Langmuir probes have been installed on satellites and sounding rockets to observe the general characteristics of thermal plasma in the ionosphere for more than five decades. Because of its simplicity and convenience, the Langmuir probe is one of the most frequently installed scientific instruments on spacecraft. While the algorithm to estimate the temperature and number density of thermal elect...

INTRODUCTION: The Langmuir probe is a diagnostic device used to determine several basic properties of a plasma, such as temperature and density. A plasma is a state of matter which contains enough free (not bound to an atom) charged particles (electrons and ions) so that its dynamical behavior is dominated by electromagnetic forces. The subject of plasma physics is concerned mainly with ionized...

I give several simple examples of model Langmuir probe current-voltage I-V characteristics that help students learn how to interpret real I-V characteristics obtained in a plasma. Students can also create their own Langmuir probe I-V characteristics using a program with the plasma density, plasma potential, electron temperature, ion temperature, and probe area as input parameters. Some examples...

The finite, electrostatically achievable, temporal resolution of plasma properties from a turbulent discharge is limited by an array of effects wherein the theory of Langmuir probes breaks down. Formulations for the particle transit time, sheath formation time, plasma-probe resonance, polarization current, sheath capacitance, stray capacitance, and mutual capacitance effects are all evaluated f...

In an effort to temporally resolve the electron density, electron temperature, and plasma potential for turbulent plasma discharges, a unique high-speed dual Langmuir probe (HDLP) has been developed. A traditional single Langmuir probe of cylindrical geometry (exposed to the plasma) is swept simultaneously with a nearby capacitance and noise compensating null probe (fully insulated from the pla...

A simple method for measuring RF plasma parameters by means of a DC-biased Langmuir probe is developed. The object of this paper is to ensure the reliability of this method by using the other methods with different principles. First, Langmuir probe current e I response on RF voltage p1 V superimposed to DC p V biased probe was examined in DC plasmas. Next, probe current response of DC biased pr...