Found 16 results
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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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1973
Authors: Plus émi
Title: Étude par spectroscopie infrarouge des composés Mg(NH 3 ) 6 Cl 2 et Mg(ND 3 ) 6 Cl 2
Abstract:

The infrared spectra of pure Mg(NH3)6Cl2 and Mg(ND3)6Cl2 were recorded from 4 000 to 50 cm-1 at 40 and — 180 °C. The observed bands are assigned. The hydrogenated compound was studied by differential thermal analysis.

The observed infrared spectral data are compared with the previously reported experimental values for other divalent metals (Co2+, Ni2+, Fe2+, Mn2+). This comparison proves that (he coordination bond is stronger for Mg than for the other metals.


Date: 01/1973 Publisher: Journal de Chimie Physique Pages: 900 - 904 DOI: 10.1051/jcp/1973700900 Available at: http://jcp.edpsciences.org/10.1051/jcp/1973700900http://jcp.edpsciences.org/10.1051/jcp/1973700900/pdf
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Authors: Plus émi
Title: Étude vibrationnelle de complexes du magnesium. Spectroscopie Raman de Mg(NH3)6Cl2et Mg(ND3)6Cl2
Abstract:

L'auteur a pu obtenir les fréquences des vibrations actives en diffusion Raman du chlorure de magnésium hexa‐amminé hydrogéné et deutérié à l'état cristallisé. Toutes les vibrations attendues ont pu être observées pour la première fois pour un composé de ce type (vibrations internes et vibrations externes). L'attribution de toutes les bandes du spectre est proposée. Ces résultats, rapprochés de ceux obtenus par spectroscopie infrarouge, permettent de connaître la structure vibrationnelle complète du complexe. L'éclatement de certaines vibrations montre que les coordinats ne sont pas en rotation libre et que leur orientation donne à l'ion complexe la symétrie du groupe ponctuel D3d.


Date: 12/1973 Publisher: Journal of Raman Spectroscopy Pages: 551 - 563 DOI: 10.1002/jrs.v1:610.1002/jrs.1250010605 Available at: https://onlinelibrary.wiley.com/doi/abs/10.1002/jrs.1250010605
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