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private:writeups:plasmaimpedanceprobes [2020/07/01 19:59]
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private:writeups:plasmaimpedanceprobes [2020/07/02 14:17] (current)
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   - Plasma frequency [Blackwell2005]   - Plasma frequency [Blackwell2005]
   - Electron density (by measuring plasma frequency) [Blackwell2005]   - Electron density (by measuring plasma frequency) [Blackwell2005]
 +  - Plasma potential
 +  - Collision frequency
  
 === Methods === === Methods ===
  
-  - Actively driven RF sweeps [Blackwell2005].  Relate the peaks and zero intercepts of Re(Z) and Im(Z) to circuit models to get the plasma frequency. +PIPs can be operated in a number of methods
-  - Plasma oscillation (excite a two stream instability) [Blackwell2005].  Drive weak beam of electrons into the plasma to excite a two stream instability.  It's frequency is close to the plasma frequency.  An FFT of passive PIP measurements reveals the frequency.  +
  
 +  - Actively driven RF sweeps [Blackwell2005].  Relate the peaks and zero intercepts of Re(Z) and Im(Z) to circuit models and dispersion relationships to get the plasma frequency.
 +  - Plasma oscillation (excite a two stream instability) [Blackwell2005].  Drive weak beam of electrons into the plasma to excite a two stream instability.  Under correct conditions, its frequency is close to the plasma frequency.  An FFT of passive PIP measurements reveals the frequency.  
  
-=== Advantages/disadvantages ===+ 
 +=== Advantages ===
  
   * [Blackwell2005] An improvement over Langmuir probes because contamination of the probe has a larger impact on its measurements than on the PIP.   * [Blackwell2005] An improvement over Langmuir probes because contamination of the probe has a larger impact on its measurements than on the PIP.
 +  * Better resolution and accuracy than traditional Langmuir probes [citation]
 +
 +=== Disadvantages ===
 +
 +  * More complicated.  Requires careful setup/calibration and the use of an expensive network analyzer.
 +  * (Check this) Cannot be used in real-time because the network analyzer data can only be post-processed.  
  
 === Sources of error === === Sources of error ===
private/writeups/plasmaimpedanceprobes.1593633551.txt.gz · Last modified: 2020/07/01 19:59 by admin