User's Guide to the Kast Double Spectrograph


Table of Contents


Introduction
Quick Reference
Hardware Overview
Common Path
Blue Side
Red Side
Detector Characteristics
Software
Kast Controller
Data Taking System
Position Angle
Arc and Flat-field Lamps
Diagonal Mirror
Kast Focus
Eventsounds
Telescope Offset
Setup and Observing Hints
Setup Procedures
Observing Hints
Calibration Lamp Spectra
Exposure Time Calculator

Mt. Hamilton Homepage

Quick Reference

General Parameters | Decker | Slit | User Filter Wheel Assembly | Grisms | Collimator Settings | Gratings | Polarimeter Module | Filter Trays | X-Y Stages | Spectral and Direct Windows | Dichroics and Mirror


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
PositionName
0Home
1Open
2Asymmetric Slot 1
3Asymmetric Slot 2
4Asymmetric Slot 3
5Asymmetric Slot 4
62 arcsec long
715 arcsec long
830 arcsec long
960 arcsec long
10Spect
11Finger
122 arcsec rectangular blocker
134 arcsec rectangular blocker
146 arcsec rectangular blocker
158 arcsec rectangular blocker
169 arcsec circular blocker
176 arcsec circular blocker
183 arcsec circular blocker
Maximum decker opening = 145 arcsec
Slit
Predefined Settings
PositionName
0open
10.5 arcsec
21.0 arcsec
31.5 arcsec
42.0 arcsec
52.5 arcsec
99.0 arcsec
Minimum slit opening = 0.4 arcsec
Maximum slit opening = 145 arcsec
User Filter Wheel Assembly
PositionUpper LowerUser
0openopen open
1--BG14++ --
2Spinrad NS OG570--
3ND 5.0 ND 6.25--
4ND 1.25 GG455--
5ND 7.5 CuSO4n/a
6ND 2.5 GG385n/a
7calcite GG495n/a
Grisms
GrismGrooves/Blaze Straight
Through
A/pix RangeNominal
Coverage
1452/3306 47801.41 28903150-6200
2600/4310 43401.02 20903300-5520 (matches D55)
3830/3460 38800.63 12903200-4550 (matches D46)
Collimator Settings
SideTypical Focus Setting Range
blue15 mm -28 mm to +42 mm
red0 mm -24 mm to +23 mm
Gratings
GratingGrooves/Blaze A/pixRange Tilt Formula*Useful Range
1600/5000 2.3628302.22(c)-4283 3800-10000
2600/7500 2.3528202.22(c)-4231 3800-10000
3**830/8460 1.7020403.15(c)-4338 3800-10000
41200/5000 1.1714044.58(c)-4469 3800-7310
5***300/4230 4.5955081.09(c)-3792 3800-11000
6***300/7500 4.6055201.09(c)-3781 3800-11000
7600/3000 2.3428082.21(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
PositionUpperLowerUser
0Home HomeHome
1Open OpenIn
2Filter BOut
3Polaroid Vn/a
4nNone Rn/a
5Empty In/a
Filter Trays
PositionBlue Red
0Home Home
1Open Open
2U GG455
3wide G GG495
4empty OG550
5n/a Spinrad NS

X-Y Stages
Red Side: 37 pixels/mm
Blue Side: 67 pixels/mm

Increasing setting moves to:

SideX (lambda) Y (row)
bluelower higher
redhigher lower

SideSpectral 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 getSelect
clearClear
dichroicD46 or D55
mirrorMirror


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