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Spacecraft surface charging within geosynchronous orbit observed by the Van Allen Probes.

Sarno-Smith LK, Larsen BA, Skoug RM, Liemohn MW, Breneman A, Wygant JR, Thomsen MF - Space Weather (2016)

Bottom Line: We present statistical results on spacecraft charging within geosynchronous orbit by L and MLT.An algorithm to extract the H(+) charging line in the HOPE instrument data was developed to better explore intense charging events.Also, this study explored how spacecraft potential relates to electron number density, electron pressure, electron temperature, thermal electron current, and low-energy ion density between 1 and 210 eV.

View Article: PubMed Central - PubMed

Affiliation: Department of Climate and Space Engineering University of Michigan Ann Arbor Michigan USA.

ABSTRACT

Using the Helium Oxygen Proton Electron (HOPE) and Electric Field and Waves (EFW) instruments from the Van Allen Probes, we explored the relationship between electron energy fluxes in the eV and keV ranges and spacecraft surface charging. We present statistical results on spacecraft charging within geosynchronous orbit by L and MLT. An algorithm to extract the H(+) charging line in the HOPE instrument data was developed to better explore intense charging events. Also, this study explored how spacecraft potential relates to electron number density, electron pressure, electron temperature, thermal electron current, and low-energy ion density between 1 and 210 eV. It is demonstrated that it is imperative to use both EFW potential measurements and the HOPE instrument ion charging line for examining times of extreme spacecraft charging of the Van Allen Probes. The results of this study show that elevated electron energy fluxes and high-electron pressures are present during times of spacecraft charging but these same conditions may also occur during noncharging times. We also show noneclipse significant negative charging events on the Van Allen Probes.

No MeSH data available.


Related in: MedlinePlus

(a) The number of EFW charging events from February 2013 to April 2015 over the range of −200 V to 50 V in 10 V windows. The x axis labels give the lower bound for each window. An occurrence is defined a single measurement by EFW over an 11 s window. (b) The negative spacecraft potential recorded by EFW over the February 2013 to April 2015 time period.
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swe20312-fig-0001: (a) The number of EFW charging events from February 2013 to April 2015 over the range of −200 V to 50 V in 10 V windows. The x axis labels give the lower bound for each window. An occurrence is defined a single measurement by EFW over an 11 s window. (b) The negative spacecraft potential recorded by EFW over the February 2013 to April 2015 time period.

Mentions: Figure 1 shows the distribution of charging occurrences and magnitudes in the Van Allen Probes EFW measurements from February 2013 to April 2015. Combining EFW data from both Van Allen Probes A and B satellites, Figure 1a shows that each satellite usually charged within ±10 V during this time period. Charging events less than −50 V occurred 4 orders of magnitude less often than ±10 V charging times. Figure 1b highlights that most of the negative charging events throughout the mission occurred in the first 4 months of 2013 and from August to December of 2014, when the apogee of the satellites was in the postmidnight sector.


Spacecraft surface charging within geosynchronous orbit observed by the Van Allen Probes.

Sarno-Smith LK, Larsen BA, Skoug RM, Liemohn MW, Breneman A, Wygant JR, Thomsen MF - Space Weather (2016)

(a) The number of EFW charging events from February 2013 to April 2015 over the range of −200 V to 50 V in 10 V windows. The x axis labels give the lower bound for each window. An occurrence is defined a single measurement by EFW over an 11 s window. (b) The negative spacecraft potential recorded by EFW over the February 2013 to April 2015 time period.
© Copyright Policy - creativeCommonsBy-nc-nd
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4933096&req=5

swe20312-fig-0001: (a) The number of EFW charging events from February 2013 to April 2015 over the range of −200 V to 50 V in 10 V windows. The x axis labels give the lower bound for each window. An occurrence is defined a single measurement by EFW over an 11 s window. (b) The negative spacecraft potential recorded by EFW over the February 2013 to April 2015 time period.
Mentions: Figure 1 shows the distribution of charging occurrences and magnitudes in the Van Allen Probes EFW measurements from February 2013 to April 2015. Combining EFW data from both Van Allen Probes A and B satellites, Figure 1a shows that each satellite usually charged within ±10 V during this time period. Charging events less than −50 V occurred 4 orders of magnitude less often than ±10 V charging times. Figure 1b highlights that most of the negative charging events throughout the mission occurred in the first 4 months of 2013 and from August to December of 2014, when the apogee of the satellites was in the postmidnight sector.

Bottom Line: We present statistical results on spacecraft charging within geosynchronous orbit by L and MLT.An algorithm to extract the H(+) charging line in the HOPE instrument data was developed to better explore intense charging events.Also, this study explored how spacecraft potential relates to electron number density, electron pressure, electron temperature, thermal electron current, and low-energy ion density between 1 and 210 eV.

View Article: PubMed Central - PubMed

Affiliation: Department of Climate and Space Engineering University of Michigan Ann Arbor Michigan USA.

ABSTRACT

Using the Helium Oxygen Proton Electron (HOPE) and Electric Field and Waves (EFW) instruments from the Van Allen Probes, we explored the relationship between electron energy fluxes in the eV and keV ranges and spacecraft surface charging. We present statistical results on spacecraft charging within geosynchronous orbit by L and MLT. An algorithm to extract the H(+) charging line in the HOPE instrument data was developed to better explore intense charging events. Also, this study explored how spacecraft potential relates to electron number density, electron pressure, electron temperature, thermal electron current, and low-energy ion density between 1 and 210 eV. It is demonstrated that it is imperative to use both EFW potential measurements and the HOPE instrument ion charging line for examining times of extreme spacecraft charging of the Van Allen Probes. The results of this study show that elevated electron energy fluxes and high-electron pressures are present during times of spacecraft charging but these same conditions may also occur during noncharging times. We also show noneclipse significant negative charging events on the Van Allen Probes.

No MeSH data available.


Related in: MedlinePlus