Kast Double Spectrograph User's Manual: Quick Reference

Quick Reference

General Parameters

Scale at Cassegrain focus 3.86 arcsec/mm

Arcsecs/pixel (neglecting anamorphic mag) Red Side: 0.78
Blue Side: 0.43

Monochromatic beam size (both sides) 82.6 mm

Collimator focal length (both sides) 1416 mm

Camera focal length (both sides) 188.7 mm

Approximate Range of Good Performance

Blue lens 3000-7000 Angstroms

Red lens 4000-11000 Angstroms
Approximate Range of Resolution

Blue side 700 - 1700

Red side 500 - 3000

Decker

Predefined Settings

Position Name

0 Home

1 Open

2 Asymmetric Slot 1

3 Asymmetric Slot 2

4 Asymmetric Slot 3

5 Asymmetric Slot 4

6 2 arcsec long

7 15 arcsec long

8 30 arcsec long

9 60 arcsec long

10 Spect

11 Finger

12 2 arcsec rectangular blocker

13 4 arcsec rectangular blocker

14 6 arcsec rectangular blocker

15 8 arcsec rectangular blocker

16 9 arcsec circular blocker

17 6 arcsec circular blocker

18 3 arcsec circular blocker

Maximum decker opening = 145 arcsec

Slit

Predefined Settings

Position Name

0 open

1 0.5 arcsec

2 1.0 arcsec

3 1.5 arcsec

4 2.0 arcsec

5 2.5 arcsec

9 9.0 arcsec

Minimum slit opening = 0.4 arcsec

Maximum slit opening = 145 arcsec

User Filter Wheel Assembly

Position Upper Lower User

0 open open open

1 -- BG14++ --

2 Spinrad NS OG570 --

3 ND 5.0 ND 6.25 --

4 ND 1.25 GG455 --

5 ND 7.5 CuSO4 n/a

6 ND 2.5 GG385 n/a

7 calcite GG495 n/a

Grisms

Grism Grooves/Blaze Straight
Through A/pix Range Nominal
Coverage

1 452/3306 4780 1.41 2890 3150-6200

2 600/4310 4340 1.02 2090 3300-5520 (matches D55)

3 830/3460 3880 0.63 1290 3200-4550 (matches D46)

Collimator Settings

Side Typical Focus Setting Range

blue 15 mm -28 mm to +42 mm

red 0 mm -24 mm to +23 mm

Gratings

Grating Grooves/Blaze A/pix Range Tilt Formula* Useful Range

1 600/5000 2.35 2820 2.21(c)-3906 3800-10000

2 600/7500 2.37 2780 2.22(c)-3970 3800-10000

3** 830/8460 1.70 2040 3.15(c)-4338 3800-10000

4 1200/5000 1.17 1404 4.58(c)-4469 3800-7310

5*** 300/4230 4.59 5508 1.09(c)-3792 3800-11000

6*** 300/7500 4.60 5520 1.09(c)-3781 3800-11000

7 600/3000 2.34 2808 2.21(c)-3733 3000-????

* Where c is the desired central wavelength in angstroms.
** 830/8460 grating in second order yields 0.85 A/pix, range is 1020A, and the second order central wavelength is given by 6.49(c)-5107. The max tilt of 25,500 restricts lambda < 4816A.
*** Note that the 300/7500 is more efficient than the 300/4230 for all lambda greater than ~5400 A. Also, note that 300/7500 in second order can be confused with the 600/7500 grating, but the throughput is very poor and it should not be used in second order.

Polarimeter Module

Position Upper Lower User

0 Home Home Home

1 Open Open In

2 Filter B Out

3 Polaroid V n/a

4 nNone R n/a

5 Empty I n/a

Filter Trays

Position Blue Red

0 Home Home

1 Open Open

2 U GG455

3 wide G GG495

4 empty OG550

5 n/a Spinrad NS

X-Y Stages

Red Side: 37 pixels/mm
Blue Side: 67 pixels/mm
Increasing setting moves to:

Side X (lambda) Y (row)

blue lower higher

red higher lower

Side Spectral Window
(nr nc sr sc) Direct Window
(nr nc sr sc)

blue 325 2048 850 0 325 325 850 850

red 190 1200 140 0 200 200 130 500

Dichroics and Mirror

To get Select

clear Clear

dichroic D46 or D55

mirror Mirror

Support Astronomers (sa@ucolick.org)

Last modified: Mon Oct 3 16:15:09 PDT 2011

User's Guide to the Kast Double Spectrograph

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Quick Reference