Using Electron Phase Space Density Signatures to Identify the Electromagnetic Waves Responsible for Accelerating Relativistic Electrons in Earth's Magnetosphere

2006 ◽  
pp. 225-237 ◽  
Author(s):  
J. C. Green
Keyword(s):  
Phase Space ◽  
Electromagnetic Waves ◽  
Relativistic Electrons ◽  
Phase Space Density ◽  
Space Density ◽  
Earth’S Magnetosphere ◽  
Earth's Magnetosphere

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

<p>Earth’s magnetotail plasma sheet plays a crucial role in the variability of Earth’s outer electron radiation belt. Typically, injections of energetic electrons from Earth’s magnetotail into the outer radiation belt and inner magnetosphere during periods of substorm activity are not observed exceeding ~300 keV.  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.  However, here we ask the question: is this always the case or can the plasma sheet provide a direct source of relativistic (> ~500 keV) electrons into Earth’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’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 >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.  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 (< ~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 < -10 RE) in Earth’s magnetotail? and ii) during what conditions (if any) might injections of relativistic electrons be able to penetrate into the outer belt?</p>

Phase Space Density matching of relativistic electrons using the Van Allen Probes: REPT results

2013 ◽  
Vol 40 (18) ◽  
pp. 4798-4802 ◽  
Author(s):  
S. K. Morley ◽  
M. G. Henderson ◽  
G. D. Reeves ◽  
R. H. W. Friedel ◽  
D. N. Baker
Keyword(s):  
Phase Space ◽  
Relativistic Electrons ◽  
Phase Space Density ◽  
Space Density ◽  
Van Allen Probes

scholarly journals Gradual diffusion and punctuated phase space density enhancements of highly relativistic electrons: Van Allen Probes observations

2014 ◽  
Vol 41 (5) ◽  
pp. 1351-1358 ◽  
Author(s):  
D. N. Baker ◽  
A. N. Jaynes ◽  
X. Li ◽  
M. G. Henderson ◽  
S. G. Kanekal ◽  
...  
Keyword(s):  
Phase Space ◽  
Relativistic Electrons ◽  
Phase Space Density ◽  
Space Density ◽  
Van Allen Probes

scholarly journals Features of energetic particle radial profiles inferred from geosynchronous responses to solar wind dynamic pressure enhancements

2009 ◽  
Vol 27 (2) ◽  
pp. 851-859 ◽  
Author(s):  
Y. Shi ◽  
E. Zesta ◽  
L. R. Lyons
Keyword(s):  
Magnetic Field ◽  
Phase Space ◽  
Dynamic Pressure ◽  
Radial Profile ◽  
Radial Distance ◽  
Geosynchronous Orbit ◽  
Relativistic Electrons ◽  
Phase Space Density ◽  
Space Density ◽  
Flux Response

Abstract. Determination of the radial profile of phase space density of relativistic electrons at constant adiabatic invariants is crucial for identifying the source for them within the outer radiation belt. The commonly used method is to convert flux observed at fixed energy to phase space density at constant first, second and third adiabatic invariants, which requires an empirical global magnetic field model and thus might produce some uncertainties in the final results. From a different perspective, in this paper we indirectly infer the shape of the radial profile of phase space density of relativistic electrons near the geosynchronous region by statistically examining the geosynchronous energetic flux response to 128 solar wind dynamic pressure enhancements during the years 2000 to 2003. We thus avoid the disadvantage of using empirical magnetic field models. Our results show that the flux response is species and energy dependent. For protons and low-energy electrons, the primary response to magnetospheric compression is an increase in flux at geosynchronous orbit. For relativistic electrons, the dominant response is a decrease in flux, which implies that the phase space density decreases toward increasing radial distance at geosynchronous orbit and leads to a local peak inside of geosynchronous orbit. The flux response of protons and non-relativistic electrons could result from a phase density that increases toward increasing radial distance, but this cannot be determined for sure due to the particle energization associated with pressure enhancements. Our results for relativistic electrons are consistent with previous results obtained using magnetic field models, thus providing additional confirmation that these results are correct and indicating that they are not the result of errors in their selected magnetic field model.

scholarly journals Cooling of Sr to high phase-space density by laser and sympathetic cooling in isotopic mixtures

2006 ◽  
Vol 73 (2) ◽  
Author(s):  
G. Ferrari ◽  
R. E. Drullinger ◽  
N. Poli ◽  
F. Sorrentino ◽  
G. M. Tino
Keyword(s):  
Phase Space ◽  
Phase Space Density ◽  
Sympathetic Cooling ◽  
Space Density ◽  
High Phase

scholarly journals Comparison of energetic electron flux and phase space density in the magnetosheath and in the magnetosphere

2012 ◽  
Vol 117 (A5) ◽  
pp. n/a-n/a ◽  
Author(s):  
Bingxian Luo ◽  
Xinlin Li ◽  
Weichao Tu ◽  
Jiancun Gong ◽  
Siqing Liu
Keyword(s):  
Phase Space ◽  
Electron Flux ◽  
Energetic Electron ◽  
Phase Space Density ◽  
Space Density

scholarly journals Phase-space density in heavy-ion collisions revisited

2003 ◽  
Vol 30 (4) ◽  
pp. 517-523 ◽  
Author(s):  
Q. H. Zhang ◽  
J. Barrette ◽  
C. Gale
Keyword(s):  
Phase Space ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Phase Space Density ◽  
Space Density ◽  
Ion Collisions

Phase space density analysis of outer radiation belt electron energization and loss during geoeffective and non-geoeffective sheath regions

2021 ◽  
Author(s):  
Milla Kalliokoski ◽  
Emilia Kilpua ◽  
Adnane Osmane ◽  
Allison Jaynes ◽  
Drew Turner ◽  
...  
Keyword(s):  
Phase Space ◽  
Energetic Electron ◽  
Electron Content ◽  
Phase Space Density ◽  
Geomagnetic Disturbances ◽  
Interplanetary Coronal Mass Ejections ◽  
Outer Radiation Belt ◽  
Space Density ◽  
Sheath Region ◽  
Chorus Waves

<p>The energetic electron content in the Van Allen radiation belts surrounding the Earth can vary dramatically on timescales from minutes to days, and these electrons present a hazard for spacecraft traversing the belts. The outer belt response to solar wind driving is however yet largely unpredictable. Here we investigate the driving of the belts by sheath regions preceding interplanetary coronal mass ejections. Electron dynamics in the belts is governed by various competing acceleration, transport and loss processes. We analyzed electron phase space density to compare the energization and loss mechanisms during a geoeffective and a non-geoeffective sheath region. These two case studies indicate that ULF-driven inward and outward radial transport, together with the incursions of the magnetopause, play a key role in causing the outer belt electron flux variations. Chorus waves also likely contribute to energization during the geoeffective event. A global picture of the wave activity is achieved through a chorus proxy utilizing POES measurements. We highlight that also the non-geoeffective sheath presented distinct changes in outer belt electron fluxes, which is also evidenced by our statistical study of outer belt electron fluxes during sheath events. While not as intense as during geoeffective sheaths, significant changes in outer belt electron fluxes occur also during sheaths that do not cause major geomagnetic disturbances.</p>

scholarly journals NIHAO project II: halo shape, phase-space density and velocity distribution of dark matter in galaxy formation simulations

2016 ◽  
Vol 462 (1) ◽  
pp. 663-680 ◽  
Author(s):  
Iryna Butsky ◽  
Andrea V. Macciò ◽  
Aaron A. Dutton ◽  
Liang Wang ◽  
Aura Obreja ◽  
...  
Keyword(s):  
Dark Matter ◽  
Phase Space ◽  
Velocity Distribution ◽  
Galaxy Formation ◽  
Phase Space Density ◽  
Space Density
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