The NEID precision radial velocity spectrometer: optical design of the port adapter and ADC

NEID is a new extreme precision Doppler spectrometer for the WIYN telescope. It is fiber fed and employs a classical white pupil Echelle configuration. NEID has a fiber aperture of only 0.92” on sky in high-resolution mode, and its tight radial velocity error budget resulted in very stringent stability requirements for the input illumination of the spectrograph optics. Consequently, the demands on the fiber injection are challenging. In this paper, we describe the layout and optical design of the injection module, including a broadband, high image quality relay and a high-performance atmospheric dispersion corrector (ADC) across the bandwidth of 380 – 930 nm