Langmuir Probe and Waves (LPW)

The Langmuir Probe and Waves (LPW) instrument is part of the Particles and Fields (P & F) Package and determines ionospheric properties, wave heating of the upper atmosphere, and solar EUV input to the atmosphere.

Goals:

• Measure the in situ electron density and electron temperature from the ionospheric peak up to the nominal ionopause location; measure the electric field wave power important for ion heating
• Characterize the basic state of the ionosphere—its global structure, variability, and thermal properties
• Determine the effects of solar wind generated plasma waves and auroral precipitation on ionosphere heating and relationship to plasma escape
• Determine the electron temperatures required for deriving ion recombination rates and ionospheric chemistry
• Identify the ionopause and detached, escaping ionosphere clouds

Observations:

• Electron temperature and number density throughout upper atmosphere
• Electric field wave power at low frequencies important for ion heating
• Wave spectra of naturally emitted and actively stimulated Langmuir waves to calibrate density measurements

Technical details and heritage:

• Cylindrical sensors on two 7-meter booms
• Sensor I-V sweeps (at least ±50 V range)
• Low frequency (f: 0.05-10 Hz) E-field power; sensitivity 10^-8 (V/m)²/Hz (f₀/f)² where f_o=10 Hz and 100% bandwidth
• E-Spectra measurements up to 2 MHz
• White noise (50 kHz – 2 MHz ) sounding
• Thermal Electron density 100 to 106 cm^-3
• Electron temperatures 500 to 5000^oK
• Heritage from THEMIS and RBSP

Instrument publications:

• Ionospheric plasma density variations observed at Mars by MAVEN/LPW
  (Geophysical Research Letters article—published online November 2015)—Download PDF (1 MB)
• The Langmuir Probe and Waves (LPW) Instrument for MAVEN
  (Space Science Reviews article—published online September 2015)—Download PDF (4 MB)

Bob Ergun (LASP) is the instrument lead for the LPW.

 

 

 

 

 

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MAVEN Science Community Workshop Presentations
(Dec. 2, 2012)