GNIRS image slicers at GEMINI: Design & manufacturing
Abstract
This contribution presents two image slicers (low resolution (LR) and high resolution (HR)) being built at Durham University for the Gemini Near-Infrared Spectrograph (GNIRS) at the 8m Gemini North telescope. The original LR IFU was destroyed during a thermal runaway in 2007. The same design is currently being re-manufactured with enhanced diamond turning techniques and materials, improving the surface roughness on the optical surfaces to sub 4 nm RMS. For the HR IFU a new image slicer has been designed within the same envelope defined by the LR IFU (0.1 x 0.2 x 0.1 m3) and it will also be manufactured at Durham University. The LR IFU was designed to sample the 20th percentile seeing obtained with just tip-tilt correction. The field of view is 15 arscec 2 (3.15" x 4.80") covered by 21 slices with a spatial sampling of 0.15 x 0.15 arcsec2. The HR IFU will be optimised for fully adaptively corrected images over a field of view of 2.25 arcsec2 (1.80" x 1.25") covered by 25 slices giving a spatial sampling of 0.05 x 0.05 arscec2. Both designs are diffraction limited at infrared wavelengths (1 - 5.4µm).
- Publication:
-
XIV.0 Scientific Meeting (virtual) of the Spanish Astronomical Society
- Pub Date:
- July 2020
- Bibcode:
- 2020sea..confE.218C