A5009019933- Solar and Space Plasma Dynamics
- Astro and Planetary Science
- Ionosphere and magnetosphere dynamics
- Planetary Science and Exploration
- Radiation Therapy and Dosimetry
- Gamma-ray bursts and supernovae
- Scientific Research and Discoveries
- Dark Matter and Cosmic Phenomena
- Earthquake Detection and Analysis
- Geomagnetism and Paleomagnetism Studies
- Space Science and Extraterrestrial Life
- Astrophysics and Cosmic Phenomena
- Nuclear Physics and Applications
- Solar Radiation and Photovoltaics
- Radiation Detection and Scintillator Technologies
- Spaceflight effects on biology
- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Atmospheric Ozone and Climate
- Particle Detector Development and Performance
- Geophysics and Gravity Measurements
- Methane Hydrates and Related Phenomena
- International Maritime Law Issues
- International Environmental Law and Policies
- Spacecraft Design and Technology
The Aerospace Corporation
2016-2025
NOAA Physical Sciences Laboratory
2023
University of Colorado System
2023
Goddard Space Flight Center
2023
Bowie State University
2023
Aerospace Institute (Germany)
2023
California Institute of Technology
2023
Southwest Research Institute
2016
University of New Hampshire
2016
University of Tennessee at Knoxville
2016
This paper describes the Magnetic Electron Ion Spectrometer (MagEIS) instruments aboard RBSP spacecraft from an instrumentation and engineering point of view. There are four magnetic spectrometers each two spacecraft, one low-energy unit (20–240 keV), medium-energy units (80–1200 a high-energy (800–4800 keV). The high also contains proton telescope (55 keV–20 MeV). focus electrons within selected energy pass band upon focal plane several silicon detectors where pulse-height analysis is used...
The disappearance and reappearance of outer zone energetic electrons during the November 3–4, 1993, magnetic storm is examined utilizing data from Solar, Anomalous, Magnetospheric Particle Explorer (SAMPEX), Global Positioning System (GPS) series, Los Alamos National Laboratory (LANL) sensors onboard geosynchronous satellites. relativistic electron flux drops main phase in association with large negative interplanetary B z rapid solar wind pressure increase late on 3. Outer E > 3 MeV...
We examine signatures of two types waves that may be involved in the acceleration energetic electrons Earth's outer radiation belts. have compiled a database ULF wave power from SAMNET and IMAGE ground magnetometer stations for 1987–2001. Long‐duration, comprehensive, situ VLF/ELF chorus observations are not available, so we infer activity low‐altitude SAMPEX MeV electron microbursts 1996–2001 since thought to caused by interactions between trapped electrons. compare microburst observed...
The extraordinary period from late October through early November 2003 was marked by more than 40 coronal mass ejections (CME), eight X‐class flares, and five large solar energetic particle (SEP) events. Using data instruments on the ACE, SAMPEX, GOES‐11 spacecraft, fluences of H, He, O, electrons have been measured in these events over energy interval ∼0.1 to >100 MeV/nucleon for ions ∼0.04 8 MeV electrons. O spectra are found resemble double power laws, with a break spectral index...
The Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX), a low‐altitude polar‐orbiting satellite, has provided long‐term global picture of the radiation belts since its launch on July 3, 1992. While inner belt ( L < 2) protons appear to have only solar cycle variation, outer > electrons vary cycle, semiannual, rotation time scales, with geomagnetic storms. Recently developed models predicting MeV electron at geostationary orbit [Li et al., 2001] Dst index [Temerin Li, based...
Bursty precipitation of relativistic electrons has been implicated as a major loss process during magnetic storms. One type precipitation, microbursts, appears to contain enough empty the prestorm outer radiation belt in approximately day. During storms that result high fluxes trapped electrons, microbursts continue for several days into recovery phase, when are dramatically increasing. The present study shows this apparent inconsistency is resolved by observations number lost through 10–100...
Abstract We describe an automated computer algorithm designed to remove background contamination from the Van Allen Probes Magnetic Electron Ion Spectrometer (MagEIS) electron flux measurements. provide a detailed description of with illustrative examples on‐orbit data. find two primary sources in MagEIS data: inner zone protons and bremsstrahlung X‐rays generated by energetic electrons interacting spacecraft material. Bremsstrahlung primarily produce lower energy channels (∼30–500 keV)...
A theoretical calculation provides inner radiation belt proton intensities as a function of time and the three adiabatic invariants, M , K L in kinetic energy range from ∼10 MeV to ∼4 GeV 1.1 2.4. Long residence times for trapped protons up several thousand years require similarly long input series geomagnetic field, solar activity, fluences. Additional inputs include galactic cosmic ray spectra, nuclear scattering cross sections, neutral plasma densities atmosphere, ionosphere,...
Prior to 2003, there are two known cases where ultrarelativistic (≳10 MeV) electrons appeared in the Earth's inner zone radiation belts association with high speed interplanetary shocks: 24 March 1991 and less well studied 21 February 1994 storms. During event were injected into on a timescale of minutes, producing new stably trapped belt population that persisted for ∼10 years. More recently, at end solar cycle 23, number violent geomagnetic disturbances resulted large variations zone,...
Based on SAMPEX/PET observations, the rates and spatial temporal variations of electron loss to atmosphere in Earth's radiation belt were quantified using a drift diffusion model that includes effects azimuthal pitch angle diffusion. The measured electrons by SAMPEX can be distinguished as trapped, quasi‐trapped (in cone), precipitating bounce cone). simulates low‐altitude distribution from SAMPEX. After fitting results data, magnitudes lifetime quantitatively determined based optimum...
Abstract Measurements from the Relativistic Electron and Proton Telescope integrated little experiment (REPTile) on board Colorado Student Space Weather Experiment (CSSWE) CubeSat mission, which was launched into a highly inclined (65°) low Earth orbit, are analyzed along with measurements (REPT) Magnetic Ion Spectrometer (MagEIS) instruments aboard Van Allen Probes, in inclination (10°) geo‐transfer‐like orbit. Both REPT MagEIS measure full distribution of energetic electrons as they...
Using data from WIND, SAMPEX (Solar Anomalous, and Magnetospheric Particle Explorer), the Los Alamos National Laboratory (LANL) sensors onboard geostationary satellites, we investigate correlation of energetic electrons in 20–200 keV range solar wind high speed streams with relativistic magnetosphere to determine whether are source outer electron radiation belt. Though there is some between enhancements belt, phase space density not adequate supply belt electrons. Although lower energy could...
Observations of relativistic (>1 MeV) electron microbursts by the Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX) satellite are frequently associated with geomagnetic storms. We examine characteristics these during 1997 1998, paying particular attention to three storms selected Geospace Environment Modeling (GEM) community for special study: May 15, 1997, September 25, October 19, 1998. The strongly correlate both Dst Kp indices generally increase in intensity move lower L...
We report on the ionization states of ∼0.5–50 MeV/nucleon ions in 6 November 1997 solar particle event using instrumentation SAMPEX satellite and geomagnetic cutoff technique. Using cutoffs ∼10 MeV 4 He ∼20 protons, we infer C‐Fe by measuring their latitude distributions. The method extends measurement beyond 10 MeV/nucleon, where charge state information is inaccessible with present electrostatic deflection techniques. In contrast to an increase Fe observed above events late 1992, find that...
[1] We present multi-satellite observations of large amplitude radiation belt whistler-mode waves and relativistic electron precipitation. On separate occasions during the Wind petal orbits STEREO phasing orbits, recorded intense in outer nightside equatorial with peak-to-peak amplitudes exceeding 300 mV/m. During these intervals wave activity, SAMPEX microbursts near magnetic conjunction STEREO. This evidence microburst precipitation occurring at same time nearly local L-shell a bursty...
Semiconducting TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> displays non-volatile multi-state, hysteretic behavior in its I-V characteristics that can be exploited as a memory material memristive device. We exposed devices the <i xmlns:xlink="http://www.w3.org/1999/xlink">on</i> and xmlns:xlink="http://www.w3.org/1999/xlink">off</i> resistance states to 45 Mrad(Si) of ~1-MeV gamma radiation 23 941-MeV Bi-ions under zero bias...
Abstract We present measurements of relativistic electrons (0.7–1.5 MeV) in the inner zone and slot region obtained by Magnetic Electron Ion Spectrometer (MagEIS) instrument on Van Allen Probes. The data presented are corrected for background contamination, which is primarily due to inner‐belt protons these low‐ L regions. find that ∼1 MeV were transported into following two largest geomagnetic storms Probes era date, March June 2015 events. As not observed prior events, injections created a...
We describe a new, more accurate procedure for estimating and removing inner zone background contamination from Van Allen Probes Magnetic Electron Ion Spectrometer (MagEIS) radiation belt measurements. This new is based on the underlying assumption that primary source of in electron measurements at L shells less than three, energetic protons, relatively stable. Since magnetic spectrometer can readily distinguish between foreground electrons signals, we are able to exploit proton stability...
Abstract Over the last decade, solar wind has exhibited low densities and magnetic field strengths, representing anomalous states that have never been observed during space age. As discussed by Schwadron, Blake, et al. (2014, https://doi.org/10.1002/2014SW001084 ), cycle 23–24 activity led to longest minimum in more than 80 years continued into “mini” maximum of 24. During this weak activity, we galactic cosmic ray fluxes exceeded theERobserved small energetic particle events. Here provide...
The occurrence frequency of precipitation bursts > 1 MeV electrons in the outer radiation belt is examined using data from SAMPEX satellite. Electron burst characteristics shown this paper include dependence on magnetic local time, radial distance and geomagnetic activity. Precipitation with timescales <1 s, i.e., microbursts, are studied detail, including their phases storms. It found that occur typically region between L = 4 6. Microbursts tend to at lower than several tens seconds....