La Silla - Science Operation Department

NTT technical info

Technical characteristics

	New Technology Telescope
Location
Location	70° 43'54.272" W -29° 15'18.440" S
Altitude	2375 m.
Optical Design	Richey-Chretien
Main Mirror	Schott Zerodur
Diameter	3.58m, thin meniscus (24cm),
Active Optics	75 actuators, 3 fixed points, 24 lateral actuators
Focal Ratio	f/2.2
Secondary Mirror	Schott Zerodur
Diameter	0.875m
Central Obstruction	1.16m
Tertiary Mirror	Schott Zerodur
Major x minor axis	0.840 x 0.600m
Nasmyth foci
Field of view	30arcmin, 336.6mm
Focal Ratio	f/11
Plate scale	5.35905 arcsec/mm
Max.possible load on the Nasmyth adapter	2000Kg at 270mm from the fixation flange of the instrument
Distance adapter-focal plane of the telescope	500mm from the fixation flange
Lateral displacement at the focal plane for max. load on adapter	6.2microns
Max. allowable tilt of the hub	3" for a load of 800N at 400mm from the fixation flange
Image Quality	80% energy in 0.15" in all telescope position

Surfaces	10
Stop	5
System Aperture	Entrance Pupil Diameter = 3500
Glass Catalogs	schott MISC
Ray Aiming	Off
Apodization	Uniform, factor = 8.00000E+000
Effective Focal Length	38501.74 (in air at system temperature and pressure)
Effective Focal Length	38501.74 (in image space)
Back Focal Length	21267.2
Total Track	6500
Image Space F/#	11.0005
Paraxial Working F/#	11.0005
Working F/#	11.00618
Image Space NA	0.04540561
Object Space NA	1.749999e-007
Stop Radius	1750
Paraxial Image Height	0
Paraxial Magnification	0
Entrance Pupil Diameter	3500
Entrance Pupil Position	6500
Exit Pupil Diameter	949.3438
Exit Pupil Position (before image plane)	10443.25
M1-M2 distance	5933.3
M1-M3 distance	1200
M3-focus distance	4100.6
Radius of curvature in the image plane	1898
Field Type	Angle in degrees
Maximum Field	0
Primary Wave	0.55
Lens Units	Millimeters
Angular Magnification	0