Particle orbits and drift surfaces in a heliac

Drift orbit topologies in the H-1NF heliac are described using guiding centre calculations and by the approximate second adiabatic invariant. Results are presented that are representative of the orbit topologies across the magnetic configuration space of the machine and in the presence of radial electric fields. The trapped particle population can be divided into a number of different subclasses using a scheme based on the number of maxima in parallel kinetic energy between bounce points.