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Description

In the reimaging/spectrograph mode, the observer can choose between a series of available longslits or can prepare his/her own multislit mask. There are six aperture positions; one is permanently clear, while the other five are available for various masks. The standard setup (as of 1995 February 20), is given in Table 5. All of the longslits can be removed to allow for more multislit mask locations.

There exist two kinds of slitmask holders: the ``older'', flat-topped version, onto which the masks are attached using tape; and the ``newer'' version with a metal cover that locks on top of the mask itself. There are 5+ of each kind available in one of the COSMIC black pouches, although one or more of each kind appear not to work (and are labelled as BAD).

There are plans to create a series of longslits with various widths using the photographic emulsion process. These photographic slits appear to have excellent uniformity of slitwidth, while the one metal longslit has a substantial variation in the slitwidth. There will also be longslits of various offsets in the focal plane which will allow for the selection of different center wavelengths.

It is recommended that you do not use the metal longslit, as it has collected a great deal of garbage onto the slit opening which results in an uneven width along the slit. We suggested you use one of the film longslits instead.


Table 5
Standard Aperture Mask Setup
Position Aperture
1 clear, unavailable
2 open, available
3 open, available
4 1.5'' photographic longslit, or available
5 2.0'' photographic longslit, or available
6 1.5'' metal longslit (variable width!), or available



next up previous
Next: Mounting a Photographic Slitmask Up: The Aperture Masks Previous: The Aperture Masks
Roy Gal
4/25/1998