CRYSTALLINE ION-BEAMS

Ions confined and cooled in traps or storage rings can arrange themselves in crystal-like ordered structures when the kinetic energy in their thermal motion is reduced sufficiently below the potential energy as a result of their mutual Coulomb repulsion. For high-velocity ions in storage rings, this crystallization holds much promise for the production of beams of unprecedented brilliance, which are expected to overcome several limitations of present-day gaseous beams. We review the theory of crystalline ion beams and discuss the present experimental situation. Very recent developments and achievements, both in theory and experiment, are described, with an eye toward obtaining crystalline beams in the near future.