Helpful info for running GS2

For the beginnings of detailed, module-by-module documentation, try looking here.

Gyrokinetic equations

The basic equations and some references may be found here .
Kotschenreuther's algorithms for the original linear version of GS2 are here.

Slides from Training Presentation

   Gyrokinetic basics
   GS2 velocity space
   Linear How-To (not really...)
   Nonlinear issues
   Sixth part
   Ernst talk
   eighth part
   Ninth part
   Tenth part
   Twelfth part


Newer and older input files with lots of comments are posted. See this section of the website for the most recent documentation of the input decks in HTML format.

Input file consistency        --- New!

There is a code called ingen in the distribution which reads a gs2 input file, does many consistency checks, looks for errors, and produces a report ( The report includes recommendations for the number of processors, runtime estimates for some platforms, and a summary of what the input file is set up to do.

Seaborg batch script

A sample Load Leveler script for running on is available. Replace runname with your run name, put in the appropriate email address, choose the number of nodes correctly, and submit in the directory with the executable and the file with the command "llqs runname.llq".

Collision operator

A postcript file discussing the collision operator is available. (PDF)

Choosing the number of processors and nodes

A short discussion of how to choose an appropriate number of processors on seaborg is also available. Ideally, users should use the recommendations from ingen. There are also some notes about the implementation of parallelism in GS2 posted.

Pitch angle and energy grids

Some notes about the allowable values of nesub, nesuper and ngauss may be found here. Again, the report produced by ingen includes relevant comments.

Quick plots with gnuplot

The output files called runname.fields and runname.eigenfunc can be used to make quick plots with a program like gnuplot. Show me how.


The quantity phtot that is printed in the output is proportional to a sum of |phi|^2 integrated over the eigenfunction.

Running on an O2k

Here are some brief notes about running on the Origin-2000 at Princeton,