Gemini North Laser Guide Star System:Operations and maintenance review.

摘要

The Gemini North telescope has been providing Laser Guide Star Adaptive Optics (LGS AO) regular science queue observations for worldwide astronomers since February 2007. In this paper we comment on the reliability of the Laser Guide Star Facility high-power solid-state laser during normal operations, and discuss progress made on various issues that will enable a "turn-key" operation mode for the laser system. In this effort to produce consistent, stable and controlled laser parameters (power, wavelength and beam quality) we completed a failure mode effect analysis of the laser system and sub systems that initiated a campaign of hardware upgrades and procedural improvements to the routine maintenance operations. These upgrades are discussed, including pump laser diode replacements, as well as sum frequency generation (SFG) crystal degradation along with our detailed plans to improve overall laser reliability, and availability. Finally, we provide an overview of normal operation procedures during LGS runs and present a snapshot of data accumulated over several years that describes the overall LGS AO observing efficiency at the Gemini North telescope.