Experiments with Supersonic Beams as a Source of Cold Atoms

even trap Rydberg atoms [18–20].
Instead of using external optical or electric fields, external magnetic fields can
be applied to the control of the atoms or molecules in the beam. Since magnetism is
nearly universal for atoms in the ground state or a low-lying metastable state, this
a very general approach to controlling atomic motion. Several groups have pursued
this method, and this dissertation presents one approach to using magnetic fields
to control atoms and molecules in supersonic beams. A similar approach has been
pursued independently and in parallel by the group of F. Merkt [21–26].
1.3 Dissertation Outline
Chapter 2 introduces the physics of the supersonic beam. The thermodynamic
properties of a one dimensional adiabatic expansion are derived, and the properties
and advantages of the beam are discussed. The Even-Lavie nozzle, which is the device
used to produce supersonic beams in these experiments, is introduced.
Chapter 3 of this dissertation discusses the Atomic Paddle experiment. In
this experiment, a supersonic beam of helium is slowed by specular reflection from
a moving crystal. While ground state helium is very difficult to control due to its
low polarizability and lack of a magnetic moment, it is known to reflect well from
atomically flat single crystal surfaces. By mounting an externally prepared crystal on
the tip of a spinning rotor that is used to move the crystal along the beam propagation
direction, the velocity of the reflected beam is reduced. Beam temperatures are shown
to be conserved by this process. The experimental apparatus, vacuum chambers, and
crystal preparation and characterization processes are described. The data presented
demonstrates experimental control of the velocity of a helium beam.
Chapter 4 discusses the Atomic Coilgun experiment. Supersonic beams of
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