The ability to trap matter is of great importance in experimental physics since it allows isolation and measurement of intrinsic properties of the trapped matter. We present a study of a three dimensional (3D) trap for a diamagnetic rod in a pair of
diametric cylindrical magnets. This system yields a fascinating 1D camelback potential along the longitudinal axis which is one of the elementary model potentials of interest in physics. This potential can be tailored by controlling the magnet length/radius aspect ratio. We developed theoretical models and verify them with experiments using graphite rods. We show that, in general, a camelback field or potential profile exists in between a pair of parallel linear dipole distribution. By exploiting this potential, we demonstrate a unique and simple technique to determine the magnetic susceptibility of the rod. This system could be further utilized as a platform for custom-designed 1D potential, a highly sensitive force-distance transducer or a trap for semiconductor nanowires.
