  An approach for measuring linear X-ray polarization over a broad-band using
conventional spectroscopic optics is described. A set of multilayer-coated
flats reflect the dispersed X-rays to the instrument detectors. The intensity
variation as a function of energy and position angle is measured to determine
three Stokes parameters: I, Q, and U. By laterally grading the multilayer
optics and matching the dispersion of the gratings, one may take advantage of
high multilayer reflectivities and achieve modulation factors over 80% over the
entire 0.2 to 0.8 keV band. A sample design is shown that could be used with a
small orbiting mission.

Astrophysics