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Gratings and Optical Elements

GHRS Instrument Handbook


Design and Construction of the GHRS

Table 6.1: Properties of GHRS Gratings

Note that the "CD" gratings are cross-dispersers for the echelles. CD-A has a focal length of 1460 mm and CD-B has a focal length of 1340 mm. Note also that the "M" gratings are holographic and that the blaze angle quoted formally is that which correctly predicts the center of the wavelength region the grating is optimized for. G140L is a ruled grating. "Ech-A" and "Ech-B" refer to two modes of operation that use the same echelle grating but different cross-dispersers and detectors.

Table 6.2: Properties of Other GHRS Optical Components

Figure 6.5: Schematic diagram of GHRS acquisition optics. The "main acquisition mirror" is N2.

Table 6.1: - Properties of GHRS Gratings
Table 6.2: - Properties of Other GHRS Optical Components
Figure 6.5: - Schematic diagram of GHRS acquisition optics. The "main acquisition mirror" is N2.