WHT-Main
optics
Authors:
M.F.Blanken
Revision
0.2 04/10/00
Revision History
Filename: \\Ormnt1\Group_Area\Optics\Master_Documents\WHTMain.doc
Owner: M.F.Blanken
Optical specifications *
Mechanical specifications *
Cleaning *
Measurements *
Aligning *
Aluminising *
Reference: *
http://www.ing.iac.es/~crb/wht/index.html
|
Shape |
Working Diameter (mm) |
Asphericity |
Focal length (mm) |
Separation from primary (mm) |
Diameter of central shadow (mm) |
|
|
Primary |
Concave parabolic |
4180 |
-1 |
10439.6 |
|
1220 |
|
Secondary f/11 |
Convex hyperbolic |
1001 |
-2.5329 |
-3115.7 |
8035 |
|
|
Nasmyth |
Flat |
63x432 |
0 |
|
1750 |
|
|
Focal Station |
Prime (without corrector) |
Prime (with corrector) |
Cassegrain |
Nasmyth (without image derotator) |
Nasmyth (with image derotator) |
Nasmyth (with infrared derotator) |
|
Focal length (mm) |
10440 |
11739 |
45738 |
45738 |
46419 |
45738 |
|
Focal ratio |
F/2.498 |
F/2.81 |
F/10.94 |
F/10.94 |
F/11.11 |
F/10.94 |
|
Field diameter (arcmin) (no vignetting) (50%vignetting) |
|
40 60 |
15 19 |
7 23 |
2.5 5 |
2.9 |
|
Scale (arcsec/mm) |
19.76 |
17.55 |
4.51 |
4.51 |
4.44 |
4.51 |
|
Diameter of central obstruction (1) (mm) |
19.76 |
17.55 |
4.51 |
4.51 |
4.44 |
4.51 |
|
Focus/mirror shift (2) |
|
|
20 |
20 |
21 |
20 |
1) Theoretical obscuration (baffles + vanes) = 9.083%
2) Movement of focusposition for unit movement of secondary mirror
|
Element |
Shape |
Total Diameter (mm) |
Expn. Coef. (1/K) |
Material |
Axialthickness (mm) |
|
Primary |
Concave parabolic |
4220 |
0.1±0.1x10-6 |
Cervit |
452 |
|
Secondary |
Convex hyperboloid |
1001 |
-0.7x10-6 |
Zerodur |
168 |
|
Nasmyth |
Flat |
616x432 |
0.1±0.1x10-6 |
Cervit |
51 |
Dates of snowcleaning
Document of the snowcleaning
Measurements of snowcleaning before and after
Documents of the aligning procedures
Dates of last aluminising.
Measurements before and after the aluminising.
Richard Bingham (RGO) Sept.1984 RGO/LaPalma Technicalnote No.9
D.Carter, U.Sharan & R.E.S.Clegg