KiwiSpec - an advanced spectrograph for high resolution spectroscopy: Prototype design and performance

A new advanced high resolution spectrograph has been developed by Kiwistar Optics of Industrial Research Ltd., New Zealand. The instrument, KiwiSpec R4-100, is bench-mounted, fibre-fed, compact (0.75m by 1.5m footprint), and is well-suited for small to medium-sized telescopes. The instrument makes use of several advanced concepts in high resolution spectrograph design. The basic design follows the classical white pupil concept in an asymmetric implementation and employs an R4 echelle grating illuminated by a 100mm diameter collimated beam for primary dispersion. A volume phase holographic grating (VPH) based grism is used for cross-dispersion. The design also allows for up to four camera and detector channels to allow for extended wavelength coverage at high efficiency. A single channel prototype of the instrument has been built and successfully tested with a 1m telescope. Targets included various spectrophotometric standard stars and several radial velocity standard stars to measure the instrument's light throughput and radial velocity capabilities. The prototype uses a 725 lines/ mm VPH grism, an off-the-shelf camera objective, and a 2kx2k CCD. As such, it covers the wavelength range from 420nm to 660nm and has a resolving power of R approximate to 40, 000. Spectrophotometric and precision radial velocity results from the on-sky testing period will be reported, as well as results of laboratory-based measurements. The optical design of KiwiSpec, and the various multi-channel design options, will be presented elsewhere in these proceedings.