra , Karl-Heinz Glassmeier , C. Trevor Gaunt , Peng-Fei Chen , and Syun-Ichi AkasofuMore InformationPresentationPartialIEE Transactions on Pasma ScienceOwing to the ever-present solar wind, our vast solar system is full of plasmas. The turbulent solar wind, together with sporadic solar eruptions, introduces various space plasma processes and phenomena in the solar atmosphere all the way to the Earth's ionosphere and atmosphere and outward to interact with the interstellar media to form the heliopause and termination shock. Remarkable progress has been made in space plasma physics in the last 65 years, mainly due to sophisticated in-situ measurements of plasmas, plasma waves, neutral particles, energetic particles, and dust via space-borne satellite instrumentation. Additionally high technology ground-based instrumentation has led to new and greater knowledge of solar and auroral features. As a result, a new branch of space physics, i.e., space weather, has emerged since many of the space physics processes have a direct or indirect influence on humankind...
9/13/2022The principle of minimal powerVladimir I Kolobov and Yuri B GolubovskiiMore InformationJournal or Juried Conf PaperPartialPlasma Sources Sci. Technol. 31 (2022) 094003This article is devoted to the memory of Yuri P Raizer, who passed away in 2021. He left a noticeable trace in gas discharge physics. The principle of minimal power (the state that requires minimal power is most probable) is thoroughly used in his books. Although the fundamental laws of physics do not imply this ad hoc principle, a detailed analysis of underlying phenomena can often reveal why nature prefers this path. Raizer illustrated this principle for plasma stratification, formation of electrode spots, discharge constriction, the shape of an arc channel, etc. We argue that the nonlinearity of equations describing gas discharges can often justify the realization of a plasma state maintained at minimal electric power. This nonlinearity appears because small groups of energetic electrons often control the ionization processes...
7/24/2022Using a new fractional Parker Transport Equation to model superdiffusive shock acceleration at a parallel shockle Roux, J. A.More InformationPresentationPartial44th COSPAR MeetingIt has been suggested before that small-scale magnetic flux rope (SMFR) structures in the solar wind can temporarily trap energetic charged particles. We recently derived a new fractional Parker equation for energetic particle interaction with SMFRs in the large-scale supermagnetosonic solar wind flow that can account for such trapping effects (le Roux 2022). The new equation suggests that parallel transport of energetic particles through SMFRs is characterized by superdiffusion that increasingly dominates advection effects with time. Parallel superdiffusion can be linked back to underlying anomalous pitch-angle transport which might be subdiffusive during interaction with SMFRs...
7/24/2022Investigating the relative roles of SMFR acceleration mechanisms on particle acceleration behind traveling shocks inside 1 AUVan Eck, K. T., le Roux, J. A., Zhao, L.-L.More InformationPresentationPartial44th COSPAR MeetingTraditionally, diffusive shock acceleration (DSA) has been invoked to explain energetic particle flux enhancements in the large-scale solar wind. However, recent studies suggest that acceleration processes related to magnetic reconnection behind traveling shocks occurring in the vicinity of interplanetary coronal mass ejections (ICMEs), which are a major factor in space weather, can explain observed flux enhancements that contradict predictions by standard steady state DSA theory. A better way of interpreting flux enhancements in the vicinity of traveling shocks might be to consider a combination of DSA and acceleration by dynamic small-scale flux-rope (SMFR) downstream...
7/5/2022Investigating particle acceleration by dynamic small-scale flux ropes behind interplanetary shocks in the Inner HeliosphereVan Eck, K. T., le Roux, J. A., Chen, Y., Zhao, L.-L., Thompson, N.More InformationJournal or Juried Conf PaperPartialThe Astrophysical JournalWe recently extended our Parker-type transport equation for energetic particle interaction with numerous dynamic small-scale magnetic flux ropes (SMFRs) to include perpendicular diffusion in addition to parallel diffusion. We present a new analytical solution to this equation assuming heliocentric spherical geometry with spherical symmetry for all SMFR acceleration mechanisms present in the transport theory. With the goal of identifying the dominant mechanism(s) through which particles are accelerated by SMFRs, a search was launched to identify events behind interplanetary shocks that could be explained by our new solution and not classical diffusive shock acceleration...
7/1/2022Impact of magnetic focusing on the origin of electron beams propagating upwardly in the Solar CoronaB. Tang, H. Che, Z. P. Zank, V. KolobovMore InformationPresentationPartialShine 2022 ConferenceFlare produced electron beams are widely believed to responsible for type III radio bursts. The height of the starting frequency of type III radio bursts is found commonly higher than the site of particle acceleration region of solar flares. The magnetic focusing effect, converting electron kinetic energy from perpendicular to parallel, alone is capable of accelerating the non-thermal electrons in the lower corona to reach and exceed the threshold of nonlinear electron two stream instability within an altitude of 0.5 solar radii as the electrons propagating away from the initial acceleration site along the magnetic field line...
7/1/2022The impact of domain size on magnetic reconnection simulations on electron acceleration by the electron Kelvin-Helmholtz InstabilityC. Crawford, H. CheMore InformationPresentationPartialShine 2022 ConferenceA new nonlinear magnetic reconnection (MR) acceleration mechanism was recently brought forward, in which electrons are accelerated by an electron Kelvin-Helmholtz instability (EKHI), which is driven by inherent electron velocity shear in a force-free current sheet during magnetic reconnection with a strong guide field. We use three particle-in-cell simulations of increasingly larger domain size to conduct an analysis of the impact of domain size on the mechanism. We found that with the increase in domain size, the MR timescale increases due to an increase in magnetic energy stored in the current sheet...
6/30/2022Using dusty plasmas to probe pattern formation at high magnetic fields in the Magnetized Dusty Plasma Experiment (MDPX) deviceE. Thomas, S. Williams, S. Chakraborty Thakur, U. Konopka,PresentationPartial2022 MagNetUS meetingNA