The slit mask handler (below) will install several different types of masks, including long slits, 5 arc-min mutlislit masks (flat), and 30 arc-min dia. multi-slit masks (spherical shells). Long slits of various widths will be available on one of the long slit frames, and four 5 arc-min multi-slit masks will be loaded on each of the frames dedicated to them.
The slit mask material is expected to be 6061 aluminum of a currently unspecified thickness. A minimum of 500 mask blanks will be provided. It is anticipated that the mask blanks will be stamped or pressed into the spherical shape, and then mounted in frames. The frames will carry kinematic features which engage on the machine tool which cuts the slits into the masks. A minimum of 10 prefabricated frames will be provided. The same kinematic features will locate the mask frames at the telescope focal surface. Masks will be cut at ambient temperature to minimize thermal scale changes. The time required to machine a set of four masks should not exceed 8 hours.