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The HDS System

HDS is located at one of the Nasmyth foci (the so-called Optical Nasmyth) of the Subaru Telescope. Image rotators, calibration lamps (CAL), image slicer (IS), and an atmospheric dispersion compensator (ADC) are located ahead of the slit. In this subsection the HDS system is described following the order along the optical path of the beam. The important parameters of the optical elements and the detector are given in Table [*]. The pre-slit unit elements and functions functions are explained in Section [*].


Table 1: System of HDS

  Characteristics

Slit
length 1000~30000 μm (2-60arcsec)
  width 10~2000 μm (0.02-4arcsec)
Filter 1 ND1, ND2, SQ, OG530, KV408
  2 SC46, SC42, GG495, KV389, KV370
shutter   shortest exposure is 1 sec.
collimator red off-axis parabola
  blue off-axis parabola
echelle   31.6 grooves/mm, blaze angle 71.25 degrees
cross disperser red 250 grooves/mm, blaze angle 5.00 degrees
  blue 400 grooves/mm, blaze angle 4.76 degrees
  mirror  
camera system   focal length 770mm
detector   EEV CCD 4100 pix × 2048 pix × 2, 13.5 μm/pix

   

Figure 1: Optical layout of HDS
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next up previous contents
Next: Performance of HDS Up: Instrument Characteristics Previous: Characteristics of the Echelle   Contents

aoki, helminiak, tajitsu 2014-02-11