  We study the ability of three-frequency, arcminute-resolution microwave
measurements to detect galaxy clusters via their Sunyaev-Zel'dovich (SZ)
distortion of the microwave background. For this purpose, we have constructed
large-area simulations of the microwave sky, and we have made them publicly
available to further investigations into optimal data reduction techniques for
upcoming SZ cluster surveys. In these sky simulations, galaxy clusters are
modeled using N-body simulated dark matter halos plus a gas prescription for
the intracluster medium that allows the small scale cluster physics such as
star formation and feedback to be realistically incorporated. We also model the
primary microwave background, radio and infrared point sources, galactic dust
emission, and the SZ flux including kinetic and relativistic contributions. We
make use of these simulations to study the cluster scaling relation between
integrated SZ flux and cluster mass and find our clusters fit a power-law well,
with a power-law index that is steeper than that for self-similar cluster
models. Some evolution of the power-law index and normalization with redshift
is also observed. These simulations are also used to study cluster detection
for the Atacama Cosmology Telescope (ACT). Using a multi-frequency Wiener
filter to separate clusters from other microwave components, we find that ACT
alone can recover a cluster sample that is ~90% complete above 3*10^{14} M_sun
and ~85% pure.
