Decker

The dimensions of the decker plate which defines the slit length are given in Table 1. With the decker in the open position, the slit illuminates $\sim 360$ rows on the Loral 1K CCD. There is some vignetting at the ends of the slit in the open position.

 

 

Table 1: Decker Plate Dimensions for the 1.5-Meter Cassegrain Spectrograph

Decker	Stellar Window
Number	At Slit
	(mm)	(arcseconds)
1	0.90	16
2	1.55	28
3	2.20	40
4	3.00	54
5	3.75	68
6	4.50	81
7	6.00	109
8	8.90	161
9	11.90	215
10	17.75	321
open	25.40	460