computeDebyeLength.py

This analyzer script generates particle number density, temperature (K) and Debye length, and creates a dataset for visualization containing the fraction of Debye length occupied by each mesh cell, based on the data in particle files. The analyzer is implemented for 2D-Cylindrical and Cartesian coordinate systems, e.g. ZR and XY. Before running this analyzer one must compute the kinetic energy of the particles by executing addPtclComponentKEeV.py and deselect “outputXcomponent”, “outputYcomponent”, and “outputZcomponent”.

-s <simname>, --simulationName=<simname>

(string, required)

<simname> is the name of the simulation to be analyzed. The file extension should NOT be included in this text field.

-S <spname>, --speciesName=<spname>

(string, required)

<spname> is the name of the electron species for which particle number density to be calculated. If there is more than one electron species, the calculation may not be valid.

-Z, --compMajorC

(flag)

The indexing order for written datasets. If checked, use “compMajorC”. If unchecked, use the default “compMinorC”

-w, --overwrite

(flag)

Whether a dataset or group should be overwritten if it already exists.

Output

This analyzer script outputs particle number density (\(/m^{3}\)), temperature (\(T={{3\over{2}}\cdot{k}_{B}}\)), and the ratio of debye length measured in the units of the maximum grid dimension at that point (\(D=\lambda_{D}/\Delta{x}\)). All data is output as VizSchema compliant fields visualizable in Composer. A high value, greater than 10, is an indication that the Debye length is well resolved. A value less than 1 means that the Debye length is not resolved, and is an indication that particles in the simulation are likely to artificially heat. Some mitigation is possible with higher order particles but normally the best solution is to increase the grid resolution. These density fields can help to analyze the particle distribution results in the simulation domain.

If you are running this analyzer from the UI, and the output dataset file already exists, then it will be overwritten each time the analyzer is run, unless you uncheck the Overwrite Existing Files box near the bottom of the Analysis Results pane.

If you are running the analyzer from the command line, the dataset will not be overwritten unless the -w, or --overwrite flag is specified on the command line.

The results of your analyzer may not be written into the output file if you have not specified the overwrite option to be True.