European Southern Observatory New Technology Telescope

General :
Observations :
Operations :

Grating Setup

To install a grating :

• Press EMMI emergency stop button at the center of EMMI cover.
• Unscrew the four knobs on the front face of the grating housing and remove the circular protection cover.
• Install very carefully the 2 protection covers in front of the gratings :

check that they are clean : use CO2 if not.
• Unscrew the large knob in the middle of the grating suport..
• Pull the grating a few millimeters and rotate it to horizontal position.
• Remove the grating unit and store it in cupboard #1.
• Verify that the mechanical interface of the new grating is clean.
• Enter the grating unit horizontally around the axis: a few millimeters before the end, rotate it until finding the driving pin.
• Screw in the fixation knob.
• Remove the two protection covers of the grating unit.
• Put back the housing circular cover and screw the four knobs.
• Check that Echelle mask is not in the REMD path.
• Release the EMMI emergency stop button at the center of EMMI cover.
• On EMMI configuration panel, click not mounted, then set Echelle mask.
• Update EMMI configuration panel, choosing grating name and clicking enter grating.
• Load REMD_spec_tec_CenterGrat or BLMD_spec_tec_CenterGrat templates in BOB
  and edit the grating name.
  
• Start REMD_spec_tec_CenterGrat or BLMD_spec_tec_CenterGrat templates to Center order 0.
  REMD_spec_tec_GratingAlign or BLMD_spec_tec_GratingAlign which measure misalignment.are included in the same obd
  and must be run afterwards.
  
• Check that EMMI configuration panel is modified accordingly.
• Click Backup under File submenu.
• Load REMD_all_tec_SetFoc or BLMD_spec_tec_SetFoc and edit grating name.
• Run REMD_all_tec_SetFoc or BLMD_spec_tec_SetFoc to tune focus vs/ temperature formula.
  • if the focus curve is a nice parabola and the new focus parameter is not too different
    from the previous one ( less than 200 encoder units ) you may answer YES to the popup question.
    
• Load REMD_all_tec_CheckFoc in bob and edit grating name and wavelength as from setup request.
• Run REMD_all_tec_CheckFoc to measure defocussing at red observing wavelengths.
  ( BLMD_all_tec_CheckFoc is not necessary as BLMD focus doesn't vary significantly with wavelength ).
  if the focus curve is NOT a nice parabola
  • cd ~ins
  • ls -rlt focOffset*
  • use the absolute value in the last file corresponding to the today configuration which is slower than 15.
    
  
  
• For BLMD and REMD, test flexures everytime.
• Report the best focus temperature for each observing wavelength

in the calibration log book.

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