Found 11 results
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2020
Authors: Leske R. A., Christian E. R., Cohen C. M. S., Cummings A. C., Davis A. J., et al.
Title: Observations of the 2019 April 4 Solar Energetic Particle Event at the Parker Solar Probe
Abstract:

A solar energetic particle event was detected by the Integrated Science Investigation of the Sun (IS☉IS) instrument suite on Parker Solar Probe (PSP) on 2019 April 4 when the spacecraft was inside of 0.17 au and less than 1 day before its second perihelion, providing an opportunity to study solar particle acceleration and transport unprecedentedly close to the source. The event was very small, with peak 1 MeV proton intensities of ̃0.3 particles (cm2 sr s MeV)-1, and was undetectable above background levels at energies above 10 MeV or in particle detectors at 1 au. It was strongly anisotropic, with intensities flowing outward from the Sun up to 30 times greater than those flowing inward persisting throughout the event. Temporal association between particle incre. . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 35 DOI: 10.3847/1538-4365/ab5712 Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab5712
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Authors: Leske R. A., Christian E. R., Cohen C. M. S., Cummings A. C., Davis A. J., et al.
Title: Observations of the 2019 April 4 Solar Energetic Particle Event at the Parker Solar Probe
Abstract:

A solar energetic particle event was detected by the Integrated Science Investigation of the Sun (IS☉IS) instrument suite on Parker Solar Probe (PSP) on 2019 April 4 when the spacecraft was inside of 0.17 au and less than 1 day before its second perihelion, providing an opportunity to study solar particle acceleration and transport unprecedentedly close to the source. The event was very small, with peak 1 MeV proton intensities of ̃0.3 particles (cm2 sr s MeV)−1, and was undetectable above background levels at energies above 10 MeV or in particle detectors at 1 au. It was strongly anisotropic, with intensities flowing outward from the Sun up to 30 times greater than those flowing inward persisting throughout the event. Temporal association between particle inc. . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 35 DOI: 10.3847/1538-4365/ab5712 Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab5712
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Authors: Desai M. I., Mitchell D. G., Szalay J. R., Roelof E. C., Giacalone J., et al.
Title: Properties of Suprathermal-through-energetic He Ions Associated with Stream Interaction Regions Observed over the Parker Solar Probe ’s First Two Orbits
Abstract:

The Integrated Science Investigation of the Sun (IS☉IS) suite on board NASA's Parker Solar Probe (PSP) observed six distinct enhancements in the intensities of suprathermal-through-energetic (∼0.03─3 MeV nucleon−1) He ions associated with corotating or stream interaction regions (CIR or SIR) during its first two orbits. Our results from a survey of the time histories of the He intensities, spectral slopes, and anisotropies and the event-averaged energy spectra during these events show the following: (1) In the two strongest enhancements, seen at 0.35 and 0.85 au, the higher-energy ions arrive and maximize later than those at lower energies. In the event seen at 0.35 au, the He ions arrive when PSP was away from the SIR trailing edge and entered the rarefaction region . . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 56 DOI: 10.3847/1538-4365/ab65ef Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab65efhttps://iopscience.iop.org/article/10.3847/1538-4365/ab65ef/
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Authors: Hill M. E., Mitchell D. G., Allen R. C., de Nolfo G. A., Vourlidas A., et al.
Title: Small, Low-energy, Dispersive Solar Energetic Particle Events Observed by Parker Solar Probe
Abstract:

The Energetic Particle Instrument─Low Energy (EPI-Lo) experiment has detected several weak, low-energy (̃30─300 keV nucleon─1) solar energetic particle (SEP) events during its first two closest approaches to the Sun, providing a unique opportunity to explore the sources of low-energy particle acceleration. As part of the Parker Solar Probe (PSP) Integrated Science Investigation of the Sun (IS☉IS) suite, EPI-Lo was designed to investigate the physics of energetic particles; however, in the special lowest-energy "time-of-flight only" product used in this study, it also responds to solar photons in a subset of approximately sunward-looking apertures lacking special light-attenuating foils. During the first three perihelia, in a frame rotating with the Sun, PSP undergoes. . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 65 DOI: 10.3847/1538-4365/ab643d Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab643
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Authors: Hill M. E., Mitchell D. G., Allen R. C., de Nolfo G. A., Vourlidas A., et al.
Title: Small, Low-energy, Dispersive Solar Energetic Particle Events Observed by Parker Solar Probe
Abstract:

The Energetic Particle Instrument-Low Energy (EPI-Lo) experiment has detected several weak, low-energy (̃30-300 keV nucleon-1) solar energetic particle (SEP) events during its first two closest approaches to the Sun, providing a unique opportunity to explore the sources of low-energy particle acceleration. As part of the Parker Solar Probe (PSP) Integrated Science Investigation of the Sun (IS☉IS) suite, EPI-Lo was designed to investigate the physics of energetic particles; however, in the special lowest-energy "time-of-flight only" product used in this study, it also responds to solar photons in a subset of approximately sunward-looking apertures lacking special light-attenuating foils. During the first three perihelia, in a frame rotating with the Sun, PSP undergoes retro. . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 65 DOI: 10.3847/1538-4365/ab643d Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab643
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2019
Authors: McComas D. J., Christian E. R., Cohen C. M. S., Cummings A. C., Davis A. J., et al.
Title: Probing the energetic particle environment near the Sun
Abstract:

NASA’s Parker Solar Probe mission recently plunged through the inner heliosphere of the Sun to its perihelia, about 24 million kilometres from the Sun. Previous studies farther from the Sun (performed mostly at a distance of 1 astronomical unit) indicate that solar energetic particles are accelerated from a few kiloelectronvolts up to near-relativistic energies via at least two processes: "impulsive" events, which are usually associated with magnetic reconnection in solar flares and are typically enriched in electrons, helium-3 and heavier ions, and "gradual" events, which are typically associated with large coronal-mass-ejection-driven shocks and compressions moving through the corona and inner solar wind and are the dominant source of protons with energies between 1 and 10 megaelect. . .
Date: 12/2019 Publisher: Nature Pages: 223 - 227 DOI: 10.1038/s41586-019-1811-1 Available at: http://www.nature.com/articles/s41586-019-1811-1
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Authors: McComas D. J., Christian E. R., Cohen C. M. S., Cummings A. C., Davis A. J., et al.
Title: Probing the energetic particle environment near the Sun
Abstract:

NASA's Parker Solar Probe mission recently plunged through the inner heliosphere of the Sun to its perihelia, about 24 million kilometres from the Sun. Previous studies farther from the Sun (performed mostly at a distance of 1 astronomical unit) indicate that solar energetic particles are accelerated from a few kiloelectronvolts up to near-relativistic energies via at least two processes: "impulsive" events, which are usually associated with magnetic reconnection in solar flares and are typically enriched in electrons, helium-3 and heavier ions, and "gradual" events, which are typically associated with large coronal-mass-ejection-driven shocks and compressions moving through the corona and inner solar wind and are the dominant source of protons with energies between 1 and 10 megaelectro. . .
Date: 12/2019 Publisher: Nature Pages: 223 - 227 DOI: 10.1038/s41586-019-1811-1 Available at: http://www.nature.com/articles/s41586-019-1811-1
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2017
Authors: Hill M. E., Mitchell D. G., Andrews G. B., Cooper S. A., Gurnee R. S., et al.
Title: The Mushroom: A half-sky energetic ion and electron detector
Abstract:

We present a time-of-flight mass spectrometer design for the measurement of ions in the 30 keV to 10 MeV range for protons (up to 40 MeV and 150 MeV for He and heavy ions, respectively) and 30 keV to 1 MeV range for electrons, covering half of the sky with 80 apertures. The instrument, known as the "Mushroom," owing to its shape, solves the field of view problem for magnetospheric and heliospheric missions that employ three-axis stabilized spacecraft, yet still require extended angular coverage; the Mushroom is also compatible with a spinning spacecraft. The most important new feature of the Mushroom is the method through which uncomplicated electrostatic optics and clean position sensing combine to permit many apertures to fit into a compact, low-mass sensor head (or wedge), several of. . .
Date: 02/2017 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2016JA022614 Available at: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/2016JA022614
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Authors: Hill M. E., Mitchell D. G., Andrews G. B., Cooper S. A., Gurnee R. S., et al.
Title: The Mushroom: A half-sky energetic ion and electron detector
Abstract:

We present a time-of-flight mass spectrometer design for the measurement of ions in the 30 keV to 10 MeV range for protons (up to 40 MeV and 150 MeV for He and heavy ions, respectively) and 30 keV to 1 MeV range for electrons, covering half of the sky with 80 apertures. The instrument, known as the "Mushroom," owing to its shape, solves the field of view problem for magnetospheric and heliospheric missions that employ three-axis stabilized spacecraft, yet still require extended angular coverage; the Mushroom is also compatible with a spinning spacecraft. The most important new feature of the Mushroom is the method through which uncomplicated electrostatic optics and clean position sensing combine to permit many apertures to fit into a compact, low-mass sensor head (or wedge), several of. . .
Date: 02/2017 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2016JA022614 Available at: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/2016JA022614
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2014
Authors: McComas D. J., Alexander N., Angold N., Bale S., Beebe C., et al.
Title: Integrated Science Investigation of the Sun (ISIS): Design of the Energetic Particle Investigation
Abstract:

The Integrated Science Investigation of the Sun (ISIS) is a complete science investigation on the Solar Probe Plus (SPP) mission, which flies to within nine solar radii of the Sun’s surface. ISIS comprises a two-instrument suite to measure energetic particles over a very broad energy range, as well as coordinated management, science operations, data processing, and scientific analysis. Together, ISIS observations allow us to explore the mechanisms of energetic particles dynamics, including their: (1) Origins—defining the seed populations and physical conditions necessary for energetic particle acceleration; (2) Acceleration—determining the roles of shocks, reconnection, waves, and turbulence in accelerating energetic particles; and (3) Transport—revealing how ener. . .
Date: 07/2014 Publisher: Space Science Reviews DOI: 10.1007/s11214-014-0059-1 Available at: http://link.springer.com/content/pdf/10.1007/s11214-014-0059-1
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Authors: McComas D. J., Alexander N., Angold N., Bale S., Beebe C., et al.
Title: Integrated Science Investigation of the Sun (ISIS): Design of the Energetic Particle Investigation
Abstract:

The Integrated Science Investigation of the Sun (ISIS) is a complete science investigation on the Solar Probe Plus (SPP) mission, which flies to within nine solar radii of the Sun’s surface. ISIS comprises a two-instrument suite to measure energetic particles over a very broad energy range, as well as coordinated management, science operations, data processing, and scientific analysis. Together, ISIS observations allow us to explore the mechanisms of energetic particles dynamics, including their: (1) Origins—defining the seed populations and physical conditions necessary for energetic particle acceleration; (2) Acceleration—determining the roles of shocks, reconnection, waves, and turbulence in accelerating energetic particles; and (3) Transport—revealing how ener. . .
Date: 07/2014 Publisher: Space Science Reviews DOI: 10.1007/s11214-014-0059-1 Available at: http://link.springer.com/content/pdf/10.1007/s11214-014-0059-1
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