Cyclotron elements require end position to have larger radius than start position
Found with @nesteruk_k:
In the current implementation it is assumed that the Probe (x,y) end position has a larger radius than the (x,y) starting position.
If not, almost no particles are recorded. This is not documented and without warning not very user-friendly, therefore labelling this a bug. For 1.6 perhaps a documentation update would be enough.
EDIT (23 April): (C)Collimator, Septum, Stripper make the same assumption.