  The near-forward cross section for the pp -> pn pi^+ reaction has been
measured at 492 MeV by using the large acceptance ANKE magnetic spectrometer
placed at an internal target position of the storage ring COSY-Juelich. Protons
and pions emitted near zero degrees were detected in coincidence, and those
with theta_pi <= 2 degrees and theta_p <= 2.5degrees were subjected to detailed
analysis. Under these conditions, the excitation energy in the np system was
below 3 MeV over the measured momentum range. This is the region of the np
final-state-interaction peak, which was measured with a resolution of a
fraction of an MeV. The shape of the peak allows one to conclude that the
fraction of final spin-singlet np pairs is below about 10%. By using the
results of scattering theory, this limit is confirmed through a comparison with
the cross section for pp -> d pi^+. The smallness of the singlet contribution
is consistent with trends seen in lower energy data.
