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In
this thesis I describe simulations of cold-atom sources, designed to be
included in our experiments in the AtomChip lab. These experiments are
conducted in vacuum conditions of 10^-11 to 10^-12 mbar. Such a high
level of vacuum sets strict limitations for the process of loading
atoms into the atomic traps necessary for successful realizations of
the experiment. Developing a cold-atom source and successfully
implementing it in our experiments will enable faster loading of the
trap while avoiding a damaging increase of pressure in the vacuum
chamber. This is essential for increasing our data collection rate that
is severely hampered by our current restrictions to one experimental
cycle per minute.
Following brief introductions to prepare the background for our models
of simulating atomic motion in vacuum systems, I begin by applying a
commonly used simulation for motion in a magneto-optical trap. I then
develop a new method (called the "photon-recoil" model) for a
stochastic treatment of the light-matter interaction, which produces a
more accurate description for the velocity- and position-dependent
forces acting on the atoms in the trap. I use my newly developed
simulation for evaluating the force acting on an atom in an actual
design of a cold-atom source that can fit the requirements of our
experiments and compare it to results from simulations based on methods
from the literature. I conclude this work by presenting a practical
outline for a two-stage differential pumping scheme, which is essential
for maintaining the low pressure requirements of the existing
experiment, while still shortening the loading time.
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