Search NASA⌕ Search

SEARCH · Search NASA

Results for “plasma instrumentation”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records

A new innovative instrument for space plasma instrumentation

The Faraday Ring Ammeter was the subject of this grant for a new innovative instrument for space plasma instrumentation. This report summarizes our progress in this work. Briefly, we have conducted an intensive series of experiments and trials over three years, testing some five configurations of the instrument to measure currents, resulting in two Ph.D. theses, supported by this grant, and two flight configurations of the instrument. The first flight would have been on a NASA-Air Force collaborative sounding rocket, but was not flown because of instrumental difficulties. The second has been successfully integrated on the NASA Auroral Turbulence payload which is to be launched in February, 1994.

Torbert, Roy B.↗

The Low Altitude Plasma Instrument /LAPI/

The Low Altitude Plasma Instrument on the Dynamics Explorer-B spacecraft provides high resolution velocity space measurements of positive ions and electrons from 5 eV to 32 keV and a monitor of electrons with energies above 35 keV. It consists of an array of 15 parabolic electrostatic analyzers spanning 180 deg in angle and two Geiger-Mueller counters mounted on a one-degree of freedom scan platform. The platform is controlled by a magnetometer that allows placement of the array to selected angles with respect to the magnetic field. Each parabolic analyzer simultaneously measures electrons and positive ions. The temporal resolution and energy range of the measurements and the detector complement to be sampled are programmable by ground command

Winningham, J. D.↗

The plasma instrumentation for the Galileo Mission

The Galileo Mission's plasma instrumentation package encompasses a nested set of four spherical-plate electrostatic analyzers and three miniature magnetic mass spectrometers which identify the composition of the positive ion plasmas; the spectrometers' energy range is species-dependent. Two instrument microprocessors allow in-flight implementation of operational modes by ground command that are tailored for such specific regimes as the magnetosheath and the plasma sheet of the environs of Jupiter. Observational objectives include field-aligned currents, 3D ion bulk flows, Galilean satellite pickup ions, and the spatial distributions of plasmas.

Frank, L. A.↗

Enhanced ion outflows measured by the DE 1 high altitude plasma instrument in the dayside plasmasphere during the recovery phase

Ion flow velocities both parallel and perpendicular to the magnetic field, and including the effects of spacecraft charging and spacecraft velocity, have been measured during the recovery phase of two large magnetic storms on October 14 and 21 of 1981. These measurements were made both inside and outside the plasmasphere and indicate unreported yet substantial outflows of ions within the dayside plasmasphere (October 14). Combined data from instruments on board the Dynamics Explorer satellite, including the high altitude plasma instrument, the energetic ion composition spectrometer, the retarding ion mass spectrometer, and the plasma wave instrument, indicate that these ions are most likely dominantly O(+) at energies at least as low as 5 eV. The nightside pass (October 21), which occurred during the recovery phase of a similar storm, showed no plasmaspheric outflows. The results indicate that a large contribution to the outflux into the dayside plasmasphere during the recovery period is due to E greater than 5 eV ions.

Menietti, J. D.↗

High-Altitude Plasma Instrument for Dynamics Explorer-A

The Dynamics Explorer A High-Altitude Plasma Instrument (HAPI) will make differential measurements of the velocity-space distributions of electrons and positive ions over the energy/charge range of 5 eV to 32 keV. Five identical analyzers, each making simultaneous measurements of electrons and positive ions at 64 possible energy levels, will have viewing angles of 45, 78, 90, 102, and 135 deg relative to the spacecraft spin axis. The HAPI data will contribute to the overall Dynamics Explorer science objectives, particularly by providing information on the hot-plasma effects of the coupling of energy, mass, and momentum within the earth's atmosphere, ionosphere, and magnetosphere.

Burch, J. L.↗

Two Dual Ion Spectrometer Flight Units of the Fast Plasma Instrument Suite (FPI) for the Magnetospheric Multiscale Mission (MMS)

Two Dual Ion Spectrometer flight units of the Fast Plasma Instrument Suite (FPI) for the Magnetospheric Multiscale Mission (MMS) have returned to MSFC for flight testing. Anticipated to begin on June 30, tests will ensue in the Low Energy Electron and Ion Facility of the Heliophysics and Planetary Science Office (ZP13), managed by Dr. Victoria Coffey of the Natural Environments Branch of the Engineering Directorate (EV44). The MMS mission consists of four identical spacecraft, whose purpose is to study magnetic reconnection in the boundary regions of Earth's magnetosphere.

Adams, Mitzi↗

Fast Plasma Instrument for MMS: Data Compression Simulation Results

Magnetospheric Multiscale (MMS) mission will study small-scale reconnection structures and their rapid motions from closely spaced platforms using instruments capable of high angular, energy, and time resolution measurements. To meet these requirements, the Fast Plasma Instrument (FPI) consists of eight (8) identical half top-hat electron sensors and eights (8) identical ion sensors and an Instrument Data Processing Unit (IDPU). The sensors (electron or ion) are grouped into pairs whose 6 deg x 180 deg fields-of-view (FOV) are set 90 deg apart. Each sensor is equipped with electrostatic aperture steering to allow the sensor to scan a 45 deg x 180 deg fan about its nominal viewing (0 deg deflection) direction. Each pair of sensors, known as the Dual Electron Spectrometer (DES) and the Dual Ion Spectrometer (DIS), occupies a quadrant on the MMS spacecraft and the combination of the eight electron/ion sensors, employing aperture steering, image the full-sky every 30-ms (electrons) and 150-ms (ions), respectively. To probe the results in the DES complement of a given spacecraft generating 6.5-Mbs(exp -1) of electron data while the DIS generates 1.1-Mbs(exp -1) of ion data yielding an FPI total data rate of 6.6-MBs(exp -1). The FPI electron/ion data is collected by the IDPU then transmitted to the Central Data Instrument Processor (CIDP) on the spacecraft for science interest ranking. Only data sequences that contain the greatest amount of temporal/spatial structure will be intelligently down-linked by the spacecraft. Currently, the FPI data rate allocation to the CIDP is 1.5-Mbs(exp -1). Consequently, the FPI-IDPU must employ data/image compression to meet this CIDP telemetry allocation. Here, we present simulations of the CCSDS 122.0-B-1 algorithm-based compression of the FPI-DES electron data. Compression analysis is based upon a seed of re-processed Cluster/PEACE electron measurements. Topics to be discussed include: review of compression algorithm; data quality; data formatting/organization; and, implications for data/matrix pruning. To conclude a presentation of the base-lined FPI data compression approach is provided.

Barrie, A.↗

Fast Plasma Instrument for MMS: Simulation Results

Magnetospheric Multiscale (MMS) mission will study small-scale reconnection structures and their rapid motions from closely spaced platforms using instruments capable of high angular, energy, and time resolution measurements. The Dual Electron Spectrometer (DES) of the Fast Plasma Instrument (FPI) for MMS meets these demanding requirements by acquiring the electron velocity distribution functions (VDFs) for the full sky with high-resolution angular measurements every 30 ms. This will provide unprecedented access to electron scale dynamics within the reconnection diffusion region. The DES consists of eight half-top-hat energy analyzers. Each analyzer has a 6 deg. x 11.25 deg. Full-sky coverage is achieved by electrostatically stepping the FOV of each of the eight sensors through four discrete deflection look directions. Data compression and burst memory management will provide approximately 30 minutes of high time resolution data during each orbit of the four MMS spacecraft. Each spacecraft will intelligently downlink the data sequences that contain the greatest amount of temporal structure. Here we present the results of a simulation of the DES analyzer measurements, data compression and decompression, as well as ground-based analysis using as a seed re-processed Cluster/PEACE electron measurements. The Cluster/PEACE electron measurements have been reprocessed through virtual DES analyzers with their proper geometrical, energy, and timing scale factors and re-mapped via interpolation to the DES angular and energy phase-space sampling measurements. The results of the simulated DES measurements are analyzed and the full moments of the simulated VDFs are compared with those obtained from the Cluster/PEACE spectrometer using a standard quadrature moment, a newly implemented spectral spherical harmonic method, and a singular value decomposition method. Our preliminary moment calculations show a remarkable agreement within the uncertainties of the measurements, with the results obtained by the Cluster/PEACE electron spectrometers. The data analyzed was selected because it represented a potential reconnection event as currently published.

Figueroa-Vinas, Adolfo↗

Comprehensive Plasma Instrumentation (CPU) for the Geotail spacecraft

Geotail was launched on 24 July 1992 as the first new spacecraft of the International Solar Terrestrial Physics Program (ISTP). A primary objective of the Geotail mission is the acquisition of particles and fields measurements in the tail region of the magnetosphere. Some of the specific scientific objectives of the Geotail mission are; (1) assessment of the relative importance of solar-wind and ionospheric sources to the plasmas of the magnetotail, (2) a search for plasmoids and flux ropes, (3) direct observation of the effects of plasma acceleration and heating in the current sheet, and (4) measurements of currents and convective flows carried by magnetotail plasmas. The Comprehensive Plasma Instrumentation (CPI) aboard the Geotail spacecraft provides observations of the charged particles that comprise the plasma populations of the magnetosphere and the solar wind. In many cases the physical processes that contribute to the flow of energy and mass through the Solar-Terrestrial plasma system can be understood only through a detailed examination and analysis of the distribution of the particle velocities in the ambient plasmas. The CPI provides detailed measurements of these distributions. It employs three plasma analyzers: (1) the Hot Plasma analyzer (CPI-HP) for hot electrons and ions found in the plasma sheet and the inner magnetosphere; (2) a Solar Wind analyzer (CPI-SW) for cool plasmas with high bulk speeds such as those found in the solar wind and magnetosheath; and (3) an Ion Composition analyzer (CPI-IC) for identification of ion species such as H(+), He(+), He(++), and O(+). Along with measurements from other fields and particles instrumentation on Geotail, the CPI measurements provide a fundamental experimental base for investigations of solar-terrestrial plasmas and fields.

Frank, Louis A.↗

The response function of modulated grid Faraday cup plasma instruments

Modulated grid Faraday cup plasma analyzers are a very useful tool for making in situ measurements of space plasmas. One of their great attributes is that their simplicity permits their angular response function to be calculated theoretically. An expression is derived for this response function by computing the trajectories of the charged particles inside the cup. The Voyager Plasma Science (PLS) experiment is used as a specific example. Two approximations to the rigorous response function useful for data analysis are discussed. The theoretical formulas were tested by multi-sensor analysis of solar wind data. The tests indicate that the formulas represent the true cup response function for all angles of incidence with a maximum error of only a few percent.

Barnett, A.↗

Response function of modulated grid Faraday cup plasma instruments

Modulated grid Faraday cup plasma analyzers are a very useful tool for making in situ measurements of space plasmas. One of their great attributes is that their simplicity permits their angular response function to be calculated theoretically. An expression is derived for this response function by computing the trajectories of the charged particles inside the cup. The Voyager plasma science experiment is used as a specific example. Two approximations to the rigorous response function useful for data analysis are discussed. Multisensor analysis of solar wind data indicates that the formulas represent the true cup response function for all angles of incidence with a maximum error of only a few percent.

Barnett, A.↗

High Altitude Plasma Instrument (HAPI) data analysis

The objectives of the Dynamics Explorer mission are to investigate the coupling of energy, mass, and momentum among the earth's magnetosphere, ionosphere, and upper atmosphere. At launch, on August 3, 1981, DE-1 was placed into an elliptical polar orbit having an apogee of 23,130 km to allow global auroral imaging and crossings of auroral field lines at altitudes of several thousand kilometers. At the same time DE-2 was placed into a polar orbit, coplanar with that of DE-1 but with a perigee altitude low enough (309 km) for neutral measurements and an apogee altitude of 1012 km. The DE-1 High Altitude Plasma Instrument (HAPI) provided data on low and medium energy electrons and ions from August 13, 1981 until December 1, 1981, when a high-voltage failure occured. Analysis of HAPI data for the time period of this contract has produced new results on the source mechanisms for electron conical distributions, particle acceleration phenomena in auroral acceleration regions, Birkeland currents throughout the nightside auroral regions, the source region for auroral kilometric radiation (AKR), and plasma injection phenomena in the polar cusp.

Burch, J. L.↗

The Polar Plasma Wave Instrument

The Plasma Wave Instrument on the Polar spacecraft is designed to provide measurements of plasma waves in the Earth's polar regions over the frequency range from 0.1 Hz to 800 kHz. Three orthogonal electric dipole antennas are used to detect electric fields, two in the spin plane and one aligned along the spacecraft spin axis. A magnetic loop antenna and a triaxial magnetic search coil antenna are used to detect magnetic fields. Signals from these antennas are processed by five receiver systems: a wideband receiver, a high-frequency waveform receiver, a low-frequency waveform receiver, two multichannel analyzers; and a pair of sweep frequency receivers. Compared to previous plasma wave instruments, the Polar plasma wave instrument has several new capabilities. These include (1) an expanded frequency range to improve coverage of both low- and high-frequency wave phenomena, (2) the ability to simultaneously capture signals from six orthogonal electric and magnetic field sensors, and (3) a digital wideband receiver with up to 8-bit resolution and sample rates as high as 249k samples s(exp -1).

Gurnett, D. A.↗

Continued reduction and analysis of data from the Dynamics Explorer Plasma Wave Instrument

The plasma wave instrument on the Dynamics Explorer 1 spacecraft provided measurements of the electric and magnetic components of plasma waves in the Earth's magnetosphere. Four receiver systems processed signals from five antennas. Sixty-seven theses, scientific papers and reports were prepared from the data generated. Data processing activities and techniques used to analyze the data are described and highlights of discoveries made and research undertaken are tabulated.

Gurnett, Donald A.↗

Principles of Space Plasma Wave Instrument Design

Space plasma waves span the frequency range from somewhat below the ion cyclotron frequency to well above the electron cyclotron frequency and plasma frequency. Because of the large frequency range involved, the design of space plasma wave instrumentation presents many interesting challenges. This chapter discusses the principles of space plasma wave instrument design. The topics covered include: performance requirements, electric antennas, magnetic antennas, and signal processing. Where appropriate, comments are made on the likely direction of future developments.

Gurnett, Donald A.↗