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2020
Authors: Chen Yu, and Hu Qiang
Title: Effects of Radial Distances on Small-scale Magnetic Flux Ropes in the Solar Wind
Abstract:

Small-scale magnetic flux ropes (SFRs) in the solar wind have been studied for decades. Statistical analysis utilizing various in situ spacecraft measurements is the main observational approach to investigating the generation and evolution of these small-scale structures. Based on the Grad-Shafranov reconstruction technique, we use the automated detection algorithm to build the databases of these small-scale structures via various spacecraft measurements at different heliocentric distances. We present the SFR properties, including the magnetic field and plasma parameters at different radial distances from the Sun near the ecliptic plane. It is found that the event occurrence rate is still of the order of a few hundreds per month, the duration and scale-size distributions follow power la. . .
Date: 05/2020 Publisher: The Astrophysical Journal Pages: 25 DOI: 10.3847/1538-4357/ab8294 Available at: https://iopscience.iop.org/article/10.3847/1538-4357/ab8294
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Authors: Halekas J. S., Whittlesey P., Larson D. E., McGinnis D., Maksimovic M., et al.
Title: Electrons in the Young Solar Wind: First Results from the Parker Solar Probe
Abstract:

The Solar Wind Electrons Alphas and Protons experiment on the Parker Solar Probe (PSP) mission measures the three-dimensional electron velocity distribution function. We derive the parameters of the core, halo, and strahl populations utilizing a combination of fitting to model distributions and numerical integration for ̃100,000 electron distributions measured near the Sun on the first two PSP orbits, which reached heliocentric distances as small as ̃0.17 au. As expected, the electron core density and temperature increase with decreasing heliocentric distance, while the ratio of electron thermal pressure to magnetic pressure (βe) decreases. These quantities have radial scaling consistent with previous observations farther from the Sun, with superposed variations associated. . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 22 DOI: 10.3847/1538-4365/ab4cec Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab4cec
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Authors: Cohen C. M. S., Christian E. R., Cummings A. C., Davis A. J., Desai M. I., et al.
Title: Energetic Particle Increases Associated with Stream Interaction Regions
Abstract:

The Parker Solar Probe was launched on 2018 August 12 and completed its second orbit on 2019 June 19 with perihelion of 35.7 solar radii. During this time, the Energetic Particle Instrument-Hi (EPI-Hi, one of the two energetic particle instruments comprising the Integrated Science Investigation of the Sun, IS☉IS) measured seven proton intensity increases associated with stream interaction regions (SIRs), two of which appear to be occurring in the same region corotating with the Sun. The events are relatively weak, with observed proton spectra extending to only a few MeV and lasting for a few days. The proton spectra are best characterized by power laws with indices ranging from −4.3 to −6.5, generally softer than events associated with SIRs observed at 1 au and beyond. Helium spec. . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 20 DOI: 10.3847/1538-4365/ab4c38 Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab4c38
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Authors: Joyce C. J., McComas D. J., Christian E. R., Schwadron N. A., Wiedenbeck M. E., et al.
Title: Energetic Particle Observations from the Parker Solar Probe Using Combined Energy Spectra from the IS⊙IS Instrument Suite
Abstract:

The Integrated Science Investigations of the Sun (IS☉IS) instrument suite includes two Energetic Particle instruments: EPI-Hi, designed to measure ions from ̃1 to 200 MeV nuc−1, and EPI-Lo, designed to measure ions from ̃20 to ̃15 MeV nuc−1. We present an analysis of eight energetic proton events observed across the energy range of both instruments during Parker Solar Probe's (PSP) first two orbits in order to examine their combined energy spectra. Background corrections are applied to help resolve spectral breaks between the two instruments and are shown to be effective. In doing so we demonstrate that even in the early stages of calibration, IS☉IS is capable of producing reliable spectral observations across broad energy ranges. In addition to making g. . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 41 DOI: 10.3847/1538-4365/ab5948 Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab5948
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Authors: Bandyopadhyay Riddhi, Goldstein M. L., Maruca B. A., Matthaeus W. H., Parashar T. N., et al.
Title: Enhanced Energy Transfer Rate in Solar Wind Turbulence Observed near the Sun from Parker Solar Probe
Abstract:

Direct evidence of an inertial-range turbulent energy cascade has been provided by spacecraft observations in heliospheric plasmas. In the solar wind, the average value of the derived heating rate near 1 au is ∼10 3 Jkg −1 s −1  ∼103Jkg−1s−1 , an amount sufficient to account for observed departures from adiabatic expansion. Parker Solar Probe, even during its first solar encounter, offers the first opportunity to compute, in a similar fashion, a fluid-scale energy decay rate, much closer to the solar corona than any prior in situ observations. Using the Politano─Pouquet third-order law and the von Kármán decay law, we estimate the fluid-range energy transfer rate in the inner heliosphere, at heliocentric distance R ranging from 54 RDate: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 48 DOI: 10.3847/1538-4365/ab5dae Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab5dae
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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: Chen C. H. K., Bale S. D., Bonnell J. W., Borovikov D., Bowen T. A., et al.
Title: The Evolution and Role of Solar Wind Turbulence in the Inner Heliosphere
Abstract:

The first two orbits of the Parker Solar Probe spacecraft have enabled the first in situ measurements of the solar wind down to a heliocentric distance of 0.17 au (or 36 R ⊙  R⊙ ). Here, we present an analysis of this data to study solar wind turbulence at 0.17 au and its evolution out to 1 au. While many features remain similar, key differences at 0.17 au include increased turbulence energy levels by more than an order of magnitude, a magnetic field spectral index of −3/2 matching that of the velocity and both Elsasser fields, a lower magnetic compressibility consistent with a smaller slow-mode kinetic energy fraction, and a much smaller outer scale that has had time for substantial nonlinear processing. There is also an overall increase in the dominance o. . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 53 DOI: 10.3847/1538-4365/ab60a3 Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab60a3
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Authors: Macneil Allan R, Owens Mathew J, Wicks Robert T, Lockwood Mike, Bentley Sarah N, et al.
Title: The evolution of inverted magnetic fields through the inner heliosphereABSTRACT
Abstract:

Local inversions are often observed in the heliospheric magnetic field (HMF), but their origins and evolution are not yet fully understood. Parker Solar Probe has recently observed rapid, Alfvénic, HMF inversions in the inner heliosphere, known as 'switchbacks', which have been interpreted as the possible remnants of coronal jets. It has also been suggested that inverted HMF may be produced by near-Sun interchange reconnection; a key process in mechanisms proposed for slow solar wind release. These cases suggest that the source of inverted HMF is near the Sun, and it follows that these inversions would gradually decay and straighten as they propagate out through the heliosphere. Alternatively, HMF inversions could form during solar wind transit, through phenomena such velocity shears, . . .
Date: 04-2020 Publisher: Monthly Notices of the Royal Astronomical Society Pages: 3642 - 3655 DOI: 10.1093/mnras/staa951 Available at: https://academic.oup.com/mnras/article/494/3/3642/5819029
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Authors: Page Brent, Bale Stuart D., Bonnell J. W., Goetz Keith, Goodrich Katherine, et al.
Title: Examining Dust Directionality with the Parker Solar Probe FIELDS Instrument
Abstract:

Parker Solar Probe's (PSP's) FIELDS instrument provides a measure of the dust impact rate on the spacecraft with a full-coverage summary of the voltages recorded by the spacecraft's antennas. From consecutively sampled periods throughout PSP's orbit, FIELDS stores the maximum amplitude measured by each active antenna. The occurrence of a dust impact during a given period can be identified by these amplitudes exceeding a few tens of millivolts, and a dust grain's impact location can be approximated using the differential amplitudes between antennas. The impact locations indicated in the data are inspected for compatibility with the incident directions of prograde, retrograde, and β-meteoroid orbits in the ecliptic. Important features in the data are consistent with the incidence of β-m. . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 51 DOI: 10.3847/1538-4365/ab5f6a Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab5f6a
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Authors: Panasenco Olga, Velli Marco, D’Amicis Raffaella, Shi Chen, Réville Victor, et al.
Title: Exploring Solar Wind Origins and Connecting Plasma Flows from the Parker Solar Probe to 1 au: Nonspherical Source Surface and Alfvénic Fluctuations
Abstract:

The magnetic field measurements of the FIELDS instrument on the Parker Solar Probe (PSP) have shown intensities, throughout its first solar encounter, that require a very low source surface (SS) height ( R SS ⩽1.8R ⊙  RSS⩽1.8R⊙ ) to be reconciled with magnetic field measurements at the Sun via potential field extrapolation (PFSS). However, during PSP's second encounter, the situation went back to a more classic SS height ( R SS ⩽2.5R ⊙  RSS⩽2.5R⊙ ). Here we use high-resolution observations of the photospheric magnetic field (Solar Dynamics Observatory/Helioseismic and Magnetic Imager) to calculate neutral lines and boundaries of the open field regions for SS heights from 1.2 to 2.5 RDate: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 54 DOI: 10.3847/1538-4365/ab61f4 Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab61f4
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Authors: Parker Eugene N.
Title: Exploring the innermost solar atmosphere
Abstract:

The Parker Solar Probe spacecraft completed the first two of its 24 scheduled orbits around the Sun on 18 June 2019, making history by flying halfway between Mercury and the Sun.


Date: 01/2020 Publisher: Nature Astronomy Pages: 19 - 20 DOI: 10.1038/s41550-019-0985-7 Available at: http://www.nature.com/articles/s41550-019-0985-7
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2019
Authors: Wilson Lynn B., Chen Li-Jen, Wang Shan, Schwartz Steven J., Turner Drew L., et al.
Title: Electron Energy Partition across Interplanetary Shocks. II. Statistics
Abstract:

A statistical analysis of 15,210 electron velocity distribution function (VDF) fits, observed within ±2 hr of 52 interplanetary (IP) shocks by the Wind spacecraft near 1 au, is presented. This is the second in a three-part series on electron VDFs near IP shocks. The electron velocity moment statistics for the dense, low-energy core, tenuous, hot halo, and field-aligned beam/strahl are a statistically significant list of values illustrated with both histograms and tabular lists for reference and baselines in future work. Given the large statistics in this investigation, the beam/strahl fit results in the upstream are now the most comprehensive attempt to parameterize the beam/strahl electron velocity moments in the ambient solar wind. The median density, temperature, beta, and temperatu. . .
Date: 12/2019 Publisher: The Astrophysical Journal Supplement Series Pages: 24 DOI: 10.3847/1538-4365/ab5445 Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab5445
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Authors: Al-Haddad Nada, Lugaz Noé, Poedts Stefaan, Farrugia Charles J., Nieves-Chinchilla Teresa, et al.
Title: Evolution of Coronal Mass Ejection Properties in the Inner Heliosphere: Prediction for the Solar Orbiter and Parker Solar Probe
Abstract:

The evolution of the magnetic field and plasma quantities inside a coronal mass ejection (CME) with distance are known from statistical studies using data from 1 au monitors, planetary missions, Helios, and Ulysses. This does not cover the innermost heliosphere, below 0.29 au, where no data are yet publicly available. Here, we describe the evolution of the properties of simulated CMEs in the inner heliosphere using two different initiation mechanisms. We compare the radial evolution of these properties with that found from statistical studies based on observations in the inner heliosphere by Helios and MESSENGER. We find that the evolution of the radial size and magnetic field strength is nearly indistinguishable for twisted flux rope from that of writhed CMEs. The evolution of these pr. . .
Date: 10/2019 Publisher: The Astrophysical Journal Pages: 179 DOI: 10.3847/1538-4357/ab4126 Available at: https://iopscience.iop.org/article/10.3847/1538-4357/ab4126
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2018
Authors: Yoon Peter H., Hwang Junga, ópez Rodrigo A., Kim Sunjung, and Lee Jaejin
Title: Electromagnetic Thermal Noise in Upper-Hybrid Frequency Range
Abstract:

The inner magnetosphere including the radiation belt and ring current environment is replete with high-frequency fluctuations with peak intensity occurring near upper-hybrid frequency and/or multiple harmonic electron cyclotron frequencies above and below the upper-hybrid frequency. Past and contemporary spacecraft missions, including the Van Allen Probes, were designed to detect the electric field spectrum only for these high-frequency fluctuations. Making use of the recently formulated generalized theory of electromagnetic spontaneous emission in thermal magnetized plasmas, it is shown that upper-hybrid/multiple harmonic electron cyclotron emissions are characterized by a significant magnetic field component, even in the high-frequency regime. Such a prediction may potentially be test. . .
Date: 07/2018 Publisher: Journal of Geophysical Research: Space Physics Pages: 5356 - 5363 DOI: 10.1029/2018JA025459 Available at: http://onlinelibrary.wiley.com/wol1/doi/10.1029/2018JA025459/fullpdf
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Authors: Stenborg Guillermo, Stauffer Johnathan R., and Howard Russell A.
Title: Evidence for a Circumsolar Dust Ring Near Mercury’s Orbit
Abstract:

To test a technique to be used on the white-light imager onboard the recently launched Parker Solar Probe mission, we performed a numerical differentiation of the brightness profiles along the photometric axis of the F-corona models that are derived from STEREO Ahead Sun Earth Connection Heliospheric Investigation observations recorded with the HI-1 instrument between 2007 December and 2014 March. We found a consistent pattern in the derivatives that can be observed from any S/C longitude between about 18° and 23° elongation with a maximum at about 21°. These findings indicate the presence of a circumsolar dust density enhancement that peaks at about 23° elongation. A straightforward integration of the excess signal in the derivative space indicates that the brightness increase over. . .
Date: 11/2018 Publisher: The Astrophysical Journal Pages: 74 DOI: 10.3847/1538-4357/aae6cb Available at: http://stacks.iop.org/0004-637X/868/i=1/a=74?key=crossref.819ea43bc5d8ac7ce2e4d9090800ae03
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2016
Authors: Fox Nicola J., and McComas David J.
Title: Editorial: Topical Volume on Developing the Solar Probe Plus Mission
Abstract:

The Solar Probe Plus mission is a remarkable and historic step in the exploration of humankind. We have visited all of the planets and a number of other smaller moons and bodies; we have explored the magnetospheres, not just of Earth but also of all the planets; and we have explored our heliosphere and even flown a spacecraft beyond its boundary and into interstellar space itself. However, only with the launch of Solar Probe Plus will we actually visit our own star—the Sun—repeatedly traveling to within 9 solar radii (R S  RS ) of its surface (10R S  10RS heliocentric) and directly through its corona. From here, we will at long last be able to solve the key mysteries that have puzzled scientists for over 50 years: how the corona is heated and how the so. . .
Date: 12/2016 Publisher: Space Science Reviews Pages: 1 - 6 DOI: 10.1007/s11214-016-0323-7 Available at: http://link.springer.com/10.1007/s11214-016-0323-7http://link.springer.com/content/pdf/10.1007/s11214-016-0323-7.pdfhttp://link.springer.com/content/pdf/10.1007/s11214-016-0323-7.pdfhttp://link.springer.com/article/10.1007/s11214-016-0323-7/fulltext.html
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Authors: Brodu E., and Balat-Pichelin M.
Title: Emissivity of Boron Nitride and Metals for the Solar Probe Plus Mission
Abstract:
For application to the Solar Probe Plus mission (NASA), the behavior and the thermo-optical performance at very high temperatures (range 1100–2200 K) of candidate passive thermal control materials was assessed. On one hand, a pyrolytic boron nitride coating (130  μm 130  μm thick) was proved to be stable at high temperatures up to 2200 K in vacuum, as well as proved, via total and spectral emissivity measurements at high temperatures, to be able to effectively turn an initially selective solar absorber substrate (carbon/carbon composite) into a solar reflector. On the other hand, chemical vapor deposition coatings made of refractory metals with highly textured surfaces were proved to be able to significantly reduce the temperature of a metall. . .
Date: 11/2016 Publisher: Journal of Spacecraft and Rockets Pages: 1119 - 1127 DOI: 10.2514/1.A33453 Available at: https://arc.aiaa.org/doi/10.2514/1.A33453https://arc.aiaa.org/doi/pdf/10.2514/1.A33453
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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: Klein Kristopher G., and Chandran Benjamin D. G.
Title: EVOLUTION OF THE PROTON VELOCITY DISTRIBUTION DUE TO STOCHASTIC HEATING IN THE NEAR-SUN SOLAR WIND
Abstract:

We investigate how the proton distribution function evolves when the protons undergo stochastic heating by strong, low-frequency, Alfvén-wave turbulence under the assumption that β is small. We apply our analysis to protons undergoing stochastic heating in the supersonic fast solar wind and obtain proton distributions at heliocentric distances ranging from 4 to 30 solar radii. We find that the proton distribution develops non-Gaussian structure with a flat core and steep tail. For r\gt 5 {R}{{S}}, the proton distribution is well approximated by a modified Moyal distribution. Comparisons with future measurements from Solar Probe Plus could be used to test whether stochastic heating is occurring in the solar-wind acceleration region.


Date: 03/2016 Publisher: The Astrophysical Journal Pages: 47 DOI: 10.3847/0004-637X/820/1/47 Available at: http://stacks.iop.org/0004-637X/820/i=1/a=47?key=crossref.3bba6a0e184137847bf77cde72a2fe1fhttp://stacks.iop.org/0004-637X/820/i=1/a=47/pdfhttp://stacks.iop.org/0004-637X/820/i=1/a=47?key=crossref.3bba6a0e184137847bf77cde72a2fe1f
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2014
Authors: Binias Cindy, Do Van Tu, Jude-Lemeilleur Florence, Plus Martin, Froidefond Jean-Marie, et al.
Title: Environmental factors contributing to the development of brown muscle disease and perkinsosis in Manila clams ( Ruditapes philippinarum ) and trematodiasis in cockles ( Cerastoderma edule ) of Arcachon Bay
Abstract: N/A
Date: 06/2014 Publisher: Marine Ecology Pages: 67 - 77 DOI: 10.1111/maec.2014.35.issue-s110.1111/maec.12087 Available at: http://doi.wiley.com/10.1111/maec.2014.35.issue-s1http://doi.wiley.com/10.1111/maec.12087https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fmaec.12087
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Authors: Balat-Pichelin M., Eck J., Heurtault S., and énat H.
Title: Experimental study of pyrolytic boron nitride at high temperature with and without proton and VUV irradiations
Abstract:

In the frame of future exploration missions such as Solar Probe Plus (NASA) and PHOIBOS (ESA), research was carried out to study pyrolytic BN material envisaged as coating for their heat shields. The physico-chemical behavior of CVD pBN at very high temperature with or without hydrogen ions and VUV (Vacuum Ultra-Violet) irradiations was studied in high vacuum together with the in situ measurement of the thermal radiative properties conditioning the thermal equilibrium of the heat shield. Experimental results obtained on massive pBN samples are presented through in situ mass spectrometry and mass loss rate, and post-test microstructural characterization by XRD, SEM, AFM and nano-indentation techniques, some of them leading to mechanical properties. It could be concluded that synergistic . . .
Date: 09/2014 Publisher: Applied Surface Science Pages: 415 - 425 DOI: 10.1016/j.apsusc.2014.07.007 Available at: https://linkinghub.elsevier.com/retrieve/pii/S0169433214015219https://api.elsevier.com/content/article/PII:S0169433214015219?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0169433214015219?httpAccept=text/plain
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2013
Authors: Reid Hamish A. S., and Kontar Eduard P.
Title: Evolution of the Solar Flare Energetic Electrons in the Inhomogeneous Inner Heliosphere
Abstract:

Solar flare accelerated electrons escaping into the interplanetary space and seen as type III solar radio bursts are often detected near the Earth. Using numerical simulations we consider the evolution of energetic electron spectrum in the inner heliosphere and near the Earth. The role of Langmuir wave generation, heliospheric plasma density fluctuations, and expansion of magnetic field lines on the electron peak flux and fluence spectra is studied to predict the electron properties as could be observed by Solar Orbiter and Solar Probe Plus. Considering various energy loss mechanisms we show that the substantial part of the initial energetic electron energy is lost via wave-plasma processes due to plasma inhomogeneity. For the parameters adopted, the results show that the electron spect. . .
Date: 07/2013 Publisher: Solar Physics Pages: 217 - 232 DOI: 10.1007/s11207-012-0013-x Available at: http://link.springer.com/10.1007/s11207-012-0013-xhttp://link.springer.com/content/pdf/10.1007/s11207-012-0013-x
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2012
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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2011
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: Eck J., Sans J.-L., and Balat-Pichelin M.
Title: Experimental study of carbon materials behavior under high temperature and VUV radiation: Application to Solar Probe+ heat shield
Abstract:

The aim of the Solar Probe Plus (SP+) mission is to understand how the solar corona is heated and how the solar wind is accelerated. To achieve these goals, in situ measurements are necessary and the spacecraft has to approach the Sun as close as 9.5 solar radii. This trajectory induces extreme environmental conditions such as high temperatures and intense Vacuum Ultraviolet radiation (VUV). To protect the measurement and communication instruments, a heat shield constituted of a carbon material is placed on the top of the probe. In this study, the physical and chemical behavior of carbon materials is experimentally investigated under high temperatures (1600-2100 K), high vacuum (10-4 Pa) and VUV radiation in conditions near those at perihelion for SP+. Thanks to several in si. . .
Date: 02/2011 Publisher: Applied Surface Science Pages: 3196 - 3204 DOI: 10.1016/j.apsusc.2010.10.139 Available at: https://linkinghub.elsevier.com/retrieve/pii/S0169433210015059https://api.elsevier.com/content/article/PII:S0169433210015059?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0169433210015059?httpAccept=text/plain
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