The DESI wide field corrector optics

Abstract

The Dark Energy Spectroscopic instrument (DESI) is a 5000 fiber multi-object spectrometer system under development for installation on the National Optical Astronomy Observatory (NOAO) Kitt Peak 4m telescope (the Mayall telescope). DESI is designed to perform a 14,000° (square) galaxy and Quasi-Stellar Object (QSO) redshift survey to improve estimates of the dark energy equation of state. The survey design imposes numerous constraints on a prime focus corrector design, including field of view, geometrical blur, stability, fiber injection efficiency, zenith angle, mass and cost. The DESI baseline wide-field optical design described herein provides a 3.2° diameter field of view with six 0.8- 1.14m diameter lenses and an integral atmospheric dispersion compensator.