Hyperbolic and Cylindrical Penning Traps

The oldest Penning trap geometry in use is the hyperbolic shape, which provides good confinement properties by design, however was difficult to machine to high precisions at the time of its introduction, and offers limited access for particles and laser beams. Thus, cylindrical designs were brought forward, including more open structures with open endcaps. Here, we briefly review the hyperbolic and the most important forms of cylindrical Penning traps.