  We report time-of-flight neutron scattering measurements of the magnetic
spectrum of Tb3+ in Tb2Ti2O7. The data, which extend up to 120 meV and have
calibrated intensity, enable us to consolidate and extend previous studies of
the single-ion crystal field spectrum. We successfully refine a model for the
crystal field potential in Tb2Ti2O7 without relying on data from other rare
earth titanate pyrochlores, and we confirm that the ground state is a
non-Kramers doublet with predominantly |+/-4> components. We compare the model
critically with earlier models.
