Resultssp.gif (42 bytes)Gallery

Eucalyptus

With the aim of testing the use of 50mm core fibers for the SOAR IFU spectrograph, and the training of the team in some techniques necessary to the construction of the SOAR instrument, we planned and built a prototype spectrograph that is currently operating on the 1.6m Observatório do Pico dos Dias telescope.

This prototype was built by a team of the LNA and IAG-USP, based on the projects of the SPIRAL spectrograph, from the Anglo-Australian Observatory. The name  Eucalyptus was chosen because it is a native Australian tree that adapted very well in Brazil.

The first scientific data obtained in february / 2001, confirm the possibility of using 50mm fibers, both from the point of view of efficiency as of stability to torsions and tensions caused by the telescope movement.

Eucalyptus Main Characteristics

I F U

Fibers Polymicro blue fibers - 50 mm core
Number of fibers 512
Microlenses Limo cylindrical array 16 x 32 (1 mm pitch)
IFU Focal ratio input - output f /10 - f / 5.5
Spatial coverage 0.9" per microlens ( 15"x 30" )

Spectrograph

Bench mounted, quasi Littrow  
Spectral Resolution   4 000 ( 600 grooves / mm grating)
  12 000 (1800 grooves / mm grating)
Wavelength coverage 400 - 900 nm 
  40 nm in one shot ( CCD 106, 600 grooves/mm gr.)
Calibration Unit He - Ne - Ar lamps

Efficiency

Sky   ~ 80 %
Telescope       78 %
Foreoptics       90 % 
IFU       53 %
Spectrograph       56 % (without coating)
CCD       60 % (# 106 - at 650nm)
Grating    ~ 60 % (at 650nm)
Total    6 %  (expected 11 % with coating + new CCD)