|Instrument: LEE : Low Energy Electrons|
In Situ/Laboratory Instruments
Instrument Class: Chemical Meters/Analyzers
Instrument Type: LEE
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This experiment provided direct measurements of the energy input into the upper
atmosphere due to electrons and protons in the energy range of 0.2 to 25 keV.
The experiment acquired differential measurements of the energy influx and
angular distribution. There were two detectors measuring electrons and protons
from 0.2 to 25 keV in 16 logarithmically spaced steps, and one detector
measuring 5 keV electrons continuously. Each detector consisted of a
cylindrical electrostatic analyzer for species and energy selection, and a
Spiraltron electron multiplier for particle detection. Energy distributions
were obtained by applying different fixed or stepped voltages to the deflection
plates. Distributions in angle were measured using the spacecraft spin and the
analyzers' positions on the spacecraft. In the despun modes, measurements were
obtained at 45 deg to the spacecraft equator, and radially away from the earth.
Detector look angles were chosen to give optimum magnetic pitch-angle coverage
when the spacecraft was moving either poleward or equatorward. All detectors
were identical in construction and used 1- x 6-mm entrance apertures. Counts
were accumulated over 55.7 ms and read out each main telemetry frame (62.5 ms).
The two stepped detectors moved one energy step once each main frame with the
same accumulation time, requiring about 1 s for a complete cycle of steps. More
complete details of this experiment may be found in R. A. Hoffman et al., Radio
Sci., v. 8, n. 4, p. 393, 1973. NSSDC has all the useful data that exist from
this investigation. The LEE experiment was conducted on the AE-C spacecraft.