Optical Database

JKT-Main optics

Authors: M.F.Blanken

Revision 0.2 04/10/00

Revision History

0.1Firstdraft

Filename: \\Ormnt1\Group_Area\Optics\Master_Documents\JKTMain.doc

Owner: M.F.Blanken

Content:

Optical specifications    *

Mechanical specifications          *

Cleaning           *

Measurements  *

Aligning            *

Aluminising       *

Reference:        *

 

Main website of the JKT

http://www.ing.iac.es/Astronomy/telescopes/jkt/index.html

 

Optical specifications

Element

Shape

Working Diameter (mm)

Asphericity

Focal length (mm)

Separation from primary (mm)

Primary

Concave Parabolic

1000

-1

4596

 

F/8 Secondary

Sphere

477

0

4381

2738

Secondary f/15

Convex Hyperbolic

307

-3.545

1811

3342

Afocal doublet

sphere

326

 

Afocal

914

Finder (doublet)

sphere

200

 

 

 

 

 

Focal Station

Harmer-Wynne

Cassegrain

Finder

Focal length (mm)

8060

15000

3250

Focalratio

F/8.06

F/15

F/16.25

Field diameter

(arcmin)

(no vignetting)

(50%vignetting)

 

 

90

93

 

 

34

50

 

 

10,30,90 (2)

Scale (arcsec/mm)

25.6

13.8

63.5

Diameter of central obstruction (mm)

618

406

63.5

Focus/mirror shift (1)

4

11.7

 
  1. Movement of focus position for unit movement of secondary mirror
  2. Depends on eyepiece used

Mechanical specifications

Element

Shape

Total Diameter (mm)

Expn. Coef. (1/K)

Material

Primary

Concave Parabolic

1000

0.1±0.1x10-6

Cervit

F/8 Secondary

Convex Sphere

477

-0.7x10-6

Zerodur

F/15 Secondary

Convex Hyperbolic

307

-0.7x10-6

Zerodur

Afocal doublet

Sphere (doublet)

326

 

UBK7

Finder

Sphere (doublet)

200

 

 

 

Cleaning

Dates of snowcleaning

Document of the snowcleaning

Measurements of snowcleaning before and after

 

Measurements

 

Aligning

Aligning

Documents of the aligning procedures

 

Aluminising

Dates of last aluminising.

Measurements before and after the aluminising.

 

Reference:

D.Carter, U.Sharan & R.E.S.Clegg