Gemini multi-object spectrograph focal plane CCD upgrade

The instrument group of the Herzberg Institute of Astrophysics has been commissioned by the Gemini Observatory to develop and implement a new focal plane assembly with an array of three Hamamatsu CCDs for the Gemini Multi- Object Spectrographs [1,2] . This paper describes the overall design of the new focal plane system with respect to the existing interface and requirements and outlines the test methodology to validate the new system against its performance requirements. The characterization and performance optimization processes of the Hamamatus CCDs are also described.