Zgoubi is a raytracing code.
Since 1972 it pushes charged particles through accelerators and beam lines, by stepwise solution of Lorentz force equation - and their spins via Thomas-BMT differential equation.
Zgoubi simulates beam dynamics and polarization in a variety of accelerators (storage ring, synchrotron, cyclotron, betatron, microtron, FFAG, multi-pass ERL, etc) and optical systems (beam lines, magnetic and electrostatic optical components, time-of-flight and mass spectrometers...