ASTRO-E/XRS blocking-filter calibration

We describe the transmission calibration of the Astro-E XRS blocking filters. The XRS instrument has five aluminized polymide blocking filters. These filters are located at thermal stages ranging from 200 K to 60 mK. They are each about 1000 angstrom thick. XRS will have high energy resolution which will enable it to see some of the extended fine structure around the oxygen and aluminum edges of these filters. Thus, we are conducting a high spectral resolution calibration of the filters near these energies to resolve out extended fine structure and absorption lines.