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Langmuir Probe and Waves (LPW)

Langmuir Probe and Waves (LPW)

Langmuir probe and waves-Extreme Ultraviolet Instruments
The LPW instrument measures thermal electron density and temperature and the Extreme Ultraviolet sensor (inset) measures solar input across three channels. (Courtesy LASP)

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:

Shown here are the two stacer booms that deployed the MAVEN Langmuir Probe and Waves instruments on October 9, 2014. (Courtesy LASP)
Shown here are the two stacer booms that deployed the MAVEN Langmuir Probe and Waves instruments on October 9, 2014. (Courtesy LASP)

  • 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 fo=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 5000oK
  • Heritage from THEMIS and RBSP

Instrument publications:

Bob Ergun—LPW Instrument Lead
Bob Ergun—LPW Instrument Lead

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

 

 

 

 

 


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

LPW presentation (5.4 MB PDF)
LPW presentation
(5.4 MB PDF)
EUV presentation (6.5 MB PDF)
EUV presentation
(6.5 MB PDF)