Energetic electron spectra in Saturn's plasma sheet

2011 ◽  
Vol 116 (A7) ◽  
pp. n/a-n/a ◽  
Author(s):  
J. F. Carbary ◽  
C. Paranicas ◽  
D. G. Mitchell ◽  
S. M. Krimigis ◽  
N. Krupp
Keyword(s):  
Plasma Sheet ◽  
Energetic Electron ◽  
Electron Spectra

scholarly journals Evidence for energetic electron and iondispersive microinjections in theEarth's magnetotail as far as 27 <i>R<sub>E</sub></i>

2004 ◽  
Vol 22 (2) ◽  
pp. 527-535 ◽  
Author(s):  
D. V. Sarafopoulos ◽  
E. T. Sarris ◽  
V. Lutsenko
Keyword(s):  
Time Resolution ◽  
Plasma Sheet ◽  
Energetic Electron ◽  
High Energy ◽  
Ion Fluxes ◽  
Individual Entity ◽  
Boundary Model ◽  
Dispersive Fluxes ◽  
Dispersive Flux

Abstract. High energy and time resolution measurements of energetic electron and ion fluxes obtained by the DOK-2 experiment on board the Interball-tail satellite provide us the opportunity to study the short-lived (1–3min), localized, and often periodic and dispersive flux increases within the plasma sheet. We have deliberately selected and studied two intervals corresponding to the dawn and dusk magnetotail flanks. Dispersive electron (ion) bursts in the dawn side (dusk side) are observed from L=7 to L=27. These bursts, having an individual entity, are termed microinjections and are observed in radial distances greater than those predicted by the ``injection boundary model." In this paper we suggest that the dispersive fluxes at widely separated radial distances are produced by multiple pulsating isospectrum surfaces ordered in succession. At the inner edge of the plasma sheet, the isospectrum surface is considered by Sarafopoulos (2002) as a meandering injection boundary. Roughly, we estimate that the wavelength for an oscillating isospectrum surface is

scholarly journals Magnetic dipolarizations inside geosynchronous orbit with tailward ion flows

2019 ◽  
Vol 37 (3) ◽  
pp. 289-297 ◽  
Author(s):  
Xiaoying Sun ◽  
Weining William Liu ◽  
Suping Duan
Keyword(s):  
Plasma Sheet ◽  
Sharp Increase ◽  
Energetic Electron ◽  
Elevation Angle ◽  
Time History ◽  
Geosynchronous Orbit ◽  
Inner Magnetosphere ◽  
Transfer Path ◽  
New Energy ◽  
History Of

Abstract. Electromagnetic field and plasma data from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) near-Earth probes are used to investigate magnetic dipolarizations inside geosynchronous orbit on 27 August 2014 during an intense substorm with AEmax∼1000 nT. THEMIS-D (TH-D) was located inside geosynchronous orbit around midnight in the interval from 09:25 to 09:55 UT. During this period, two distinct magnetic dipolarizations with tailward ion flows are observed by TH-D. The first one is indicated by the magnetic elevation angle increase from 15 to 25∘ around 09:30:40 UT. The tailward perpendicular velocity is V⊥x∼-50 km s−1. The second one is presented by the elevation angle increase from 25 to 45∘ around 09:36 UT, and the tailward perpendicular velocity is V⊥x∼-70 km s−1. These two significant dipolarizations are accompanied with the sharp increase in the energy flux of energetic electron inside geosynchronous orbit. After a 5 min expansion of the near-Earth plasma sheet (NEPS), THEMIS-E (TH-E) located outside geosynchronous orbit also detected this tailward expanding plasma sheet with ion flows of −150 km s−1. The dipolarization propagates tailward with a speed of −47 km s−1 along a 2.2 RE distance in the X direction between TH-D and TH-E within 5 min. These dipolarizations with tailward ion flows observed inside geosynchronous orbit indicate a new energy transfer path in the inner magnetosphere during substorms.

Substorm Injections as a Source of Relativistic Electrons in Earth’s Outer Radiation Belt

2020 ◽  
Author(s):  
Drew Turner ◽  
Ian Cohen ◽  
Kareem Sorathia ◽  
Sasha Ukhorskiy ◽  
Geoff Reeves ◽  
...  
Keyword(s):  
Phase Space ◽  
Plasma Sheet ◽  
Radiation Belt ◽  
Energetic Electron ◽  
Local Source ◽  
Relativistic Electrons ◽  
Phase Space Density ◽  
Outer Radiation Belt ◽  
Space Density ◽  
Van Allen Probes

&lt;p&gt;Earth&amp;#8217;s magnetotail plasma sheet plays a crucial role in the variability of Earth&amp;#8217;s outer electron radiation belt. Typically, injections of energetic electrons from Earth&amp;#8217;s magnetotail into the outer radiation belt and inner magnetosphere during periods of substorm activity are not observed exceeding ~300 keV. &amp;#160;Consistent with that, phase space density radial distributions of electrons typically indicate that for electrons below ~300 keV, there is a source of electrons in the plasma sheet while for electrons with energies above that, there is a local source within the outer radiation belt itself.&amp;#160; However, here we ask the question: is this always the case or can the plasma sheet provide a direct source of relativistic (&gt; ~500 keV) electrons into Earth&amp;#8217;s outer radiation belt via substorm injection? Using phase space density analysis for fixed values of electron first and second adiabatic invariants, we use energetic electron data from NASA&amp;#8217;s Van Allen Probes and Magnetospheric Multiscale (MMS) missions during periods in which MMS observed energetic electron injections in the plasma sheet while Van Allen Probes concurrently observed injections into the outer radiation belt. We report on cases that indicate there was a sufficient source of up to &gt;1 MeV electrons in the electron injections in the plasma sheet as observed by MMS, yet Van Allen Probes did not see those energies injected inside of geosynchronous orbit.&amp;#160; From global insight with recent test-particle simulations in global, dynamic magnetospheric fields, we offer an explanation for why the highest-energy electrons might not be able to inject into the outer belt even while the lower energy (&lt; ~300 keV) electrons do. Two other intriguing points that we will discuss concerning these results are: i) what acceleration mechanism is capable of producing such abundance of relativistic electrons at such large radial distances (X-GSE &lt; -10 RE) in Earth&amp;#8217;s magnetotail? and ii) during what conditions (if any) might injections of relativistic electrons be able to penetrate into the outer belt?&lt;/p&gt;

Geant4 Modeling of the EPI-Hi Instrument on Parker Solar Probe to Calculate Solar Energetic Electron Spectra

2021 ◽  
Author(s):  
Allan Labrador ◽  
Grant Mitchell ◽  
Eric Christian ◽  
Christina Cohen ◽  
Alan C. Cummings ◽  
...  
Keyword(s):  
Energetic Electron ◽  
Electron Spectra

Energetic electron spectra in the radiation belts

1966 ◽  
Vol 71 (9) ◽  
pp. 2217-2226 ◽  
Author(s):  
J. D. Mihalov ◽  
R. Stephen White
Keyword(s):  
Energetic Electron ◽  
Radiation Belts ◽  
Electron Spectra

Energetic electron signatures in an active magnetotail plasma sheet

2006 ◽  
Vol 38 (8) ◽  
pp. 1608-1614 ◽  
Author(s):  
J.A. Davies ◽  
M.W. Dunlop ◽  
C.H. Perry ◽  
M. Lockwood ◽  
I. Alexeev ◽  
...  
Keyword(s):  
Plasma Sheet ◽  
Energetic Electron

scholarly journals Energetic electron bursts in the plasma sheet and their relation with BBFs

2014 ◽  
Vol 119 (11) ◽  
pp. 8902-8915 ◽  
Author(s):  
A. Y. Duan ◽  
J. B. Cao ◽  
M. Dunlop ◽  
Z. Q. Wang
Keyword(s):  
Plasma Sheet ◽  
Energetic Electron

scholarly journals Contrasting dynamics of electrons and protons in the near-Earth plasma sheet during dipolarization

2018 ◽  
Vol 36 (3) ◽  
pp. 741-760 ◽  
Author(s):  
Andrey Y. Malykhin ◽  
Elena E. Grigorenko ◽  
Elena A. Kronberg ◽  
Rositza Koleva ◽  
Natalia Y. Ganushkina ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Plasma Sheet ◽  
Electron Flux ◽  
Energetic Electron ◽  
Finite Energy ◽  
Transport Processes ◽  
Pile Up ◽  
Combined Action ◽  
Electrostatic Fluctuations ◽  
The Magnetic Field

Abstract. The fortunate location of Cluster and the THEMIS P3 probe in the near-Earth plasma sheet (PS) (at X ∼ −7–−9 RE) allowed for the multipoint analysis of properties and spectra of electron and proton injections. The injections were observed during dipolarization and substorm current wedge formation associated with braking of multiple bursty bulk flows (BBFs). In the course of dipolarization, a gradual growth of the BZ magnetic field lasted ∼ 13 min and it was comprised of several BZ pulses or dipolarization fronts (DFs) with duration ≤ 1 min. Multipoint observations have shown that the beginning of the increase in suprathermal (> 50 keV) electron fluxes – the injection boundary – was observed in the PS simultaneously with the dipolarization onset and it propagated dawnward along with the onset-related DF. The subsequent dynamics of the energetic electron flux was similar to the dynamics of the magnetic field during the dipolarization. Namely, a gradual linear growth of the electron flux occurred simultaneously with the gradual growth of the BZ field, and it was comprised of multiple short (∼ few minutes) electron injections associated with the BZ pulses. This behavior can be explained by the combined action of local betatron acceleration at the BZ pulses and subsequent gradient drifts of electrons in the flux pile up region through the numerous braking and diverting DFs. The nonadiabatic features occasionally observed in the electron spectra during the injections can be due to the electron interactions with high-frequency electromagnetic or electrostatic fluctuations transiently observed in the course of dipolarization. On the contrary, proton injections were detected only in the vicinity of the strongest BZ pulses. The front thickness of these pulses was less than a gyroradius of thermal protons that ensured the nonadiabatic acceleration of protons. Indeed, during the injections in the energy spectra of protons the pronounced bulge was clearly observed in a finite energy range ∼ 70–90 keV. This feature can be explained by the nonadiabatic resonant acceleration of protons by the bursts of the dawn–dusk electric field associated with the BZ pulses. Keywords. Magnetospheric physics (Magnetotail; plasma sheet) – Space plasma physics (Transport processes)

scholarly journals Cluster observations of energetic electron flux variations within the plasma sheet

2009 ◽  
Vol 114 (A11) ◽  
pp. n/a-n/a ◽  
Author(s):  
E. Burin des Roziers ◽  
X. Li ◽  
D. N. Baker ◽  
T. A. Fritz ◽  
R. L. McPherron ◽  
...  
Keyword(s):  
Plasma Sheet ◽  
Electron Flux ◽  
Energetic Electron
Sign in / Sign up

Export Citation Format

Share Document