  Fermionic 87Sr has a nuclear spin of I=9/2, higher than any other element
with similar electronic structure. This large nuclear spin has many
applications in quantum simulation and computation, for which preparation and
detection of the spin state are requirements. For an ultracold 87Sr cloud, we
show two complementary methods to characterize the spin-state mixture: optical
Stern-Gerlach state separation and state-selective absorption imaging. We use
these methods to optimize the preparation of a variety of spin-state mixtures
by optical pumping and to measure an upper bound of the 87Sr spin relaxation
rate.
