TRAGOS
TRAnsmission Grating Optical Spectrograph
Developed for use in the Open University SXR208 residential astronomy course at the Observatori Astronomic de Mallorca (OAM), Costitx, Spain
TRAGOS design PDF
Tests performed on Feb. 18, 2004
Test setup of optical components: Images obtained during alignment of optical components:
Top : collimator + transmission grating + prism wedge
Bottom: collimator + transmission grating
Note: here one sees the collimated beam in 0th and higher orders. One also can see how the spectrum is shifted onto the optical axis after inserting the prism wedge and how nearly all the light is dispersed into the 1st order on one side.
Same as above but with the higher orders enhanced
Above: two views of the aligned optical components : collimator lense, transmission grating, prism wedge, objective lens
Above and Left: combination of the optical component and an ST-5 camera for first tests. With the ST-5 a wavelength range of 2000A is covered
Results from Feb 18, Measurements
Using an SBIG ST-5 (320 pix) in dispersion direction we get a wavelength range coverage from 4000 A - 6700 A with a dispersion of 8.5A/pix. For the Hg line at 5460A we find a FWHM = 2.7653 pixels = 23.39 Angstroms from which we get a resolution of R ~ 233 using a 50micron pinhole. Using a 25micron slit the resolution should increase to R ~ 350.
Extracted raw spectra (Feb 19, 2004):
Neon (Ne)
Mercury (Hg)
Argon (Ar)
Status of mechanical pieces Feb. 20, 2004
All mechanical parts are machined at the Teaching Workshop (Ausbildungswerkstatt) at MPE
An overview and detailed images of the parts machined up-to date
Last modified by Vadim Burwitz
20/02/2004 16:45:12 CET