Polarization of Three Vacuum-Ultraviolet Monochromators Measured with a Biotite Polarizer*

The effective transmittance and the degree of polarization of two types of reflection polarizers, one a pyramidal type and the other a parallel type, are compared. A pyramidal polarizer was used to measure the polarization of three different monochromators in the region 1000–2000 Å. The exit beam from two near-normal-incidence monochromators, a McPherson 225 and a McPherson 218, was not significantly polarized, while that from a Jarrell–Ash Seya–Namioka monochromator was about 35% polarized at 1000 Å.