• Optical Design by Prime Optics (V18)
  1. Full Report (Pkzipped)
  2. Optical specifications for the main spectrograph and Halpha camera: specs V18 (Postscript)
  3. Displacement and tilt tolerances for the main spectrograph and Halpha camera: tols V18 (Postscript)
  4. ZEMAX files describing version 18 main spectrograph and Halpha camera at WHT and TNG: zmx V18 (in one ascii file)
  5. Prescription data files which list the optical elements, their size and weight etc:
     • for main spectrograph (ascii file)
     • for collimator and Halpha camera (ascii file)
  6. A convenient listing of all three optical units with sizes and thicknesses: table V18
  
  
• Suggested design (Prime Optics and RSAA) supplied by Matthew Doolan 5.2.2004:

  I have attached the spot diagrams and the ray trace of the H-Alpha camera. The ray trace starts from the lens group just in front of the beam splitter for ease of viewing. The Zemax file contains the entire system. Configuration 1 is for the WHT and configuration 2 is for the TNG.

  I have also attached a drawing of the focus mechanism as it is currently designed. This design is based around our previous system and understanding of the dewar attachment. I am wondering if this mounting system is satisfactory for you. The drawing should be sufficient to evaluate the system but if you have further questions feel free to quiz me. The drawing represents the configuration which has the focal plane closest to the focus mechanism, the TNG.

  1. FocusMechanism.pdf
     
     
  2. RaytraceConfig1.pdf
  3. SpotDiagramConfig1.pdf
  4. EERConfig1.pdf
     
     
  5. RaytraceConfig2.pdf
  6. SpotDiagramconfig2.pdf
  7. EERConfig2.pdf
     
     
  8. PNS3-18-1-WT-Halpha1-03.SES
  9. PNS3-18-1-WT-Halpha1-03.ZMX

Other information:

Joining optics:

RSAA proposed using oil for coupling of the collimator doublet. This is preferred over grease as bubbles are hard to remove from grease (email John Hart Sep 1999). Damien says that oil and grease are equally OK and that technical staff at AAO could perhaps recommend a suitable type. (email 15/10/99). Keith notes that ICOS used a high viscosity grease to cope with differential thermal expansion in the LDSS optics.

Cementing seems to be an unpopular option. (16/12/99)