  We present here X-ray spectra of the HMXB SMC X-1 obtained in an observation
with the XMM observatory beginning before eclipse and ending near the end of
eclipse. With the Reflection Grating Spectrometers (RGS) on board XMM, we
observe emission lines from hydrogen-like and helium-like ions of nitrogen,
oxygen, neon, magnesium, and silicon. Though the resolution of the RGS is
sufficient to resolve the helium-like n=2->1 emission into three line
components, only one of these components, the intercombination line, is
detected in our data. The lack of flux in the forbidden lines of the
helium-like triplets is explained by pumping by ultraviolet photons from the B0
star and, from this, we set an upper limit on the distance of the emitting ions
from the star. The lack of observable flux in the resonance lines of the
helium-like triplets indicate a lack of enhancement due to resonance line
scattering and, from this, we derive a new observational constraint on the
distribution of the wind in SMC X-1 in velocity and coordinate space. We find
that the solid angle subtended by the volume containing the helium-like ions at
the neutron star multiplied by the velocity dispersion of the helium-like ions
must be less than 4pi steradians km/s. This constraint will be satisfied if the
helium-like ions are located primarily in clumps distributed throughout the
wind or in a thin layer along the surface of the B0 star.
