His particle equations are normalized
slightly different to ours, as in equation 2 of the attached paper.
That ensures that the unit of time is always 1 Larmor period.
This saves us having to work out the Larmor time for evaluation of the
pitch angle diffusion (as is done in the Thesis chapter that you were
looking at).
I implemented this in the streamline code already. To use it, set
"imomentum=1" in the setup file. Note that in this case we are not
solving for the velocity, but for the particle momentum,
p=gamma m v. That means we need to set the initial condition for p in
the data file via gendata.py. In these units, p=R_L (the Larmor
radius), so we would be setting the initial Larmor radius. Then there
is no need to use the parameter alpha!