LLiST: a new-star tracker camera for tip-tilt correction at IOTA

Abstract

The tip-tilt correction system at the Infrared Optical Telescope Array (IOTA) has been upgraded with a new star tracker camera. The camera features a backside-illuminated CCD chip offering doubled overall quantum efficiency and a four times higher system gain compared to the previous system. Tests carried out to characterize the new system showed a higher system gain with a lower read-out noise electron level. Shorter read-out cycle times now allow to compensate tip-tilt fluctuations so that their error imposed on visibility measurements becomes comparable to, and even smaller than, that of higher-order aberrations.

IOTA: recent technology and science

“…With the help of an NSF grant to upgrade system components at IOTA, we recently installed a new star-tracker CCD camera that was built to our specifications at MIT Lincoln Laboratories. The new system, called LLiST, is described in this volume by Schuller et al 26 Our goals in replacing our previous camera with LLiST were to obtain increased quantum efficiency, faster read-out speed, and lower read noise. The advantages we expect to gain are a greater dynamic range in star brightness and read-out speed, both of which are important for the large range of stars and conditions at IOTA.…”