  Collapsing magnetic traps (CMTs) have been suggested as one possible
mechanism responsible for the acceleration of high-energy particles during
solar flares. An important question regarding the CMT acceleration mechanism is
which particle orbits escape and which are trapped during the time evolution of
a CMT. While some models predict the escape of the majority of particle orbits,
other more sophisticated CMT models show that, in particular, the
highest-energy particles remain trapped at all times. The exact prediction is
not straightforward because both the loss cone angle and the particle orbit
pitch angle evolve in time in a CMT. Our aim is to gain a better understanding
of the conditions leading to either particle orbit escape or trapping in CMTs.
