A Langmuir probe is a probe used in plasma diagnostics to measure the electron density, electron temperature, and potential of a plasma.
A four-quadrant bipolar power supply is connected to the electrodes in the plasma, and a sinusoidal or triangular voltage is applied. The Langmuir probe method is a method to determine the plasma state by analyzing the swept voltage and current.

The specifications of the bipolar power supply required for plasma measurements depend on the electron temperature, electron density, and potential of the plasma.
Typically, a four-quadrant power supply with a voltage of ±100V, a current of 1-2A, and a frequency of about 100Hz is used. Some of them, such as high-voltage amplifiers ( AMJ series) with a voltage of ±4000 V, may be used.

Langmuir probes are essential for tokamak fusion and are used for EEDF (Electron energy distribution function) measurements in the vacuum vessel.

Related words
  • Plasma
  • Vacuum Plasma Treatment
  • Nuclear fusion
  • Fusion power generation
  • Tokamak
  • Plasma actuator
  • Biconic cusp
  • EEDF
  • vacuum vessel