Found 183 results
[ Author(Desc)] Title Type Year
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K
Authors: Korendyke Clarence M., Vourlidas Angelos, Plunkett Simon P., Howard Russell A., Wang Dennis, et al.
Title: SPIE ProceedingsDevelopment and test of an active pixel sensor detector for heliospheric imager on solar orbiter and solar probe plus
Abstract: N/A
Date: 10/2013 Publisher: SPIE DOI: 10.1117/12.2027655 Available at: http://proceedings.spiedigitallibrary.org/proceeding.aspx?doi=10.1117/12.2027655
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Authors: Krupar Vratislav, Szabo Adam, Maksimovic Milan, Kruparova Oksana, Kontar Eduard P., et al.
Title: Density Fluctuations in the Solar Wind Based on Type III Radio Bursts Observed by Parker Solar Probe
Abstract:

Radio waves are strongly scattered in the solar wind, so that their apparent sources seem to be considerably larger and shifted than the actual ones. Since the scattering depends on the spectrum of density turbulence, a better understanding of the radio wave propagation provides indirect information on the relative density fluctuations, ϵ=⟨δn⟩/⟨n⟩ ϵ=⟨δn⟩/⟨n⟩ , at the effective turbulence scale length. Here, we analyzed 30 type III bursts detected by Parker Solar Probe (PSP). For the first time, we retrieved type III burst decay times, τ d  τd , between 1 and 10 MHz thanks to an unparalleled temporal resolution of PSP. We observed a significant deviation in a power-law slope for frequencies above 1 MHz. . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 57 DOI: 10.3847/1538-4365/ab65bd Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab65bd
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Authors: Kuznetsov V.D.
Title: Solar and heliospheric space missions
Abstract:

The paper provides a review of the state of the art and prospects of space research in heliophysics, in which a pivotal role belongs to magnetic measurements in the Sun and heliosphere. New space missions, such as the Interhelioprobe, Solar Orbiter, Solar Probe Plus, etc., will follow the currently operating ones (Hinode, SDO, STEREO, etc.) to observe the Sun from short distances and from out-of-ecliptic positions, as well as to conduct in situ measurements in the vicinity of the Sun and outside the ecliptic. The planned coordinated observations within the framework of these missions will allow us to explore the structure and dynamics of magnetic fields in the polar regions of the Sun, to study the mechanisms of the solar dynamo and solar cycle, to gain a deeper insight into the process. . .
Date: 02/2015 Publisher: Advances in Space Research Pages: 879 - 885 DOI: 10.1016/j.asr.2014.07.034 Available at: https://linkinghub.elsevier.com/retrieve/pii/S0273117714004906https://api.elsevier.com/content/article/PII:S0273117714004906?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0273117714004906?httpAccept=text/plain
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Authors: Lamy Philippe, Floyd Olivier, Mikic Zoran, and Riley Pete
Title: Validation of MHD Model Predictions of the Corona with LASCO-C2 Polarized Brightness Images
Abstract:

Progress in our understanding of the solar corona requires that the results of advanced magnetohydrodynamic models driven by measured magnetic fields, and particularly the underlying heating models, be thoroughly compared with coronal observations. The comparison has so far mainly concerned the global morphology of the corona, synthetic images calculated from the models being compared with observed images. We go one step further by performing detailed quantitative comparisons between the calculated polarized radiance p B using the three-dimensional electron density produced by MHD models and well calibrated polarized images obtained by the Large Angle Spectrometric Coronagraph LASCO-C2 coronagraph complemented by ground-based images when available from the Mauna Loa Solar Observatory Ma. . .
Date: 11/2019 Publisher: Solar Physics DOI: 10.1007/s11207-019-1549-9 Available at: http://link.springer.com/10.1007/s11207-019-1549-9http://link.springer.com/content/pdf/10.1007/s11207-019-1549-9.pdfhttp://link.springer.com/content/pdf/10.1007/s11207-019-1549-9.pdfhttp://link.springer.com/article/10.1007/s11207-019-1549-9/fulltext.html
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Authors: Lario D., and Decker R. B.
Title: Estimation of solar energetic proton mission-integrated fluences and peak intensities for missions traveling close to the Sun
Abstract:

A method to estimate both solar energetic particle mission-integrated fluences and solar energetic particle peak intensities for missions traveling through the innermost part of the heliosphere (r < 1 AU) is presented. By using (1) an extensive data set of particle intensities measured at 1 AU over the last three solar cycles, (2) successive launch dates for the mission traveling close to the Sun over the time interval spanned by our data set, and (3) appropriate radial dependences to extrapolate fluences and peak intensities measured at 1 AU to the heliocentric radial distance of the mission at each specific time, we generate distributions of both mission-integrated fluences and maximum peak intensities. From these distributions we extract the values of mission-integrated fluence an. . .
Date: 11/2011 Publisher: Space Weather Pages: n/a - n/a DOI: 10.1029/2011SW000708 Available at: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2011SW000708
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Authors: Lario D.
Title: Estimation of the solar flare neutron worst-case fluxes and fluences for missions traveling close to the Sun
Abstract:

A method to estimate the total fluence of solar flare neutrons at a spacecraft traveling in the innermost part of the heliosphere (at heliocentric radial distances of <1 AU) is presented. The results of the neutron production and emissivity codes of Hua and Lingenfelter (1987a, 1987b) scaled to one of the largest solar neutron events ever observed at the Earth are used to derive a conservative estimate of the energy spectrum of neutrons emitted from the Sun after a large solar flare. By taking into account the survival probability of a neutron to reach a certain heliocentric distance, we evaluate the observed time-integrated spectrum of solar neutrons as a function of the heliocentric distance of the observer. By considering (1) a working relationship between the soft X-ray class of . . .
Date: 03/2012 Publisher: Space Weather Pages: n/a - n/a DOI: 10.1029/2011SW000732 Available at: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2011SW000732
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Authors: Lawrence David J., Feldman William C., Gold Robert E., Goldsten John O., and McNutt Ralph L.
Title: The neutron, gamma-ray, X-ray spectrometer (NGXS): A compact instrument for making combined measurements of neutrons, gamma-rays, and X-rays
Abstract:

The Neutron, Gamma ray, and X-ray Spectrometer (NGXS) is a compact instrument designed to detect neutrons, gamma-rays, and hard X-rays. The original goal of NGXS was to detect and characterize neutrons, gamma-rays, and X-rays from the Sun as part of the Solar Probe Plus mission in order to provide direct insight into particle acceleration, magnetic reconnection, and cross-field transport processes that take place near the Sun. Based on high-energy neutron detections from prompt solar flares, it is estimated that the NGXS would detect neutrons from 15 to 24 impulsive flares. The NGXS sensitivity to 2.2 MeV gamma rays would enable a detection of ̃50-60 impulsive flares. The NGXS is estimated to measure ̃120 counts/s for a GOES C1-type flare at 0.1 AU, which allows for a large dynamic ra. . .
Date: 01/2014 Publisher: Acta Astronautica Pages: 524 - 529 DOI: 10.1016/j.actaastro.2012.06.017 Available at: https://linkinghub.elsevier.com/retrieve/pii/S009457651200255Xhttps://api.elsevier.com/content/article/PII:S009457651200255X?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S009457651200255X?httpAccept=text/plain
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Authors: Le Fur I, De Wit R, Plus M, Oheix J, Derolez V, et al.
Title: Re-oligotrophication trajectories of macrophyte assemblages in Mediterranean coastal lagoons based on 17-year time-series
Abstract:

No abstract


Date: 01/2019 Publisher: Marine Ecology Progress Series Pages: 13 - 32 DOI: 10.3354/meps12814 Available at: https://www.int-res.com/abstracts/meps/v608/p13-32/https://www.int-res.com/articles/meps_oa/m608p013.pdf
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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: Lewis John S.
Title: Observability of spectroscopically active compounds in the atmosphere of Jupiter
Abstract:

The abundances of several hundred volatile compounds have been calculated at several different levels in the atmosphere of Jupiter. Complete chemical equilibrium has been assumed, and a solar-composition, adiabatic-equilibrium model of the atmospheric composition and structure is used throughout. The results which relate to upper limits on the abundances of spectroscopically active compounds in the upper atmosphere are, however, directly applicable to subadiabatic models. The principal results are that only H2, CH4, and NH3 are predicted to be observable with present techniques. These three species are in fact the only compounds conclusively identified in Jupiter spectra to date. A number of plausible previously suggested constituents of the upper atmosp. . .
Date: 05/1969 Publisher: Icarus Pages: 393 - 409 DOI: 10.1016/0019-1035(69)90094-3 Available at: https://linkinghub.elsevier.com/retrieve/pii/0019103569900943https://api.elsevier.com/content/article/PII:0019103569900943?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:0019103569900943?httpAccept=text/plain
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Authors: Li T. C., Drake J. F., and Swisdak M.
Title: DYNAMICS OF DOUBLE LAYERS, ION ACCELERATION, AND HEAT FLUX SUPPRESSION DURING SOLAR FLARES
Abstract:

Observations of flare-heated electrons in the corona typically suggest confinement of electrons. The confinement mechanism, however, remains unclear. The transport of coronal hot electrons into ambient plasma was recently investigated by particle-in-cell (PIC) simulations. Electron transport was significantly suppressed by the formation of a highly localized, nonlinear electrostatic potential in the form of a double layer (DL). In this work large-scale PIC simulations are performed to explore the dynamics of DLs in larger systems where, instead of a single DL, multiple DLs are generated. The primary DL accelerates return current electrons, resulting in high velocity electron beams that interact with ambient ions. This forms a Buneman unstable system that spawns more DLs. Trapping of hea. . .
Date: 09/2014 Publisher: The Astrophysical Journal Pages: 7 DOI: 10.1088/0004-637X/793/1/7 Available at: http://stacks.iop.org/0004-637X/793/i=1/a=7?key=crossref.1ff276d1b5e9632b2d52ebb5720bc5e6
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Authors: Lipatov Alexander S., Jr. Edward C. Sittler, Hartle Richard E., and Cooper John F.
Title: Short wavelength electromagnetic perturbations excited near the Solar Probe Plus spacecraft in the inner heliosphere: 2.5D hybrid modeling
Abstract:

A 2.5D numerical plasma model of the interaction of the solar wind (SW) with the Solar Probe Plus spacecraft (SPPSC) is presented. These results should be interpreted as a basic plasma model derived from the SW interaction with the spacecraft (SC), which could have consequences for both plasma wave and electron plasma measurements on board the SC in the inner heliosphere. Compression waves and electric field jumps with amplitudes of about 1.5 V/m and (12-18) V/m were also observed. A strong polarization electric field was also observed in the wing of the plasma wake. However, 2.5D hybrid modeling did not show excitation of whistler/Alfvén waves in the upstream connected with the bi-directional current closure that was observed in short-time 3D modeling SPPSC and near a tether in the io. . .
Date: 03/2012 Publisher: Planetary and Space Science Pages: 61 - 68 DOI: 10.1016/j.pss.2011.12.008 Available at: https://linkinghub.elsevier.com/retrieve/pii/S0032063311003527https://api.elsevier.com/content/article/PII:S0032063311003527?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0032063311003527?httpAccept=text/plain
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Authors: Longcope Dana
Title: Using Kepler's laws and Rutherford scattering to chart the seven gravity assists in the epic sunward journey of the Parker Solar Probe
Abstract:

On August 12, 2018, NASA launched the Parker Solar Probe (PSP) to explore regions very near the Sun. Losing enough energy and angular momentum to approach the Sun requires either an impractical amount of fuel or a maneuver called a gravity assist. A gravity assist is essentially an elastic collision with a massive, moving target—Rutherford scattering from a planet. Gravity assists are often used to gain energy in missions destined for the outer solar system, but they can also be used to lose energy. Reaching an orbit sufficiently close to the Sun requires that PSP undergoes not one but seven successive gravity assists off the planet Venus. This simple description poses several conceptual challenges to the curious physics student. Why is it so much more challenging to get to the Sun th. . .
Date: 01/2020 Publisher: American Journal of Physics Pages: 11 - 19 DOI: 10.1119/10.0000145 Available at: http://aapt.scitation.org/doi/10.1119/10.0000145http://aapt.scitation.org/doi/pdf/10.1119/10.0000145
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Authors: Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, and Vasylenko A.A.
Title: Future space missions: the inner region of the Solar system
Abstract:

The paper deals with an overview of space missions to explore the inner region of the Solar System, the nearest on time of their launch, namely, Probe Plus, Solar Orbiter, BepiColombo, EXOMars, and InSight. Each of them will study either the Sun or the planet of the Earth group. Their launches are planned for 2018-2020. We describe briefly predestination and technical equipment of spacecrafts, flight plan and scientific goal of these missions.


Date: 10/2017 Publisher: Kosmìčna nauka ì tehnologìâ Pages: 73 - 80 DOI: 10.15407/knit10.15407/knit2017.0310.15407/knit2017.03.073 Available at: http://space-scitechjournal.org.ua/enhttp://space-scitechjournal.org.ua/en/archive/2017/3http://space-scitechjournal.org.ua/en/archive/2017/3/07
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Authors: Maksimovic M., Bale S. D., Berčič L., Bonnell J. W., Case A. W., et al.
Title: Anticorrelation between the Bulk Speed and the Electron Temperature in the Pristine Solar Wind: First Results from the Parker Solar Probe and Comparison with Helios
Abstract:

We discuss the solar wind electron temperatures Te as measured in the nascent solar wind by Parker Solar Probe during its first perihelion pass. The measurements have been obtained by fitting the high-frequency part of quasi-thermal noise spectra recorded by the Radio Frequency Spectrometer. In addition we compare these measurements with those obtained by the electrostatic analyzer discussed in Halekas et al. These first electron observations show an anticorrelation between Te and the wind bulk speed V: this anticorrelation is most likely the remnant of the well-known mapping observed at 1 au and beyond between the fast wind and its coronal hole sources, where electrons are observed to be cooler than in the quiet corona. We also revisit Helios electron temperature . . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 62 DOI: 10.3847/1538-4365/ab61fc Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab61fch
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Authors: Malaspina David M., Halekas Jasper, Berčič Laura, Larson Davin, Whittlesey Phyllis, et al.
Title: Plasma Waves near the Electron Cyclotron Frequency in the Near-Sun Solar Wind
Abstract:

Data from the first two orbits of the Sun by Parker Solar Probe reveal that the solar wind sunward of 50 solar radii is replete with plasma waves and instabilities. One of the most prominent plasma wave power enhancements in this region appears near the electron cyclotron frequency (fce). Most of this wave power is concentrated in electric field fluctuations near 0.7 fce and fce, with strong harmonics of both frequencies extending above fce. At least two distinct, often concurrent, wave modes are observed, preliminarily identified as electrostatic whistler-mode waves and electron Bernstein waves. Wave intervals range in duration from a few seconds to hours. Both the amplitudes and number of detections of these near-fce waves increas. . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 21 DOI: 10.3847/1538-4365/ab4c3b Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab4c3b
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Authors: Malaspina David M., Ergun Robert E., Bolton Mary, Kien Mark, Summers David, et al.
Title: The Digital Fields Board for the FIELDS instrument suite on the Solar Probe Plus mission: Analog and digital signal processing
Abstract:

The first in situ measurements of electric and magnetic fields in the near-Sun environment (< 0.25 AU from the Sun) will be made by the FIELDS instrument suite on the Solar Probe Plus mission. The Digital Fields Board (DFB) is an electronics board within FIELDS that performs analog and digital signal processing, as well as digitization, for signals between DC and 60 kHz from five voltage sensors and four search coil magnetometer channels. These nine input signals are processed on the DFB into 26 analog data streams. A specialized application-specific integrated circuit performs analog to digital conversion on all 26 analog channels simultaneously. The DFB then processes the digital data using a field programmable gate array (FPGA), generating a variety of data products, including dig. . .
Date: 06/2016 Publisher: Journal of Geophysical Research: Space Physics Pages: 5088 - 5096 DOI: 10.1002/2016JA022344 Available at: http://doi.wiley.com/10.1002/2016JA022344http://onlinelibrary.wiley.com/wol1/doi/10.1002/2016JA022344/fullpdf
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Authors: Mann Ingrid, Nouzák Libor, Vaverka Jakub, Antonsen Tarjei, Fredriksen Åshild, et al.
Title: Dust observations with antenna measurements and its prospects for observations with Parker Solar Probe and Solar Orbiter
Abstract:

The electric and magnetic field instrument suite FIELDS on board the NASA Parker Solar Probe and the radio and plasma waves instrument RPW on the ESA Solar Orbiter mission that explore the inner heliosphere are sensitive to signals generated by dust impacts. Dust impacts have been observed using electric field antennas on spacecraft since the 1980s and the method was recently used with a number of space missions to derive dust fluxes. Here, we consider the details of dust impacts, subsequent development of the impact generated plasma and how it produces the measured signals. We describe empirical approaches to characterise the signals and compare these in a qualitative discussion of laboratory simulations to predict signal shapes for spacecraft measurements in the inner solar system. Wh. . .
Date: 12/2019 Publisher: Annales Geophysicae Pages: 1121 - 1140 DOI: 10.5194/angeo-37-1121-2019 Available at: https://www.ann-geophys.net/37/1121/2019/https://www.ann-geophys.net/37/1121/2019/angeo-37-1121-2019.pdf
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Authors: Marchand R., Miyake Y., Usui H., Deca J., Lapenta G., et al.
Title: Cross-comparison of spacecraft-environment interaction model predictions applied to Solar Probe Plus near perihelion
Abstract:

Five spacecraft-plasma models are used to simulate the interaction of a simplified geometry Solar Probe Plus (SPP) satellite with the space environment under representative solar wind conditions near perihelion. By considering similarities and differences between results obtained with different numerical approaches under well defined conditions, the consistency and validity of our models can be assessed. The impact on model predictions of physical effects of importance in the SPP mission is also considered by comparing results obtained with and without these effects. Simulation results are presented and compared with increasing levels of complexity in the physics of interaction between solar environment and the SPP spacecraft. The comparisons focus particularly on spacecraft floating po. . .
Date: 06/2014 Publisher: Physics of Plasmas Pages: 062901 DOI: 10.1063/1.4882439 Available at: http://aip.scitation.org/doi/10.1063/1.4882439http://aip.scitation.org/doi/pdf/10.1063/1.4882439
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Authors: Martinović Mihailo M., Klein Kristopher G., Kasper Justin C., Case Anthony W., Korreck Kelly E., et al.
Title: The Enhancement of Proton Stochastic Heating in the Near-Sun Solar Wind
Abstract:

Stochastic heating (SH) is a nonlinear heating mechanism driven by the violation of magnetic moment invariance due to large-amplitude turbulent fluctuations producing diffusion of ions toward higher kinetic energies in the direction perpendicular to the magnetic field. It is frequently invoked as a mechanism responsible for the heating of ions in the solar wind. Here, we quantify for the first time the proton SH rate Q at radial distances from the Sun as close as 0.16 au, using measurements from the first two Parker Solar Probe encounters. Our results for both the amplitude and radial trend of the heating rate, Q ∝ r−2.5, agree with previous results based on the Helios data set at heliocentric distances from 0.3 to 0.9 au. Also in agreement wit. . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 30 DOI: 10.3847/1538-4365/ab527f Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab527f
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Authors: Matthaeus H., Weygand M., and Dasso S.
Title: Ensemble Space-Time Correlation of Plasma Turbulence in the Solar Wind
Abstract:

Single point measurement turbulence cannot distinguish variations in space and time. We employ an ensemble of one- and two-point measurements in the solar wind to estimate the space-time correlation function in the comoving plasma frame. The method is illustrated using near Earth spacecraft observations, employing ACE, Geotail, IMP-8, and Wind data sets. New results include an evaluation of both correlation time and correlation length from a single method, and a new assessment of the accuracy of the familiar frozen-in flow approximation. This novel view of the space-time structure of turbulence may prove essential in exploratory space missions such as Solar Probe Plus and Solar Orbiter for which the frozen-in flow hypothesis may not be a useful approximation.


Date: 06/2016 Publisher: Physical Review Letters DOI: 10.1103/PhysRevLett.116.245101 Available at: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.245101
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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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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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Authors: McManus Michael D., Bowen Trevor A., Mallet Alfred, Chen Christopher H. K., Chandran Benjamin D. G., et al.
Title: Cross Helicity Reversals in Magnetic Switchbacks
Abstract:

We consider 2D joint distributions of normalized residual energy, σr(s, t), and cross helicity, σc(s, t), during one day of Parker Solar Probe's (PSP's) first encounter as a function of wavelet scale s. The broad features of the distributions are similar to previous observations made by Helios in slow solar wind, namely well-correlated and fairly Alfvénic wind, except for a population with negative cross helicity that is seen at shorter wavelet scales. We show that this population is due to the presence of magnetic switchbacks, or brief periods where the magnetic field polarity reverses. Such switchbacks have been observed before, both in Helios data and in Ulysses data in the polar solar wind. Their abundance and short timescales as seen by PSP in its first enc. . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 67 DOI: 10.3847/1538-4365/ab6dce Available at: https://iopscience.iop.org/article/10.3847/1538-4365
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Authors: Meyer-Vernet N., Issautier K., and Moncuquet M.
Title: Quasi-thermal noise spectroscopy: The art and the practice
Abstract:

Quasi-thermal noise spectroscopy is an efficient tool for measuring in situ macroscopic plasma properties in space, using a passive wave receiver at the ports of an electric antenna. This technique was pioneered on spinning spacecraft carrying very long dipole antennas in the interplanetary medium—like ISEE-3 and Ulysses—whose geometry approached a "theoretician's dream." The technique has been extended to other instruments in various types of plasmas on board different spacecraft and will be implemented on several missions in the near future. Such extensions require different theoretical modelizations, involving magnetized, drifting, or dusty plasmas with various particle velocity distributions and antennas being shorter, biased, or made of unequal wires. We give new analytical app. . .
Date: 08/2017 Publisher: Journal of Geophysical Research: Space Physics Pages: 7925 - 7945 DOI: 10.1002/2017JA024449 Available at: http://doi.wiley.com/10.1002/2017JA024449http://onlinelibrary.wiley.com/wol1/doi/10.1002/2017JA024449/fullpdf
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