Update on New GMOS-S CCDs

The upgrade of the GMOS-S CCD is ongoing. As mentioned in previous updates, the central CCD (CCDg) had experienced performance issues after unexpected cooling loss and subsequent warm-ups. The decision was made to replace it with a spare CCD of the same type. A second available CCD spare was also chosen as a replacement for the original CCDr, which had presented random CTE issues in the past. After a quick characterization, the two spares were found to meet specifications for noise, linearity, full well, and dark current. Therefore, the new focal plane assembly contains the two new spares and the original CCDb. It is currently installed in the instrument awaiting the alignment checks (currently on hold until normal operations are resumed).