  We present results from our 830 ksec observation of the globular cluster 47
Tucanae with the Chandra X-ray Observatory's High Resolution Camera-S. We limit
our analysis here to the 19 previously known, localized millisecond pulsars
(MSPs) in the cluster. This work more than doubles the sample of X-ray-detected
MSPs observed with sensitivity to rotational variability; it is also the first
survey of a large group of radio-discovered MSPs for which no previous X-ray
pulsations have been detected and is therefore an unbiased survey of the X-ray
properties of radio-discovered MSPs. We find that only 47 Tuc D, O and R show
significant pulsations at the >~ 4-sigma level, but there is statistical
evidence for rotational variability in five additional MSPs. Furthermore, we
constrain the pulsed magnetospheric emission of 7 more MSPs using Monte Carlo
simulations. The result is that the majority of the 47 Tuc MSPs are
characterized by low pulsed fractions, <~ 50%. In cases where larger pulsed
fractions are measured the folded pulse profiles show relatively large duty
cycles. When considered with previous spectroscopic studies, this suggests that
the X-ray emission arises from the neutron star's heated polar caps, and in
some cases, from intra-binary shocks, but generally not directly from the
star's magnetosphere. We discuss the impact of these results on our
understanding of high energy emission from MSPs.
