Optical parameters obtained by echelle simulator

The optical parameters of the echelle spectrograph are adjusted by comparing a real spectral format with a simulated one. Table 3 shows the several parameters.

Table 3: Optical parameters of the IRCS echelle spectrograph

Telescope
Focal length ($f_{tel}$; mm)	100040
Aperture ($D_{tel}$; mm)	8082
Plate Scale (arcsec mm$^{-1}$)	2.062
Collimator
Focal length ($f_{col}$; mm)	300.00	[320.248]
Aperture ($D_{col}$; mm)	25.882
Camera
Focal length ($f_{cam}$; mm)	318.0	[315.386]
Aperture ($D_{cam}$; mm)	34.327
Detector
Type	Raytheon InSb Array
Multiplexer	Aladdin II
Pixel size (mm pix$^{-1}$)	0.027
Echelle grating
Groove spacing ($\sigma_e$; mm)	1.0/31.6
Groove Angle ($\theta_Be$; degree)	63.5	[63.52]
Grating operating angle( $(\alpha - \beta)_{e0}$; degree)	8.0
Cross-Disperser
Groove spacing ($\sigma_c$; mm)	1.0 / 42.5	[1.0/42.35]
Groove Angle ($\theta_Bc$; degree)	8.016
Grating operating angle( $(\alpha - \beta)_{c0}$; degree)	31.34498

* The values in [ ] are original optical design values of IRCS (Warren, 1996).