In my proposed device, the field lines are uniform and the single species ions all orbit identically. They are able to follow their entire cyclotron trajectory,

In my proposed device, the field lines are uniform and the single species ions all orbit identically. They are able to follow their entire cyclotron trajectory, and all these trajectories intersect the same area at the same time. Penning traps are known for their excellent containment characteristics in all directions, but the maximum density of a non-neutral plasma is not usually sufficient for fusion to occur before the Brillouin limit is reached. My device exceeds the Brillouin limit only for short periods of time, but in a way that might be able to oscillate stably.