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dc.contributor.authorLongley, William J.en_US
dc.contributor.authorOppenheim, Meers M.en_US
dc.contributor.authorFletcher, Alex C.en_US
dc.contributor.authorDimant, Yakov S.en_US
dc.date.accessioned2020-04-22T12:42:03Z
dc.date.available2020-04-22T12:42:03Z
dc.date.issued2018-04-01
dc.identifierhttp://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000433498400034&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=6e74115fe3da270499c3d65c9b17d654
dc.identifier.citationWilliam J Longley, Meers M Oppenheim, Alex C Fletcher, Yakov S Dimant. 2018. "ISR Spectra Simulations With Electron-Ion Coulomb Collisions." JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Volume 123, Issue 4, pp. 2990 - 3004 (15). https://doi.org/10.1002/2017JA025015
dc.identifier.issn2169-9380
dc.identifier.issn2169-9402
dc.identifier.urihttps://hdl.handle.net/2144/40274
dc.description.abstractIncoherent scatter radars (ISR) rely on Thomson scattering of very high frequency or ultrahigh frequency radio waves off electrons in the ionosphere and measure the backscattered power spectra in order to estimate altitude profiles of plasma density, electron temperature, ion temperature, and ion drift speed. These spectra result from the collective behavior of coupled ion and electron dynamics, and, for most cases, existing theories predict these well. However, when the radar points nearly perpendicular to the Earth's magnetic field, the motion of the plasma across the field lines becomes complex and Coulomb collisions between electrons and ions become important in interpreting ISR measurements. This paper presents the first fully kinetic, self‐consistent, particle‐in‐cell simulations of ISR spectra with electron‐ion Coulomb collisions. We implement a grid‐based Coulomb collision algorithm in the Electrostatic Parallel Particle‐in‐Cell simulator and obtain ISR spectra from simulations both with and without collisions. For radar directions greater than 5° away from perpendicular to the magnetic field, both sets of simulations match collisionless ISR theory well. For angles between 3° and 5°, the collisional simulation is well described by a simplified Brownian motion collision process. At angles less than 3° away from perpendicular the Brownian motion model fails, and the collisional simulation qualitatively agrees with previous single particle simulations. For radar directions exactly perpendicular to the magnetic field the simulated collisional spectra match those from the Brownian motion collision theory, in agreement with previous single particle simulations.en_US
dc.description.sponsorshipThis work was supported by NASA grants NNX14AI13G and NNX16AB80G and NSF grant PHY-1500439. This work used the XSEDE and TACC computational facilities, supported by NSF grant ACI-1053575. The work by Alex Fletcher was supported by NSF-AGS Postdoctoral Research Fellowship award 1433536 while at the Center for Space Physics, Boston University. Simulation produced data are archived at TACC and are available upon request. We thank John Swoboda of MIT Haystack Observatory for his suggestions on processing the simulated ISR spectra. (NNX14AI13G - NASA; NNX16AB80G - NASA; PHY-1500439 - NSF; ACI-1053575 - NSF; 1433536 - NSF-AGS Postdoctoral Research Fellowship at the Center for Space Physics, Boston University)en_US
dc.format.extentp. 2990 - 3004en_US
dc.languageEnglish
dc.language.isoen_US
dc.publisherAMER GEOPHYSICAL UNIONen_US
dc.relation.ispartofJOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
dc.subjectScience & technologyen_US
dc.subjectPhysical sciencesen_US
dc.subjectAstronomy & astrophysicsen_US
dc.subjectincoherent scatteren_US
dc.subjectJicamarcaen_US
dc.subjectCoulomb collisionsen_US
dc.subjectParticle-in-cellen_US
dc.subjectPerpendicular spectraen_US
dc.subjectIncoherent-scatter spectrumen_US
dc.subjectF-regionen_US
dc.subjectModelen_US
dc.subjectTemperatureen_US
dc.subjectDensityen_US
dc.subjectPlasmasen_US
dc.subjectRadarsen_US
dc.titleISR spectra simulations with electron-ion Coulomb collisionsen_US
dc.typeArticleen_US
dc.description.versionFirst author draften_US
dc.identifier.doi10.1002/2017JA025015
pubs.elements-sourceweb-of-scienceen_US
pubs.notesEmbargo: Not knownen_US
pubs.organisational-groupBoston Universityen_US
pubs.organisational-groupBoston University, College of Arts & Sciencesen_US
pubs.organisational-groupBoston University, College of Arts & Sciences, Department of Astronomyen_US
pubs.publication-statusPublisheden_US
dc.identifier.orcid0000-0002-8581-6177 (Oppenheim, Meers M)
dc.identifier.mycv391960


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