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Langmuir probe data analysis code

version 1.2 (87.5 KB) by aasim Azooz
four parameters fitting of Langmuir I-V probe data


Updated 28 Nov 2015

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A computer code for plasma Langmuir probe analysis is presented here. The code uses a four parameters fitting method to deduce plasma properties including the ion and electron saturation currents, plasma potential, plasma electron temperature, the electron energy distribution function EEDF. Full simple instructions are given in the pdf file. No need of prior knowledge of MATLAB programming is assumed. The code is compatible with any MATLAB version. If you are working in plasma physics, please give me your feedback

Cite As

aasim Azooz (2020). Langmuir probe data analysis code (, MATLAB Central File Exchange. Retrieved .

Comments and Ratings (13)

the work is good but it gives unrealistic values for my data.

How can i used this code to read my CSV data file?

Niaz Wali

I need to calculate an electron density and electron temperature by using triple Langmuir probes. Would someone like to help me?


Dear Dr. Azooz, in your program you give (a) values 1,5,-5,0. Why you put that values ?


I realized I never rated this one- sorry! I love this submission, Prof. Azooz, thank you!


Appears to work in R2011b if you merely take the transpose of one of the input matrices (I transposed "I" for the example code). The fit function requires matching sizes, with them opposing each other, the code does not complete.


Moving "end" to the end of the function, I get the following error for fitting:

??? Error using ==> nlinfit at 126
MODELFUN should return a vector of fitted values the same length as Y.

Error in ==> Analyze_Langmuir2 at 16


The example code produces the following error:

??? Error: File: Analyze_Langmuir.m Line: 80 Column: 1
This statement is not inside any function.
(It follows the END that terminates the definition of the function

using Matlab R2011a

Qais Algwari

It is an excellent work. I hope from Dr.Azooz do develop this work to be a full automatic EEDF calculation. I means to calculate the plasma potention computerized. I think it is easy do that.

Ying Wu

Software is user friendly, and author is very quick to respond to emails. I feel there should be an added option to enter in the probe area so that the plasma density can be calculated as well.



This update allows the software to work smoothly on higher matlab versions

The updated software now does more thing in automatic way it also calculates the electron and ion saturation currents, the plasma potential, the flouting potential, the ion and electron number densities, and the plasma electron temperature

correcting a small bug in langmuir111

MATLAB Release Compatibility
Created with R13
Compatible with any release
Platform Compatibility
Windows macOS Linux