  We present a novel type of longitudinal Zeeman slower. The magnetic field
profile is generated by a 3D array of permanent spherical magnets, which are
self-assembled into a stable structure. The simplicity and stability of the
design make it quick to assemble and inexpensive. In addition, as with other
permanent magnet slowers, no electrical current or water cooling is required.
We describe the theory, assembly, and testing of this new design.
