Space Plasmas

                                                The Terrestrial Ionosphere                                        Reentry Plasmas

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The Terrestrial Ionosphere

Space Lab’s interests include investigating the processes and unique phenomena of the terrestrial ionosphere through in situ measurements correlated with common volume measurements by ground based radar and lidar. Space Lab® can develop your plasma diagnostic suite to include Langmuir probes, impedance probes, solid-state energetic particle detectors, or a photoionization stimulus system.  The electrometers developed utilize radiation hardened parts and may be used for deep space operation.

Terrestrial ionosphere plasma ranges include the day or night time D-region to F-region for use on sounding rockets or satellites.
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Langmuir Probes

• Fixed and Swept bias implementations to determine:

          -Electron Density
          -Ion Density
          -Electron Temperature
          -Plasma Potential

• Optimized Probe Design

          -Reduced photoelectric effect
          -Low Lorentz force effects
          -Surface contamination mitigation
          -Minimized collector edge effects

• Low noise electrometer design (resolution ~1 pA)

Impedance Probes

• ​Multiple stimulus modes and functions to determine:

          -Electron Density
          -Electron-Neutral Collision Frequency

• Capable of combining with Langmuir probe functions

Probe Design

Langmuir Probe Specifications.

Electrometer

Probe and Radar Measurements (probe measurements with direct calculation from Langmuir theory - no shifting in potential necessary)

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Reentry Plasmas

Understanding the plasma environment around hypersonic vehicles is necessary to mitigate the communications blackout that has occurred around all such vehicles, since the first hypersonic flight in 1949.  Space Lab® is currently investigating a new impedance probe technique to monitor the highly collisional spacecraft reentry plasmas.  The new instrument is called the Hypersonic Plasma Diagnostic Instrument (HPDI).  The HPDI determines the plasma parameters:​

• Electron density
• Electron-neutral collision frequency
• Electron temperature
• Plasma layer profile

The HPDI is non-invasive and installed under the thermal protection system (TPS).  This new technique may be used for other types of plasmas as well.  Hypersonic plasmas are not affected by the geomagnetic field, where the cyclotron resonance is much less than the electron plasma frequency and electron-neutral collision frequency.

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