In reconnection, the presence of heavy ions like O+ increases the ion mass density reducing the fluid's Alfvén speed. In addition, it may modify the reconnection structure, which can also change the ...reconnection rate. However, because O+ ions have a larger Larmor radii than H+ ions at the same velocity, they may not be fully entrained in the reconnection flow and may have kinetic effects other than just increasing the mass density. In this study, for the first time, the ion velocity distribution functions of H+ and O+ from one magnetopause reconnection event with a strong guide field are analyzed to determine in detail the behavior of the different ion populations. We show that the hot magnetospheric O+ ions, along with the hot magnetospheric H+ ions almost fully participate in the reconnection exhaust flows. Finite Larmor radius effects are also apparent and control how far the ions extend on the magnetosheath side. Ion signatures consistent with heating after being picked up in the reconnection exhaust flow are observed in the H+ and O+ distribution functions. The dynamics of the cold magnetospheric ions depends on where they enter the reconnection region. If they enter the reconnection region at the downstream separatrix, they will be taken away by the magnetic field in an adiabatic way as analyzed by Drake et al. (2009a); if they enter close to the diffusion region, they behave as pick‐up ions.
Key Points
Hot O+ from the magnetosphere follows the reconnection exhaust flow
The behavior of cold ions depends on where they enter the reconnection region
Finite Larmor radius effects are also observed for the magnetopheric hot ions
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract LION is a laser ion source that has been in operation at Brookhaven National Laboratory (BNL) to provide heavy ions for NASA Space Radiation Laboratory (NSRL) and Relativistic Heavy Ion ...Collider (RHIC). It is the first laser ion source to supply stable ion beams for a long-term operation for users at a large accelerator facility in the world. LION is located at the upstream end of the heavy ion accelerator complex at BNL and supplies singly charged ion beams of various ion species. LION has been in operation since 2014 and is planned to be upgraded in 2024. This paper summarizes the operational performance achieved by LION.
Groundwater represents a significant source of fresh water for drinking purposes and, therefore, preserving its availability and quality is extremely important. The hydrochemical characteristics and ...quality of groundwater in Ejisu-Juaben Municipality, Ghana have been evaluated based on different indices for assessing groundwater for drinking purposes. A total of 19 groundwater samples were collected and analyzed for major cations and anions using standard methods. The results show that the groundwater parameters were within the permissible limits of the World Health Organization except phosphate. The domination of major ions was in the order of Ca
2+
> Mg
2+
> NH
4
+
for cations and Cl
−
> HCO
3
−
> SO
4
2−
> PO
4
2−
> NO
3
−
> NO
2
−
in anions. The hydrochemical analysis suggest that the dominant ions were derived from ion exchange and silicate weathering process. According to Gibbs plot, the predominant samples fall in the rock–water interaction and precipitation dominance field. The R-mode factor analysis shows that the four factors extracted account for 83.9 % of the total variance. Groundwater quality index reveals that the majority of the samples falls under good to excellent category of water, suggesting that the groundwater is suitable for drinking and other domestic uses.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
•Secondary ions TinFemHk± are indicative of chemisorbed H presence on TiFe surface.•Yield dependences on H concentration are different for different secondary ions.•H presence increases yields of Ti+ ...and Ti-containing positive cluster ions.•Temperature-independent H2 chemisorption probability at sample temperatures 300÷500K.•Decrease of H concentration above 450 K is likely a result of H2 desorption.
Secondary ion mass spectrometry is a powerful analytical tool that offers great capabilities for studying hydrogen interaction with metallic materials. Yet its utilization for the in situ studies of hydrogen interaction with a sample has not been well established. In this research we study the influence of hydrogen partial pressure (5 × 10−9 – 5 × 10−5 Torr) in the sample chamber, the sample temperature (305–900K), and primary ion current density on the emission intensity of various secondary ions for the hydrogen-storage TiFe alloy sample bombarded with 12 or 20 keV Ar+ primary ions. Presence of chemisorbed hydrogen on the alloy surface results in the presence of a variety of positive and negative hydrogen-containing secondary ions in mass spectra. Analysis of the influence of the varied experimental parameters has shown that the secondary ion yield changes reflect only changes of hydrogen concentration regardless of which varied parameter induced a concentration change. The yield dependences on concentration in general are different for different ions and tend to be more substantial for the ions containing a larger number of hydrogen atoms. The ions containing one hydrogen atom have similar and likely linear yield dependences when the concentration is low. At higher concentrations, the yield dependences for these ions diverge: their relation to concentration is discussed. For not hydrogen-containing secondary ions, hydrogen saturation of the surface resulted in an 80-400% increase of the yields of Ti+ and Ti-containing positive secondary ions, no yield change for other positive ions, and 2–3-times decrease of yields of negative ions. As for hydrogen interaction processes with the alloy surface, the obtained dependence of the ion yields only on hydrogen concentration indicates that the alloy surface is rather homogeneous i.e. without large parts that have different characteristics of interaction with hydrogen and different ratios of secondary ion yields. The results of the sample temperature influence indicate that the chemisorption probability of hydrogen molecules is temperature independent at least in the ∼300-500 K range. The substantial decrease in concentration at temperatures above 450 K is a result of associative desorption of hydrogen, although a possible contribution of other processes is not excluded by the presented results.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The role and properties of lower hybrid waves in the ion diffusion region and magnetospheric inflow region of asymmetric reconnection are investigated using the Magnetospheric Multiscale (MMS) ...mission. Two distinct groups of lower hybrid waves are observed in the ion diffusion region and magnetospheric inflow region, which have distinct properties and propagate in opposite directions along the magnetopause. One group develops near the ion edge in the magnetospheric inflow, where magnetosheath ions enter the magnetosphere through the finite gyroradius effect and are driven by the ion‐ion cross‐field instability due to the interaction between the magnetosheath ions and cold magnetospheric ions. This leads to heating of the cold magnetospheric ions. The second group develops at the sharpest density gradient, where the Hall electric field is observed and is driven by the lower hybrid drift instability. These drift waves produce cross‐field particle diffusion, enabling magnetosheath electrons to enter the magnetospheric inflow region thereby broadening the density gradient in the ion diffusion region.
Key Points
Two groups of lower hybrid waves are observed in the ion diffusion and magnetospheric inflow regions
In the magnetospheric inflow region lower hybrid waves develop when cold magnetospheric ions are present and can heat cold ions
In the diffusion region lower hybrid waves develop at the density gradient and can cause cross‐field particle diffusion
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Natural polymers with abundant side functionalities are emerging as a promising binder for high‐capacity yet large‐volume‐change silicon anodes with a strong and reversible supramolecular interaction ...that originates from secondary bonding. However, the supramolecular network solely based on hydrogen bonding is relatively vulnerable to repeated deformation and has an insufficient diffusivity of lithium ions. Herein, reported is a facile but efficient way of incorporating the natural polymers with an ionically conductive crosslinker, which can construct a robust network for silicon anodes. The boronic acid in the crosslinker spontaneously reacts with natural polymers to generate boronic esters at room temperature without any kind of triggers, which gives a strong and dynamic covalent bonding to the supramolecular network. The other component in the crosslinker, polyethylene oxide, contributes to the enhanced ionic conductivity of polymers, leading to outstanding rate performances even at a high mass loading of silicon nanoparticles (>2 mg cm−2). The small portion of the proposed crosslinker can modulate the strength of the entire network by balancing the covalent crosslinking and self‐healing secondary interaction along with the fast lithium‐ion diffusion, thus enabling the extended operation of silicon electrodes.
An ionically conductive boronic crosslinker enables covalent crosslinking of natural polymer binders for silicon anodes through a spontaneous reaction at room temperature. The formed boronic ester enhances the mechanical durability of polymeric networks, while the polyethylene oxide group of the crosslinker improves lithium‐ion kinetics. This efficient design ensures structural integrity of silicon anodes and long‐term operation of rechargeable batteries.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
On 7 June 2021 the Juno spacecraft passed through the Ganymede magnetosphere, with a closest approach altitude of 1,046 km. The Jovian Auroral Distributions Experiment‐Ion (JADE‐I) sensor observed ...ionospheric ions, consisting of O2+, O+, H2+, H+, and H3+. These ions were outflowing, with no bi‐directional flow except possibly near the magnetopause. Relative ion densities with respect to time agree the electron density determined by the Waves instrument, but are ∼2.5 times larger. The light ions appear to be in hydrostatic equilibrium because the altitude profile is generally symmetric between inbound and outbound legs of the flyby. H3+ ions are an exception to this, with the ratio of H3+/H2+ being ∼a factor 4 lower on the outbound than the inbound leg. The heavy ions have higher densities outbound than inbound. The outflowing flux of light ions peak near closest approach, but the heavy ions peak outbound of the flyby.
Plain Language Summary
On 7 June 2021 the Juno spacecraft passed through the Ganymede magnetosphere, with a closest approach altitude of 1,046 km. During this flyby, the Jovian Auroral Distributions Experiment‐Ion (JADE‐I) sensor observed ions flowing out from the ionosphere. The JADE‐I observations are the first direct measurement of the composition of the ionospheric ions. This is an important measurement since there is currently not consensus of the composition. These ionospheric ions consist of O2+, O+, H2+, H+, and H3+. The different species have different altitude profiles. The light ions altitude profile is generally symmetric between inbound and outbound legs of the flyby. H3+ ions are an exception to this, with the ratio of H3+/H2+ being ∼a factor 4 lower on the outbound than the inbound leg. The heavy ions have higher densities outbound than inbound.
Key Points
First in situ, ion composition observations of Ganymede’s outflowing ionosphere
Low energy ions consist of O2+, O+, H2+, H+, and H3+
Light ions and heavy have different altitude profiles and spatial profiles
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
We present a statistical study of nose‐like structures observed in energetic hydrogen, helium, and oxygen ions near the inner edge of the plasma sheet. Nose structures are spectral features named ...after the characteristic shapes of energy bands or gaps in the energy‐time spectrograms of in situ measured ion fluxes. Using 22 months of observations from the Helium Oxygen Proton Electron instrument onboard Van Allen Probe A, we determine the number of noses observed, and the minimum L shell reached and energy of each nose on each pass through the inner magnetosphere. We find that multiple noses occur more frequently in heavy ions than in H+ and are most often observed during quiet times. The heavy‐ion noses penetrate to lower L shells than H+ noses, and there is an energy‐magnetic local time (MLT) dependence in the nose locations and energies that is similar for all species. The observations are interpreted by using a steady state model of ion drift in the inner magnetosphere. The model is able to explain the energy and MLT dependence of the different types of nose structures. Different ion charge‐exchange lifetimes are the main cause for the deeper penetration of heavy‐ion noses. The species dependence and preferred geomagnetic conditions of multiple‐nose events indicate that they must be on long drift paths, leading to strong charge‐exchange effects. The results provide important insight into the spatial distribution, species dependence, and geomagnetic conditions under which nose structures occur.
Key Points
A statistical study of H+, He+, and O+ nose structures observed by the ECT‐HOPE mass spectrometer on board the Van Allen Probes is performed
Multiple‐nose structures are preferentially observed in heavy ions and during low activity levels
The dependence of nose structures on energy, L, and MLT is generally consistent with a simple model of ion drift and charge‐exchange losses
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Lithium has literally been everywhere forever, since it is one of the three elements created in the Big Bang. Lithium concentration in rocks, soil, and fresh water is highly variable from place to ...place, and has varied widely in specific regions over evolutionary and geologic time. The biological effects of lithium are many and varied. Based on experiments in which animals are deprived of lithium, lithium is an essential nutrient. At the other extreme, at lithium ingestion sufficient to raise blood concentration significantly over 1 mM/, lithium is acutely toxic. There is no consensus regarding optimum levels of lithium intake for populations or individuals—with the single exception that lithium is a generally accepted first-line therapy for bipolar disorder, and specific dosage guidelines for sufferers of that condition are generally agreed on. Epidemiological evidence correlating various markers of social dysfunction and disease vs. lithium level in drinking water suggest benefits of moderately elevated lithium compared to average levels of lithium intake. In contrast to other biologically significant ions, lithium is unusual in not having its concentration in fluids of multicellular animals closely regulated. For hydrogen ions, sodium ions, potassium ions, calcium ions, chloride ions, and magnesium ions, blood and extracellular fluid concentrations are closely and necessarily regulated by systems of highly selective channels, and primary and secondary active transporters. Lithium, while having strong biological activity, is tolerated over body fluid concentrations ranging over many orders of magnitude. The lack of biological regulation of lithium appears due to lack of lithium-specific binding sites and selectivity filters. Rather lithium exerts its myriad physiological and biochemical effects by competing for macromolecular sites that are relatively specific for other cations, most especially for sodium and magnesium. This review will consider what is known about the nature of this competition and suggest using and extending this knowledge towards the goal of a unified understanding of lithium in biology and the application of that understanding in medicine and nutrition.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In this study, the influence of polymer water content on ion diffusion coefficients of alkali metal chlorides (LiCl, NaCl, and KCl) in cross-linked poly(ethylene glycol) diacrylate (XLPEGDA) ...hydrogels was investigated. This research is part of a broader effort to understand the fundamentals of water and ion transport in hydrated polymers. Salt diffusion coefficients were calculated from salt permeability and sorption measurements. XLPEGDA hydrogels were synthesized with three different water contents (50, 67, and 93 g water/g dry polymer). The diffusion coefficients of alkali metal chlorides in XLPEGDA polymers increased as water content increased. The Mackie and Meares model, which accounts for polymer chain obstruction (i.e., tortuosity) effects on salt diffusion in hydrated polymers, was used to interpret salt diffusion coefficients. The general trend of the experimentally determined salt diffusion coefficients in these polymers is consistent with the model. Individual ion diffusion coefficients in the samples were obtained by combining salt permeability/sorption data with ionic conductivity results. The chloride ion diffusion coefficients were similar for all salts. The relative order of alkali metal ion diffusion coefficients in these polymers was different from that in aqueous solution (i.e., DK+s>DNa+s>DLi+s). Moreover, this order changes as polymer water content varies, suggesting that alkali metal chloride diffusion behavior in XLPEGDA polymers is influenced by both ion hydration and polymer-ion specific interactions.
Display omitted
•Interactions between ions and polymer chains influence ion diffusion behavior.•The relative order of salt diffusion coefficients varies depending on polymer water content.•Ionic conductivity was combined with salt permeability/sorption data to obtain single ion diffusion coefficients.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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