Depending upon the simulation there are test cases that have analytical solutions that can be compared to. Sadly, the most common test is to take experimental data and compare. I say sadly because the limited shot rate and the ability of diagnostics to resolve all the key parameters is limited. My observation of high density plasma simulation codes on devices like plasma foci is to keep patching the code until it gives you the same answer as the experiments within reason. Even after these comparisons, the codes don’t always conserve all the necessary parameters like momentum, energy and mass.
