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All sourcesNASA NTRSDOE OSTI
NASA NTRS2014

Magnetosheath Filamentary Structures Formed by Ion Acceleration at the Quasi-Parallel Bow Shock

Results from 2.5-D electromagnetic hybrid simulations show the formation of field-aligned, filamentary plasma structures in the magnetosheath. They begin at the quasi-parallel bow shock and extend far into the magnetosheath. These structures exhibit anticorrelated, spatial oscillations in plasma density and ion temperature. Closer to the bow shock, magnetic field variations associated with density and temperature oscillations may also be present. Magnetosheath filamentary structures (MFS) form primarily in the quasi-parallel sheath; however, they may extend to the quasi-perpendicular magnetosheath. They occur over a wide range of solar wind Alfvénic Mach numbers and interplanetary magnetic field directions. At lower Mach numbers with lower levels of magnetosheath turbulence, MFS remain highly coherent over large distances. At higher Mach numbers, magnetosheath turbulence decreases the level of coherence. Magnetosheath filamentary structures result from localized ion acceleration at the quasi-parallel bow shock and the injection of energetic ions into the magnetosheath. The localized nature of ion acceleration is tied to the generation of fast magnetosonic waves at and upstream of the quasi-parallel shock. The increased pressure in flux tubes containing the shock accelerated ions results in the depletion of the thermal plasma in these flux tubes and the enhancement of density in flux tubes void of energetic ions. This results in the observed anticorrelation between ion temperature and plasma density.

magnetosheath↗
NASA NTRS2016

Silver Ion Biocide Delivery System for Water Disinfection

U.S. space exploration missions have long considered returning to the Moon and exploration of Mars that challenge life support systems. For these long duration missions, there is interest in replacing the iodine water treatment system with ionic silver, a proven biocide. For long duration exploration missions, it is imperative that an effective biocide be used that prevents microbial growth, biofilm formation, and microbially induced corrosion in the water storage and distribution systems while minimizing logistical supply requirements associated with the biocide delivery system. Two biocide delivery systems have been developed that electrochemically produce silver ions for disinfecting water throughout the water storage and distribution system. One system uses a newly developed hybrid micro-filtration and ion-exchange membrane to produce an abundance of silver ions at the 1000 ppb level upstream in the water distribution system to prevent biofilm growth. This is followed by a downstream collection module that electrochemically removes these silver ions before the water is discharged. Another approach uses a membraneless reactor to produce a 1000 ppb silver ion concentration level that also has a mechanically driven electrode cleaning mechanism that removes oxide films ensuring long life operation. By maintaining a sufficiently high level of silver ions throughout the water storage and distribution system, biofilm formation is suppressed. This approach overcomes present concerns where spurious silver deposition occurs on the container and flow line surfaces thus lowering the silver ion concentration to unsatisfactory disinfection levels.

Slote, Benjamin M.↗
NASA NTRS2015

The Importance of the Cathode Plume and Its Interactions with the Ion Beam in Numerical Simulations of Hall Thrusters

Hall2De is a first-principles, 2-D axisymmetric code that solves the equations of motion for ions, electrons, and neutrals on a magnetic-field-aligned grid. The computational domain downstream of the acceleration channel exit plane is large enough to include self-consistently the cathode boundary. In this paper, we present results from numerical simulations of the H6 laboratory thruster with an internally mounted cathode, with the aim of highlighting the importance of properly accounting for the interactions between the ion beam and cathode plume. The anomalous transport of electrons across magnetic field lines in Hall2De is modelled using an anomalous collision frequency, νanom, yielding νanom approximately equal to omega ce (i.e., the electron cyclotron frequency) in the plume. We first show that restricting the anomalous collision frequency to only regions where the current density of ions is large does not alter the plasma discharge in the Hall thruster as long as the interaction between the ion beam and the cathode plume is captured properly in the computational domain. This implies that the boundary conditions must be placed sufficiently far as to not interfere with the electron transport in this region. These simulation results suggest that electron transport across magnetic field lines occurs largely inside the beam and may be driven by the interactions between beam ions and electrons. A second finding that puts in relevance the importance of including the cathode plume in numerical simulations is on the significance of accounting for the ion acoustic turbulence (IAT), now known to occur in the vicinity of the cathode exit. We have included in the Hall2De simulations a model of the IAT-driven anomalous collision frequency based on Sagdeev's model for saturation of the ion-acoustic instability. This implementation has allowed us to achieve excellent agreement with experimental measurements in the near plume obtained during the operation of the H6 thruster at nominal conditions (300V, 20A) and chamber background pressure of approximately 1.5 x 10(exp -5) Torr. In addition, the numerical results obtained with the latter approach exhibit less sensitivity to background pressure than previous attempts at explaining the features of the plasma properties in the near plume.

Lopez Ortega, Alejandro↗
NASA NTRS2019

Waste Water Brine Purification through Electrodialysis Ion Exchange

Reutilizing resources onboard the International Space Station (ISS) and for future deep space missions are critical for mission longevity and sustainability. Waste water brine produced from water recovery systems contain chemical species that could be processed into a potential fertilizer for future plant systems.Fertilizer production can be achieved through a process called electrodialysis ion exchange. Waste water containing inorganic salt components are fed through a series of ion exchange membranes to produce fertilizer (a phosphate rich stream), electrolysis-grade water, and other useful commodities.A test bed was constructed to conduct controlled experiments and an experimental design procedure developed to determine the feasibility of the process. Conductivity and pH probes were utilized to determine the ion concentration in each of the product streams, along with ion chromatography (IC) to define the exact concentration of each ion in every stream throughout the experiment. This is crucial in order to convey the effectiveness of ion removal from the incoming waste water stream.The waste water and electrolyte streams were prepared in the lab prior to experimentation. Additionally, the ion exchange membrane configurations were developed and Opto 22 data analysis software incorporated to conduct measurements in real time.Ions successfully diffused across their respective membranes into the concentrate, acid, and base streams. This resulted in pure water, a phosphate rich stream, and a separate anion/hydrogen and cation/hydroxide stream.

Hancock, Matthew L.↗
NASA NTRS2023

Foreshock Ion Motion Across Discontinuities: Formation of Foreshock Transients

In the ion foreshock, hot flow anomalies (HFAs) and foreshock bubbles (FBs) are two types of foreshock transients that have the strongest fluctuations, which can disturb the magnetosphere-ionosphere system and increase shock acceleration efficiency. They form due to interaction between the foreshock ions and solar wind discontinuities: the direction of the foreshock ion-driven current and whether it decreases or increases the magnetic field strength behind the discontinuity determine whether the transient's formation can be promoted or suppressed. Thus, to predict the HFA and FB formation and forecast their space weather effects, it is necessary to predict the foreshock ion-driven current direction. In this study, we derive analytical equations of foreshock ion velocities within discontinuities to estimate foreshock ion-driven current direction, which provides a quantitative criterion of HFA and FB formation. To validate the criterion, we use Acceleration Reconnection Turbulence & Electrodynamics of Moon's Interaction with the Sun to observe pristine solar wind discontinuities and calculate discontinuity parameters. We use Magnetospheric Multiscale to observe the foreshock ion motion around the discontinuities and show that the data support our model. This study is another step toward a predictive model of HFA and FB formation so that we can forecast their space weather effects at Earth using solar wind observations at lunar orbit or L1.

Terry Z. Liu↗
NASA NTRS2023

First results from the Solar Orbiter Heavy Ion Sensor

Aims . Solar Orbiter launched in February 2020 with the goal of revealing the connections between the Sun’s interior, atmosphere, and the heliosphere. The Solar Orbiter Heavy Ion Sensor (HIS) is a time-of-flight ion mass spectrometer dedicated to measuring heavy ions in the solar wind. Methods . We present an overview of the first measurements of heavy ion composition from HIS, reviewing the methods used to transform the spectra obtained on board into scientific data products and examining two solar wind case studies as well as the statistical properties of the heavy ion composition observed by HIS. We also carried out a comparison with prior measurements of heavy ions at L1. Results . The HIS data set provides the first mass- and charge-resolved heavy ion measurements in the inner heliosphere. Conclusions . These high temporal resolution data have the potential to transform our understanding of the connections between the solar wind and its origin at the Sun, as well as the interaction between the solar wind and the environment around planets, comets, and in the interstellar medium.

solar wind↗
NASA NTRSDate not supplied

Separation of isobaric Amino Acids and Small Molecule Metabolites Using Multipass Ion Mobility Analysis

Amino acids along with small molecule metabolites are important biomarkers for the study and detection of diseases that are initially analyzed in untargeted omics fashion. Amino acids and many metabolites are isomeric, and their specific form can have a significant impact on biological function. Chromatographic separation of isomers is challenging, and they cannot be resolved by mass spectrometry alone. Ion mobility is a technique that allows the separation of ions based on their size, shape, and charge. Here we present the results of the separation of isobaric amino acids and small molecule metabolites using a system that allows for multi-pass ion mobility separation which, in turn, enhances the ion mobility resolution of the separation. Amino acid standards and small molecule metabolites commercially available were infused directly into a SELECT SERIES™ Cyclic™ IMS system. Solutions of individual and mixture of the isobaric species were used and the mobility conditions were optimized for multiple passes for each corresponding set of isobaric species. Both ionization polarities and various solvent adducts were tested to provide the best signal intensity and separation. Amino acids such as leucine and isoleucine have previously been separated with ion mobility in a system with lower ion mobility resolution (SYNAPT™ G2 mass spectrometer) rendering about 90% of valley and mobility resolution of around 40 Ω/ΔΩ. With the enhanced ion mobility resolution using the cyclic IMS technique we have obtained almost complete separation of those amino acids rendering a valley of about 10% after 15 passes. For this case, the mobility resolution is around 250 Ω/ΔΩ. Another example is the separation of glucose-6-phosphate from glucose-1-phosphate, and fructose-6phosphate which were separated after 10 passes. For this case, the mobility resolution is around 205 Ω/ΔΩ.

Hernando J Olivos↗
NASA NTRS1987

The locations and amounts of endogenous ions and elements in the cap and elongating zone of horizontally oriented roots of Zea mays L.: an electron-probe EDS study

We used quantitative electron-probe energy-dispersive x-ray microanalysis to localize endogenous Na, Cl, K, P, S, Mg and Ca in cryofixed and freeze-dried cryosections of the cap (i.e. the putative site of graviperception) and elongating zone (i.e. site of gravicurvature) of horizontally oriented roots of Zea mays. Ca, Na, Cl, K and Mg accumulate along the lower side of caps of horizontally oriented roots. The most dramatic asymmetries of these ions occur in the apoplast, especially the mucilage. We could not detect any significant differences in the concentrations of these ions in the central cytoplasm of columella cells along the upper and lower sides of caps of horizontally-oriented roots. However, the increased amounts of Na, Cl, K and Mg in the longitudinal walls of columella cells along the lower side of the cap suggest that these ions may move down through the columella tissue of horizontally-oriented roots. Ca also accumulates (largely in the mucilage) along the lower side of the elongating zone of horizontally-oriented roots, while Na, P, Cl and K tend to accumulate along the upper side of the elongating zone. Of these ions, only K increases in concentration in the cytoplasm and longitudinal walls of cortical cells in the upper vs lower sides of the elongating zone. These results indicate that (1) gravity-induced asymmetries of ions differ significantly in the cap and elongating zone of graviresponding roots, (2) Ca accumulates along the lower side of the cap and elongating zone of graviresponding roots, (3) increased growth of the upper side of the elongating zone of horizontally-oriented roots correlates positively with increased amounts of K in the cytoplasm and longitudinal walls of cortical cells, and (4) the apoplast (especially the mucilage) may be an important component of the pathway via which ions move in graviresponding rots of Zea mays. These results are discussed relative to mechanisms for graviperception and gravicurvature of roots.

NASA Program Space Biology↗
NASA NTRS1993

Ion mobility spectrometry of hydrazine, monomethylhydrazine, and ammonia in air with 5-nonanone reagent gas

Hydrazine (HZ) and monomethylhydrazine (MMH) in air were monitored continuously using a hand-held ion mobility spectrometer equipped with membrane inlet, 63Ni ion source, acetone reagent gas, and ambient temperature drift tube. Response characteristics included detection limit, 6 ppb; linear range, 10-600 ppb; saturated response, >2 ppm; and stable response after 15-30 min. Ammonia interfered in hydrazines detection through a product ion with the same drift time as that for MMH and HZ. Acetone reagent gas was replaced with 5-nonanone to alter drift times of product ions and separate ammonia from MMH and HZ. Patterns in mobility spectra, ion identifications from mass spectra, and fragmentation cross-sections from collisional-induced dissociations suggest that drift times are governed by ion-cluster equilibria in the drift region of the mobility spectrometer. Practical aspects including calibration, stability, and reproducibility are reported from the use of a hand-held mobility spectrometer on the space shuttle Atlantis during mission STS-37.

Flight Experiment↗
NASA NTRS2003

Transmission measurement based on STM observation to detect the penetration depth of low-energy heavy ions in botanic samples

The penetration depth of low-energy heavy ions in botanic samples was detected with a new transmission measurement. In the measurement, highly oriented pyrolytic graphite (HOPG) pieces were placed behind the botanic samples with certain thickness. During the irradiation of heavy ions with energy of tens of keV, the energetic particles transmitted from those samples were received by the HOPG pieces. After irradiation, scanning tunneling microscope (STM) was applied to observe protrusion-like damage induced by these transmitted ions on the surface of the HOPG. The statistical average number density of protrusions and the minimum transmission rate of the low-energy heavy ions can be obtained. The detection efficiency of the new method for low-energy heavy ions was about 0.1-1 and the background in the measurement can be reduced to as low as 1.0 x 10(8) protrusions/cm2. With this method, the penetration depth of the energetic particles was detected to be no less than 60 micrometers in kidney bean slices when the slices were irradiated by 100 keVAr+ ion at the fluence of 5 x 10(16) ions/cm2. c2002 Elsevier Science Ltd. All rights reserved.

DNA Damage↗
NASA NTRS2004

DNA fragmentation induced by Fe ions in human cells: shielding influence on spatially correlated damage

Outside the magnetic field of the Earth, high energy heavy ions constitute a relevant part of the biologically significant dose to astronauts during the very long travels through space. The typical pattern of energy deposition in the matter by heavy ions on the microscopic scale is believed to produce spatially correlated damage in the DNA which is critical for radiobiological effects. We have investigated the influence of a lucite shielding on the initial production of very small DNA fragments in human fibroblasts irradiated with 1 GeV/u iron (Fe) ions. We also used gamma rays as reference radiation. Our results show: (1) a lower effect per incident ion when the shielding is used; (2) an higher DNA Double Strand Breaks (DSB) induction by Fe ions than by gamma rays in the size range 1-23 kbp; (3) a non-random DNA DSB induction by Fe ions. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

NASA Discipline Radiation Health↗
NASA NTRS2007

Performance of Low Temperature Electrolytes in Experimental and Prototype Li-Ion Cells

Due to their attractive properties and proven success, Li-ion batteries have become identified as the battery chemistry of choice for a number of future NASA missions. A number of these applications would be greatly benefited by improved performance of Li-ion technology over a wider operating temperature range, especially at low temperatures, such as future ESMD missions. In many cases, these technology improvements may be mission enabling, and at the very least mission enhancing. In addition to aerospace applications, the DoE has interest in developing advanced Li-ion batteries that can operate over a wide temperature range to enable terrestrial HEV applications. Thus, our focus at JPL in recent years has been to extend the operating temperature range of Li-ion batteries, especially at low temperatures. To accomplish this, the main focus of the research has been devoted to developing improved lithium-ion conducting electrolytes. In the present paper, we would like to present some of the results we have obtained with ethylene carbonate-based electrolytes optimized for low temperature in experimental MCMB-LiNixCo1_x0 2 cells. In addition to obtaining discharge and charge rate performance data at various temperatures, electrochemical measurements were performed on individual electrodes (made possible by the incorporation of Li reference electrodes), including EIS, linear polarization and Tafel polarization measurements. The combination of techniques enables the elucidation of various trends associated with electrolyte composition. In addition to investigating the behavior in experimental cells, the performance of many promising low temperature electrolytes was demonstrated in large capacity, aerospace quality Li-ion prototype cells. These cells were subjected to a number of performance tests, including discharge rate characterization, charge rate characterization, cycle life performance at various temperatures, and power characterization tests.

Li-ion batteries↗
NASA NTRS2017

International Space Station Lithium-Ion Battery Start-Up and Cycling

The International Space Station (ISS) primary Electric Power System (EPS) was originally designed to use Nickel-Hydrogen (Ni-H2) batteries to store electrical energy. The electricity for the ISS is generated by its solar arrays, which charge batteries during insolation for subsequent discharge during eclipse. The Ni-H2 batteries were designed to operate at a 35 depth of discharge (DOD) maximum during normal operation in a Low Earth Orbit. In 2010, the ISS Program began the development of Lithium-Ion (Li-Ion) batteries to replace Ni-H2 batteries approaching the end of their useful life and concurrently funded a Li-Ion ORU (Orbital Replacement Unit) and cell life testing project. The first set of 6 Li-ion battery replacements was launched in December 2016 and deployed in January 2017. This paper will discuss the Li-ion battery on-orbit cycling and the status of the Li-Ion cell and ORU life cycle testing.

International Space Station↗
NASA NTRS1994

Segmented Ion Engine Plume Characteristics

Preliminary evaluation of the segmented ion thruster (SIT) ion beam characteristics was performed by measuring the two dimensional ion current density distribution at four axial locations downstream from the thruster. Current density profiles were measured with the concurrent operation of multiple ion sources. Preliminary assessments regarding symmetry of the plume, characterization of plume development as a function of axial position, and the interactions of multiple simultaneously operating ion sources were conducted. A numerical integration scheme was applied to the acquired data to determine the total beam current. A qualitative analysis of the downstream development of the ion beam was conducted. Most of the data acquired so far has been on somewhat of a trial basis and extensive testing is scheduled to resume in August 1994.

ion↗
NASA NTRS2022

Lithium-ion Battery Strain Gauge Monitoring and Depth of Discharge Estimation

Lithium-ion battery diagnostics and prognostics rely on measurements of electrical impedance, capacity, and voltage to infer the internal state of the battery. Mechanical changes to the cell structure represent an additional measure of the battery’s state because these changes are related to the overall battery health. As lithium-ion batteries are charged and discharged, lithium ions are inserted or removed from the anode and cathode, a process called intercalation and de-intercalation. As lithium ions intercalate and de-intercalate, they can cause changes to the lattice of the electrode particles, resulting in volumetric changes. These volumetric changes cause mechanical stresses and strains on the lithium-ion battery electrodes, and subsequently, the whole cell’s thickness varies as it is charged and discharged. This paper presents a study on the use of surface-mounted strain gauges for in-situ measurement of structural changes to lithium-ion batteries, along with a characterization of the unit-to-unit differences in strain response. A neural network modeling structure is then used to predict the battery’s depth of discharge under dynamic discharge conditions.

Lithium-ion batteries, depth of discharge, strain ↗
NASA NTRS1964

New apparatus increases ion beam power density

To increase ion engine or rocket power, an ion source and emitter, an ion beam focusing electrode, and an ion accelerator are incorporated into the system. In operation the space charge surrounding the ion emitter decreases, the ion beam density accelerates, and engine power increases.

Baldwin, L. V.↗
NASA NTRS1971

Ion-wave current instabilities and anomalous resistivity.

A theory of ion-wave current instabilities which takes into account, in a self-consistent manner, the inhomogeneities generated by field-aligned currents in a collisionless plasma is presented. Diamagnetic current associated with the current-produced density gradient is included in the distribution. The theory predicts that for a given frequency, the current threshold for ion-wave current instabilities is, in general, much below the threshold of ion acoustic instability in a uniform plasma as given by Fried and Gould. The current threshold is essentially zero in the limit when the ion Landau damping effect is negligible, or equivalently, the ion-wave current instabilities are absolute if there are no limitations on the wavelength. This is true even in the absence of externally applied density gradients in contrast to Kadomtsev's drift-wave results. For dimensions of interest in laboratory plasmas, the predicted linear growth rate increases with increasing longitudinal wavelength and with decreasing wavelength parallel to the diamagnetic current. Under the conditions of an experiment on anomalous resistivity (the dimensions but not the geometry of the machine have been considered), there is good agreement between the predicted onset of ion-wave current instabilities and the experimental data on the onset of anomalous resistivity.

Kan, J. R.↗
NASA NTRS1973

Nighttime ion composition measurements at the geomagnetic equator

Two ion composition profiles, representative of the nighttime equatorial ionosphere between 90 km and 300 km, are presented. These profiles were obtained by two rocket-borne ion mass spectrometers on a single night for solar zenith angles of 112 deg and 165 deg. For both flights, the principal ion above 200 km is O(+). The downward drift of the atomic ions O(+) and N(+), coinciding with the postsunset lowering of the F2 peak, is observed through an enhancement of the density of O(+) at altitudes above 200 km and N(+) above 240 km. Below the drift region, O(+) and N(+) are observed in concentrations larger than expected. The NO(+) altitude distribution retains its shape throughout the night, and below 210 km, is the principal ion. The behavior of O2(+) can be explained by the O(+), electron density and theoretical neutral nitric oxide concentrations. Light metallic ions, including Mg(+), Na(+), and possibly Si(+), are observed to altitudes approaching 300 km and are affected by vertical drift.

Goldberg, R. A.↗