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We calculate the time‐varying spatial distribution of energetic magnetospheric electron influx onto Europa's surface by combining a hybrid model of the moon's draped electromagnetic environment with a relativistic particle tracer. We generate maps of the energetic electron influx patterns at four distinct locations of Europa relative to the center of the Jovian magnetospheric current sheet. For a full synodic rotation of Jupiter, these results are applied to constrain the averaged number and energy influx patterns as well as the O2 sputtering rates associated with energetic electron precipitation. We also determine the relative contributions of magnetospheric ions and electrons to surface erosion and exospheric genesis at Europa. Our major results are: (a) Except for a small region near Europa's downstream apex, the moon's entire surface is exposed to heavy irradiation by magnetospheric electrons. (b) The spatial distribution of energetic electron influx onto Europa's surface is only slightly modified by field line draping and the induced magnetic field from the moon's subsurface ocean. (c) The contributions of magnetospheric electron and ion impacts to energy deposition onto Europa's surface are of the same order of magnitude. (d) Within uncertainties, impinging magnetospheric electrons and ions make similar contributions to O2 sputtering from Europa's surface. (e) The spatial distribution of electron energy influx and the observed concentrations of sulfuric acid (H2SO4) are only weakly correlated, suggesting that energy deposition by magnetospheric electron impacts is not a necessary agent for H2SO4 production within Europa's surface. Key Points: Europa's plasma interaction and induced magnetic field cause only subtle changes to energetic electron influx patterns on the moon's surfaceIntegrated across Europa's entire surface, impinging magnetospheric electrons deposit a similar amount of energy as magnetospheric ionsMagnetospheric electron and ion impacts release comparable numbers of oxygen molecules from Europa's surface into the moon's exosphere [ABSTRACT FROM AUTHOR]

This study investigates the lunar plasma environment when embedded within Earth's magnetotail. We use data from 10 years of tail crossings by the Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon's Interaction with the Sun (ARTEMIS) spacecraft in orbit around the Moon. We separate the plasma environments by magnetosheath‐like, magnetotail lobe‐like, and plasma sheet‐like conditions. Our findings highlight that the lobe‐like plasma is associated with low densities and a strong magnetic field, while the plasma sheet is characterized by higher densities and a weaker magnetic field. These regions are flanked by the fast, predominantly tailward flows of the terrestrial magnetosheath. During a single lunar crossing, however, the magnetotail displays a wide range of variability, with transient features—including reconnection events—intermixed between periods of lobe‐like or sheet‐like conditions. We compare and contrast the Moon's local magnetotail plasma to the environments near various outer‐planet moons. In doing so, we find that properties of the ambient lunar plasma are, at times, unique to the terrestrial magnetotail, while at others, may resemble those near the Jovian, Saturnian, and Neptunian moons. These findings highlight the complementary role of the ARTEMIS mission in providing a deeper understanding of the plasma interactions of the outer‐planet moons. Key Points: We use 10 years of data from the Time History of Events and Macroscale Interactions during Substorms‐Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon's Interaction with the Sun mission to constrain the lunar plasma environment within the terrestrial magnetotailWe identify three predominant distributions of the magnetotail plasma, corresponding to the magnetosheath, lobes, and plasma sheetFor these conditions, we calculate statistical properties of the local magnetic field, plasma bulk velocity, number density, and temperature [ABSTRACT FROM AUTHOR]

We present observations of the Moon's plasma interaction in Earth's magnetotail lobes by the ARTEMIS mission, and compare these to hybrid model results to constrain the global properties of the lunar electromagnetic environment. We identify, for the first time in the magnetotail lobes, a low‐energy wake extending multiple lunar radii downstream of the Moon along the ambient flow direction. This wake is tilted out of the lunar optical shadow, allowing for detection of the otherwise unobservable cold ambient magnetospheric plasma. Similar eclipse encounters may provide additional opportunities to measure this low‐energy plasma potentially originating from the terrestrial ionosphere. We find lunar ionospheric outflow extending multiple Moon radii downstream that generates asymmetries in the Moon's plasma environment and shares characteristics with the plasma interactions of Rhea, Tethys, and Dione. The extensive ARTEMIS data set may therefore provide additional insights into the plasma environments near moons of the outer solar system. Plain Language Summary: Earth's Moon is exposed to a wide range of particle and magnetic field environments during its 29.5‐day orbit. When outside of Earth's magnetosphere, the Moon experiences the rapidly flowing, dense solar wind plasma. However, for a few days each month, the terrestrial magnetosphere shields the Moon from the solar wind; instead, it is exposed to the low‐density plasma within Earth's magnetotail lobes. For these conditions, we report observations from the Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon's Interaction with the Sun (ARTEMIS) spacecraft orbiting the Moon. By modeling the Moon's plasma interaction in the lobes, we find that dense, lunar ionospheric particles drastically perturb the local plasma environment, similar to moons in the outer solar system. On the nightside, we provide the first observation of an extended, cold plasma wake tilted out of the Moon's optical shadow. This geometry allowed ARTEMIS to measure an otherwise invisible, ambient magnetospheric ion population that is responsible for shaping the lunar plasma interaction. Hence, the Moon acts as a natural filter for plasma observations in the Earth's magnetotail, an effect that may therefore be used to understand loss processes of Earth's ionospheric plasma. Key Points: We provide the first observational and modeling evidence of a cold ion wake downstream of the Moon when located in Earth's magnetotail lobesUsing the Moon as a natural solar shield, we reveal an otherwise hidden, cold ion population that may originate from Earth's ionosphereThe lunar plasma environment in the terrestrial magnetotail lobes provides a link to the plasma interactions at outer solar system moons [ABSTRACT FROM AUTHOR]

Europa hosts a periodically changing plasma interaction driven by the variations of Jupiter's magnetic field and magnetospheric plasma. We have developed a multi‐fluid magnetohydrodynamic (MHD) model for Europa to characterize the global configuration of the plasma interaction with the moon and its tenuous atmosphere. The model solves the multi‐fluid MHD equations for electrons and three ion fluids (Jupiter's magnetospheric O+, as well as O+ and O2+ originating from Europa's atmosphere) while incorporating sources and losses in the MHD equations due to electron impact and photo‐ionization, charge exchange, recombination and other relevant collisional effects. Using input parameters constrained by the Galileo magnetic field and plasma observations, we first demonstrate the accuracy of our model by simulating the Galileo E4 and E14 flybys, which took place under different upstream conditions and sampled different regions of Europa's interaction. Our model produces 3D magnetic field and plasma bulk parameters that agree with and provide context for the flyby observations. We next present the results of a parameter study of Europa's plasma interaction at three different excursions from Jupiter's central plasma sheet, for three different global magnetospheric states, comprising nine steady‐state simulations. By separately tracking multiple ion fluids, our MHD model allows us to quantify the access of the Jovian magnetospheric plasma to Europa's surface and determine how that access is affected by changing magnetospheric conditions. We find that the thermal magnetospheric O+ precipitation rate ranges from (1.8–26) × 1024 ions/s, and that the precipitation rate increases with the density of the ambient magnetospheric plasma. Plain Language Summary: The moon Europa is embedded within Jupiter's magnetosphere, a region of space dominated by Jupiter's powerful magnetic field. The magnetosphere is filled with charged particles (plasma) which originate mainly from Jupiter's moon Io. Jupiter's magnetic field and plasma circulate throughout the magnetosphere. They flow around Europa and pile up as they approach Europa's ionosphere, a layer of plasma that surrounds the moon and partially shields the surface from the impact of Jupiter's magnetospheric plasma. Europa's ionosphere is generated from its atmosphere, which is in turn generated by surface sputtering, a process in which neutral particles are released when charged particles strike Europa's icy surface. We have developed a computational model for Europa's space environment. We used the model to study how the changing conditions of Jupiter's magnetosphere affect the number and temperature of magnetospheric particles that are able to reach Europa's surface. With this result we can better understand the effect of conditions in Jupiter's magnetosphere on sputtering and, subsequently, on Europa's atmosphere. Understanding Europa's atmosphere and space environment will be critical for interpreting the observations of NASA's upcoming Europa Clipper mission. Key Points: We present a new multi‐fluid magnetohydrodynamic model for Europa's plasma interaction, validated against data from the Galileo E4 and E14 flybysOur model estimates a thermal O+ precipitation rate of (1.8–26)×1024 ions/s over the probable range of Jovian magnetospheric conditionsThe plasma interaction causes thermal magnetospheric plasma to precipitate on Europa's leading/downstream hemisphere [ABSTRACT FROM AUTHOR]

The Galilean moons play major roles in the giant magnetosphere of Jupiter. At the same time, the magnetospheric particles and fields affect the moons. The impact of magnetospheric ions on the moons' atmospheres supplies clouds of escaping neutral atoms that populate a substantial fraction of their orbits. At the same time, ionization of atoms in the neutral cloud is the primary source of magnetospheric plasma. The stability of this feedback loop depends on the plasma/moon‐atmosphere interaction. The purpose of this review is to describe the physical processes that shape the space environment around the two innermost Galilean moons—Io and Europa—and to show their impact from the planet Jupiter out into interplanetary space. Key Points: Io and Europa substantially impact the Jovian magnetosphere while interactions of plasma with moons affects their surfaces and atmospheresTen components are described, including neutrals, thermal plasma, and energetic particles, spanning from Jupiter to interplanetary mediumCurrent understanding of the systems and processes are reviewed with a summary of outstanding questions [ABSTRACT FROM AUTHOR]

The interaction between the Io plasma torus and Io exhibits significant dynamics resulting from temporal variations of both external conditions in the plasma torus and local conditions in Io's environment. We present analysis of an extensive simulation campaign of the Io plasma interaction under varying interaction conditions performed by using a hybrid multispecies simulation model. We test two models of electron impact ionization, one resulting in plasma production constrained to the upstream hemisphere of Io and the other producing a more symmetric distribution of the plasma with nonnegligible plasma production on the downstream side of Io. In the latter case, the simulation model provides high level of agreement with Galileo measurements of magnetic field obtained during the I0 flyby, where the model captures even smaller‐scale features of the magnetic field profile. Our simulated results provide strong support for the existence of Io's induced dipole field. In this model we assume that induced dipole field moment is antiparallel to the direction of the inducing magnetic field, equivalent to induction in a highly conductive Io. Our results further support the idea that Io's atmosphere collapsed during the Galileo I27 flyby, which manifests itself in the lack of ion heating due to pickup processes in the extended atmosphere. Our results show that the dominant torus species, O+ and S++, are depleted around Io and may exhibit temperature anisotropy, T⊥/T‖ < 1, resulting from merging of ion populations coming from opposite sides of Io along the magnetic field. Key Points: A nonnegligible ion source on the downstream side of Io is required to explain Galileo observationsSimulated results provide strong support for the existence of Io's induced dipole fieldDominant torus species have parallel temperature exceeding the perpendicular temperature close to Io [ABSTRACT FROM AUTHOR]

Mercury is the closest orbiting planet around the sun and is therefore embedded in an intensive and highly varying solar wind. In-situ data from the MESSENGER spacecraft of the plasma environment near Mercury indicates that a coronal mass ejection (CME) passed the planet on 23 November 2011 over the span of the 12 h MESSENGER orbit. Slavin et al. (2014) derived the upstream parameters of the solar wind at the time of that orbit, and were able to explain the observed MESSENGER data in the cusp and magnetopause segments of MESSENGER's trajectory. These upstream parameters will be used for our first simulation run. We use the hybrid code A.I.K.E.F. which treats ions as individual particles and electrons as a mass-less fluid, to conduct hybrid simulations of Mercury's magnetospheric response to the impact of the CME on ion gyro time scales. Results from the simulation are in agreement with magnetic field measurements from the inner day-side magnetosphere and the bow-shock region. However, at the planet's nightside, Mercury's plasma environment seemed to be governed by different solar wind conditions, in conclusion, Mercury's interaction with the CME is not sufficiently describable by only one set of upstream parameters. Therefore, to simulate the magnetospheric response while MESSENGER was located in the tail region, we use parameters obtained from the MHD solar wind simulation code SUSANOO (Shiota et al. (2014)) for our second simulation run. The parameters of the SUSANOO model achieve a good agreement of the data concerning the plasma tail crossing and the night-side approach to Mercury. However, the polar and closest approach are hardly described by both upstream parameters, namely, neither upstream dataset is able to reproduce the MESSENGER crossing of Mercury's magnetospheric cusp. We conclude that the respective CME was too variable on the timescale of the MESSENGER orbit to be described by only two sets of upstream conditions. Our results suggest locally strong and highly variable dynamics of the CME on timescales of 15 min while MESSENGER was near closest approach. [ABSTRACT FROM AUTHOR]

Most planetary bodies are moving in the solar wind, in a stellar wind, or in a plasma flow within the magnetosphere of a planet. The interaction of the body with the flowing plasma provides us with various interaction types, which mainly depend on the flow speed, the magnetization of the body, its conductivity, the presence of an ionosphere, and the size of the body. We establish two cornerstones representing highly magnetized obstacles embedded in a super-Alfvénic and sub-Alfvénic plasma. Those two cornerstones complete the two cornerstones defined in our previous study on inert obstacles in super-Alfvénic and sub-Alfvénic regimes. Tracking the transitions between these cornerstones enable better understanding of the feedback of the obstacle onto the plasma flow. Each interaction is studied by means of the hybrid model simulation code AIKEF. The results are summarized in three dimensional diagrams showing the current structures, which serve as a basis for our descriptions. We identify the major currents such as telluric, magnetosonic, Chapman–Ferraro, and bow-shock currents as the signatures of the particular state of development of the interaction region. We show that each type of interactions can be identified by studying the shape and the magnitude of its specific currents. [ABSTRACT FROM AUTHOR]

One of the goals of the upcoming MAVEN mission to Mars is to investigate the effects of the crustal remanent fields on the solar wind plasma interaction and the upper atmosphere. The MGS Electron Reflectometer and magnetometer observations can be used to test the idea that, if the future data from the electron spectrometer (SWEA) are separated for the two prevalent interplanetary field orientations (Parker spirals ׳toward׳ and ׳away׳ from the Sun), one may be able to detect specific differences in the pattern of locations of open magnetic fields (where photoelectrons can escape from Mars׳ ionosphere into space), as well as patterns of photoelectrons in the Martian magnetotail. We use a pair of BATS-R-US MHD model results of the Mars–solar wind interaction, in a manner similar to that tested by Liemohn et al. in 2006 on Mars Express ELS electron data, to define these patterns of expected photo-electron detections on a global scale. Those cases have the strongest southern hemisphere crustal fields at noon or midnight, a matter of importance in such investigations because these patterns will be sensitive to the local time of those fields. We compare some MGS data-based maps of the time periods selected for their open field signatures in the pitch angle distributions and energy spectra, and separated by interplanetary field orientation inferred from Mars magnetosheath observations. This exercise illustrates the power (and necessity) of the global model comparisons as a means of interpreting the very complex Mars–solar wind interaction and its effects. [ABSTRACT FROM AUTHOR]

In the advent of the Rosetta arrival at the comet 67P/Churyumov–Gerasimenko, we present a global 3D hybrid simulation model of the cometary plasma interaction which resolves the innermost coma sufficiently. As Rosetta will only provide local information, global simulations are required to put these local observations into a wider global perspective. In the selected scenario close to the perihelion, the gas production of the comet is large enough to trigger a cometary bow shock and a small diamagnetic cavity around the nucleus. The simulation reveals the presence of a cometary ionopause and a recombination layer, which is in general agreement with single-fluid MHD simulations. However, we found an asymmetry in the interaction region caused by the pick-up of the cometary ions, which effects all known boundaries. In addition, we study the velocity distributions of the ions and find the presence of three distinct populations of cometary ions at the inner boundaries. The bifurcation created in the ion energy spectrum might be observable by the instruments onboard the Rosetta spacecraft. [ABSTRACT FROM AUTHOR]

A series of spacecraft charging analyses was carried out for large GEO satellites using Multi-Utility Spacecraft Charging Analysis Tool. The purpose was to derive the number of electrostatic discharges expected for 15 years in orbit, which would be used as the basis of the number of primary electrostatic discharges (ESDs) to be used in future solar cell coupon ESD tests. The combinations of GEO plasma parameters (electron density, proton density, electron energy, and proton energy) that have a high probability of occurrence have been identified first. For each of those plasma parameters, a charging analysis was done. In the simulation, the time for the differential voltage between solar array cover glass and the spacecraft chassis to reach the ESD inception threshold was calculated. The results indicate that, for a typical GEO satellite, the expected number of ESDs in 15 years is on the order of 10 000, agreeing well with the previous work where another satellite was simulated by NASCAP/GEO. [ABSTRACT FROM AUTHOR]

The formation of Titan's induced magnetosphere is a unique and important example in the solar system of a plasma-moon interaction where the moon has a substantial atmosphere. The field and particle conditions upstream of Titan are important in controlling the interaction and also play a strong role in modulating the chemistry of the ionosphere. In this paper we review Titan's plasma interaction to identify important upstream parameters and review the physics of Saturn's magnetosphere near Titan's orbit to highlight how these upstream parameters may vary. We discuss the conditions upstream of Saturn in the solar wind and the conditions found in Saturn's magnetosheath. Statistical work on Titan's upstream magnetospheric fields and particles are discussed. Finally, various classification schemes are presented and combined into a single list of Cassini Titan encounter classes which is also used to highlight differences between these classification schemes. [ABSTRACT FROM AUTHOR]

Abstract: Using minimum variance analysis of the circular mapping data from the Mars Global Surveyor (MGS) spacecraft during four selected weeks of observation, we identify 360 magnetic field structures in the Martian topside ionosphere with characteristic signatures of flux ropes. Physical parameters including size, peak field strength, helicity, orientation, and external conditions at the time of each observation are compiled for the events in each population. We observe that Martian flux ropes typically have a peak field amplitude of ∼15nT and a diameter of ∼80–100km assuming they are stationary. Flux ropes tend to be aligned approximately parallel to the planetary surface, and perpendicular to the direction from which the solar wind flows. They are more frequently observed during times of low solar wind pressure, but do not show a clear preference for a particular Interplanetary Magnetic Field (IMF) draping direction. Flux rope characteristics of peak field amplitude, diameter, and helicity vary with solar zenith angle. Amplitudes tend to be higher during periods of high solar wind pressure. The events are sorted into three populations based on the location at which they were observed, possibly corresponding to distinct formation mechanisms. Flux ropes observed in eclipse tend to have smaller peak amplitudes and are larger than those observed in sunlight, and are less likely to be oriented parallel to the planetary surface. Proximity to crustal fields does not appear to influence the characteristics of flux ropes observed at the 400km spacecraft altitude. The frequent observation of flux rope structures near Mars in a variety of locations suggests that the low-altitude plasma environment is quite dynamic, with magnetic shear playing a prominent role in determining magnetic field structure near the planet. [Copyright &y& Elsevier]

Abstract: Observations of unusually large magnetic fields in the ionosphere indicate periods of maximum stress on Titan’s ionosphere and potentially of the strongest loss rates of ionospheric plasma. During Titan flyby T42, the observed magnetic field attained a maximum value of 37nT between an altitude of 1200 and 1600km, about 20nT stronger than on any other Titan pass and close to five times greater in magnetic pressure. The strong fields occurred near the corotation-flow terminator rather than at the sub-flow point, suggesting that the flow which magnetized the ionosphere was from a direction far from corotation and possibly towards Saturn. Extrapolation of solar wind plasma conditions from Earth to Saturn using the University of Michigan MHD code predicts an enhanced solar wind dynamic pressure at Saturn close to this time. Cassini’s earlier exits from Saturn’s magnetosphere support this prediction because the Cassini Plasma Spectrometer instrument saw a magnetopause crossing three hours before the strong field observation. Thus it appears that Titan’s ionosphere was magnetized when the enhanced solar wind dynamic pressure compressed the Saturnian magnetosphere, and perhaps the magnetosheath magnetic field, against Titan. The solar wind pressure then decreased, leaving a strong fossil field in the ionosphere. When observed, this strong magnetic flux tube had begun to twist, further enhancing its strength. [Copyright &y& Elsevier]

The paper is devoted to the study of plasma effects, which are present in laser ablation at relatively high intensity (I ≥ 1012 W/cm²). We start from the classical "two temperature model" of laser ablation ("cold solid approximation") and we extend it to higher intensities where laser-induced heating and laser-induced changes in the background material become relevant. The new model is also compared to experimental results on laser ablation of solid targets from short pulse lasers at high intensities (up to 1014 W/cm²). Finally, we consider the effects on laser-ablation of laser-generated fast electrons. [ABSTRACT FROM AUTHOR]

The electrodynamic bare tether system shows a promise of efficient electron current collection. Several problems associated with the use of the bare tether were investigated, such as anomalous current collection due to ionization of the neutral gas, negative arcs, and heating by current collection. These phenomena may adversely affect the control of the tether system. In this paper, we performed ground experiments and numerical simulations. In the positive-bias experiment, the anomalous electron current collection occurred when the tether potential was greater than 170 V in Xe plasma of 3.5 x 1012-m-3 density and 2.5-eV temperature with back pressure of 9.7 x 10-3 Pa. We also performed surface-temperature measurement of the bare tether. The tether was heated by impacting electrons to a temperature higher than 120 °C for the tether potential of 270 V and a current of 25 mA/m. In the negative-bias experiment, the tether samples with less conductive fibers or insulator coating arced at negative voltage as low as -200 V. [ABSTRACT FROM AUTHOR]

Abstract: Amorphous hydrogenated silicon (a-Si:H) belongs still to most promising types of semiconductors for its utilization in fabrication of TFTs and thin film solar cell technology due to corresponding cheap a-Si:H-based device production in comparison with, e.g. crystalline silicon (c-Si) technologies. The contribution deals with both two important modes of preparation of very-thin and ultra-thin silicon dioxide films in the surface region of a-Si:H semiconductor (oxygen plasma sources and liquid chemical methods) and electrical, optical and structural properties of produced oxide/semiconductor structures, respectively. Dominant aim is focused on investigation of oxide/semiconductor interface properties and their comparison and evaluation from view of utilization of used technological modes in the nanotechnological industry. Following three basic types of oxygen plasma sources were used for the first time in our laboratories for treatments of surfaces of a-Si:H substrates: (i) inductively coupled plasma in connection with its applying at plasma anodic oxidation; (ii) rf plasma as the source of positive oxygen ions for plasma immersion ion implantation process; (iii) dielectric barrier discharge ignited at high pressures. The liquid chemical manner of formation SiO2/a-Si:H structures uses 68wt% nitric acid aqueous solutions (i.e., azeotropic mixture with water). Their application in crystalline Si technologies has been presented with excellent results in the formation of ultra-thin SiO2/c-Si structures [H. Kobayashi, M. Asuha, H.I. Takahashi, J. Appl. Phys. 94 (2003) 7328]. Passivation of surface and interface states by liquid cyanide treatment is additional original technique applied after (or before) formation of almost all formed thin film/a-Si:H structures. Passivation process should be used if high-quality electronical parameters of devices can be reached. [Copyright &y& Elsevier]

Induced magnetospheres occur around planetary bodies that are electrically conducting or have substantial ionospheres, and are exposed to a time-varying external magnetic field. They can also occur where a flowing plasma encounters a mass-loading region in which ions are added to the flow. In this introduction to the subject we examine induced magnetospheres of the former type. The solar wind interaction with Venus is used to illustrate the induced magnetosphere that results from the solar wind interaction with an ionosphere. [Copyright &y& Elsevier]

The sustained arcing mechanism in the solar arrays of Engineering Test Satellite-VIII (ETS-VIII) due to the failure of the ion thruster neutralizer and due to the development of inverted potential gradient on the solar arrays in the geosynchronous earth orbit (GEO) is presented. Failure of the ion thruster neutralizer is simulated in a laboratory, and the sustained arc is observed at the gap between the adjacent cells of the solar array without room temperature vulcanization silicon grouting with a potential difference of 55 V and a current of 2.64 A. The grouting prevents a sustained arc even under the worst condition expected for the satellite. The sustained arc is observed bridging two interconnectors separated by 6 cm with an inter-string voltage of 130 V and a current of 2.64 A for the array with RTV grouting. In a simulated GEO environment, it is confirmed that the sustained arc does not occur between the adjacent array strings as long as silicon rubber grouts the gap between the strings. We observed another type of sustained arc between the array strings and the aluminum honeycomb substrate through defect on the Kapton sheet in a simulated GEO environment. Based on the test results, modification of the array design is possible. [Copyright &y& Elsevier]

We characterized different cationic lipid-based gene delivery systems consisting of both liposomes and nonliposomal structures, in terms of their in vitro transfection activity, resistance to the presence of serum, protective effect against nuclease degradation and stability under different storage conditions. The effect of lipid/DNA charge ratio of the resulting complexes on these properties was also evaluated. Our results indicate that the highest levels of transfection activity were observed for complexes prepared from nonliposomal structures composed of FuGENE 6. However, their DNA protective effect was shown to be lower than that observed for cationic liposome formulations when prepared at the optimal (+/−) charge ratio. Our results suggest that lipoplexes are resistant to serum up to 30% when prepared at a 2:1 lipid/DNA charge ratio. However, when they were prepared at higher (+/−) charge ratios, they become sensitive to serum for even lower concentrations (10%). Replacement of dioleoyl-phosphatidylethanolamine (DOPE) by cholesterol enhanced the resistance of the complexes to the inhibitory effect of serum. This different biological activity in the presence of serum was attributed to different extents of binding of serum proteins to the complexes, as evaluated by the immunoblotting assay. Studies on the stability under storage show that lipoplexes maintain most of their biological activity when stored at −80 °C, following their fast freezing in liquid nitrogen. [Copyright &y& Elsevier]

We study the dynamics of the thermal O + and H + ions at Ganymede's magnetopause when Ganymede is inside and outside of the Jovian plasma sheet using a three-dimensional hybrid model of plasma (kinetic ions, fluid electrons). We present the global structure of the electric fields and power density ( E  ⋅  J ) in the magnetosphere of Ganymede and show that the power density at the magnetopause is mainly positive and on average is +0.95 and +0.75 nW/m 3 when Ganymede is inside and outside the Jovian plasma sheet, respectively, but locally it reaches over +20 nW/m 3 . Our kinetic simulations show that ion velocity distributions at the vicinity of the upstream magnetopause of Ganymede are highly non-Maxwellian. We investigate the energization of the ions interacting with the magnetopause and find that the energy of those particles on average increases by a factor of 8 and 30 for the O + and H + ions, respectively. The energy of these ions is mostly within 1-100 keV for both species after interaction with the magnetopause, but a few percentages reach to 0.1-1 MeV. Our kinetic simulations show that a small fraction ( < 25%) of the corotating Jovian plasma reach the magnetopause, but among those >50% cross the high-power density regions at the magnetopause and gain energy. Finally, we compare our simulation results with Galileo observations of Ganymede's magnetopause crossings (i.e., G8 and G28 flybys). There is an excellent agreement between our simulations and observations, particularly our simulations fully capture the size and structure of the magnetosphere., (© 2022 The Authors.)

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Scaling of large area atmospheric pressure plasma jet arrays remains a key challenge due to electrical and hydrodynamical coupling between individual plasma jets. Here, we present a novel means by which to obtain a large-volume large-surface-area atmospheric plasma jet array in helium. The individual jets of the plasma jet array are confined to expand in a secondary jet tube. The secondary jet tube assists the individual jets in mixing to form a single large-volume large-surface-area plasma jet on a downstream substrate. It is envisaged that the present system will facilitate more homogeneous treatment of large surface areas in both surface treatment and plasma medicine applications. [ABSTRACT FROM AUTHOR]

The goal of our study is to present a systematic modeling framework for the identification of water vapor plumes in plasma and magnetic field data from spacecraft flybys of Europa. In particular, we determine the degree to which different plume configurations can be obscured by the interaction of Jupiter's magnetospheric plasma with Europa's induced dipole field and its global atmosphere. We apply the hybrid model AIKEF (kinetic ions, fluid electrons) to investigate the effect of inhomogeneities in Europa's atmosphere (plumes) on the plasma interaction with the Jovian magnetosphere. To systematically assess the magnitude and structure of the perturbations associated with the plume‐plasma interaction at Europa, we vary the plume location across Europa's surface while considering different symmetric and asymmetric density profiles of the moon's global atmosphere. To isolate the impact of a plume on Europa's magnetospheric environment, we also conduct model runs without any global atmosphere. To quantify the magnetic perturbations caused by plumes, we analyze the field components along hypothetical spacecraft trajectories through each plume. Conclusions of our study are (1) localized regions of stagnant flow are most indicative of the presence of a plume. (2) The visibility of plumes in the magnetic field strongly depends on the density profile (whether it is symmetric or asymmetric) of the global atmosphere. (3) The presence of an induced dipole complicates the identification of magnetic signatures associated with a plume and dominates Europa's magnetic environment in its intermediate vicinity. (4) Complex fine structures are visible in the tail of escaping plume ions. Key Points: Localized regions of stagnant flow are most indicative of the presence of a plume at EuropaThe visibility of plumes in spacecraft data highly depends on the density profile of the global atmosphere and the presence of an induced dipolePrecise knowledge of the plasma's upstream parameters is required to identify plumes in spacecraft data [ABSTRACT FROM AUTHOR]