MODS Gratings and Prisms

Updated: 2011 Jan 15 by R. Pogge (OSU Astronomy)

Each of the red- and blue-channels of MODS have 4-position grating turrets with a selection of imaging flats and dispersers (gratings and prisms).

The grating turret position may be selected by gratID (preferred) or by position number (deprecated).

MODS1

Blue Grating Turret

Pos	gratID	Description	Resolution (0.6")	Wavelengths
1	Flat	Imaging Flat + Protected Aluminum Nr1	n/a	3100-6000A
2	G400L	400l/mm Blue Grating RGL# MR162-2-7-1	R=1850	3100-6000A
3	P450L	FuSi+Immersed Aluminum Double-Pass Prism Nr1	R=420-140	3500-6000A
4		Position Empty

Red Grating Turret

Pos	gratID	Description	Resolution (0.6")	Wavelengths
1	Flat	Imaging Flat + Protected Silver Nr1	n/a	5000-10000A
2	G670L	250l/mm Red Grating RGL# MR122-5-5-1	R=2300	5000-10000A
3	P700L	TIH6+Immersed Silver Double-Pass Prism Nr1	R=500-200	6000-10000A
4		Position Empty

MODS2

Blue Grating Turret

Pos	gratID	Description	Resolution (0.6")	Wavelengths
1	Flat	Imaging Flat + Protected Aluminum Nr2	n/a	3100-6000A
2	G400L	400l/mm Blue Grating RGL# MRxxx-x-x-x	R=1850	3100-6000A
3	P450L	FuSi+Immersed Aluminum Double-Pass Prism Nr2	R=420-140	3500-6000A
4		Position Empty

Red Grating Turret

Pos	gratID	Description	Resolution (0.6")	Wavelengths
1	Flat	Imaging Flat + Protected Silver Nr2	n/a	5000-10000A
2	G670L	250l/mm Red Grating RGL# MRxxx-x-x-x	R=2300	5000-10000A
3	P700L	TIH6+Immersed Silver Double-Pass Prism Nr2	R=500-200	6000-10000A
4		Position Empty

-- RichardPogge - 16 Jan 2011