%\subsection{Nucleon Nucleon elastic collisions \editor{Johannes Peter}}
Angular distributions for elastic scattering of nucleons are taken as closely as
possible from experimental data, i.e. from the result of phase-shift analysis. 
They are derived from differential cross sections obtained from the SAID 
database, R. Arndt, 1998. 

Final states are derived by sampling from tables 
of the cumulative distribution function of the centre-of-mass scattering
angle, tabulated for a discrete set of lab kinetic energies from
10 MeV to 1200 MeV.  The CDF's are tabulated at 1 degree intervals and
sampling is done using bi-linear interpolation in energy and
CDF values. Coulomb effects are taken into consideration for pp scattering.