Optics, General
| Primary Diameter |
3498.85mm (137.75") |
| Primary Focal Ratio |
1.7505 |
| Tertiary Location Above Primary |
475.4mm (18.73") |
| Baffle Diameter |
1446.2mm (56.94") 17.1% |
Primary Mirror
| Blank Diameter |
3511.55mm (138.25") |
| Diameter (to bevels) |
3498.85 (137.75") |
| Edge Thickness |
463.9mm (18.264") |
| Center Hole Diameter |
965.2mm (38") |
| Sagitta |
124.92mm (4.918") |
| Cass Hole Sagitta |
9.4mm (0.370") |
| Glass |
Borosilicate |
| Mirror Weight |
196Kg (4320lbs) |
| Cell Weight |
5854Kg (12,280lbs) |
| CG Location |
468mm (18.43") from vertex |
| Surface Quality |
0.025 waves rms |
| |
0.34 waves P-V |
| |
0.09 arcsec FWHM @ 500nm |
| Surface Roughness |
8 Angstrom (average) |
Secondary Mirror
| Diameter |
1200mm (47.25") |
| Center Thickness |
156mm (6.142") |
| Glass |
Zerodur |
| Weight |
119.5Kg (263lbs) |
| Cell Weight |
110Kg |
| Surface Quality |
0.024 waves rms |
| |
0.26 waves P-V |
| Seconday Roughness |
11.6 Angstroms average |
| |
|
| Secondary Articulation |
|
| Focus Travel |
1.5cm |
| Linear Resolution |
0.125 micron steps |
| Pivot Point Location |
310mm (12.23") above secondary |
| Tilt Resolution |
0.014 arcsec angular image displacement |
| Speed |
1600 steps per second |
| |
0.09 arcsec FWHM @ 500nm |
| Surface Roughness |
8 Angstrom (average) |
Tertiary Mirror
| Ellipse Dimensions |
1101mm x 776mm (43.35" x 30.55") |
| Thickness |
101.6mm (4.00") |
| Weight |
60Kg (132 lbs) |
| Cell Weight |
76Kg (173 lbs) |
| Surface Quality |
0.026 waves rms |
| |
0.428 waves P-V |
| |
0.022 arcseconds FWHM |
| Surface Roughness |
Better than 20 Angstroms |
As Built Optical Prescriptions
| Effective Focal Length |
22004.5 |
| Total Track |
4202.87 |
| Image Space F/# |
6.28906 |
| Exit Pupil Diameter |
1361.08 |
| Exit Pupil Position |
-8559.89 |
| Back Focal Distance |
2706.81 |
| Plate Scale (On Axis) |
9.372 arcsec/mm |
| Distortion |
0.002% |
| |
0.2 degree of axis |
| Magnification |
3.5915 |
| Field of View |
12 arcmin (aproximate) |
| Wavelength Coverage |
Panchromatic |
| Lens Units |
Millimeters |
| Surface Radius |
Thickness |
Glass |
Diameter |
Conic |
| STO -12253.5 |
-4202.869 |
MIRROR |
3500 |
-1.0708 |
| (2) -5332 |
4202.869 |
MIRROR |
1136.592 |
-3.74 |
| (3) Infinity |
-475.4 |
|
536.8658 |
0 |
| (4) Inifinity |
0 |
|
797.9691 |
0 |
| (5) Infinity |
-3182.21 |
MIRROR |
604.2212 |
0 |
| IMA |
0 |
|
15.653 |
0 |
Updated on March 18, 2021, 9:15 am