User's Guide to the Hamilton Spectrograph


Table of Contents


Introduction
Quick Reference
Hardware
CCD Characteristics
Apertures
Grating Tilt & Dewar Height
Filter Wheel & Shutter
Calibration Sources
Photon Integrator
Image Rotator
Iodine Cell & Slit Room Controller
Guide Camera & Filter Wheel
Software
Data Taking System
Hamilton Motor Controller
Showmidpoint
Eventsounds
Hamilton Focus
More Info:
Spectral Format
Navigating the Spectrum
Table of Orders
Setup Procedures
Checklists
Observing Hints
Throughput

Data Archive
Mt. Hamilton Homepage

Grating Tilt and Dewar Height

The Grating Tilt and Dewar Height stages are used to position the spectrum on the detector. Both these stages are controlled from the spectrograph motor control interface hammotor_gui (see Figure 1 for the GUI interface). Both stages use motor steps as the units. The scale factors for moving the spectrum on the detector are as follows:
Grating Tilt 1.15 steps/pixel (Dewars 6 and 8)
0.92 steps/pixel (Dewar 4)
Positive grating tilt settings will move the spectrum to the right, revealing bluer wavelength.
Dewar Height 8.97 steps/pixel (Dewars 6 and 8)
7.18 steps/pixel (Dewar 4)
Positive dewar height settings will move the spectrum up, revealing bluer orders.

See Navigating the Spectrum for more information on identifying wavelengths and positioning the spectrum on the detector.


Figure 1: Grating Tilt and Dewar Height


Figure 2: Translating the spectrum on the detector.


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Last modified: Tue Feb 15 14:14:15 PST 2011