GeminiFocus 2019 Year in Review | Page 66

JULY 2019 Figure 3. Gemini North engineer John White working on the CCD focal plane array just prior to replacing the electronics board. Credit: Luc Boucher Figure 4. Gemini staff share information with CASCA participants in the June meeting in Montréal. GMOS-South CCD Intervention The Gemini Multi-Object Spectro- graph (GMOS) at Gemini South has, for some time, suffered from instabilities in the charge-coupled device (CCD) readout. Since the installation of the Hamamatsu CCDs, they have been performing sub-optimally. In particu- lar, we have seen instances where the charge transfer efficiency became too large, causing smearing on the im- ages, which affects the popular Nod & Shuffle mode of the instrument. We have been planning to tackle this issue by changing the existing electronics board inside the cryostat with one of a better design. This design has been proven to work for the GMOS instrument at Gemini North, which does not experience the same smearing effect. The critical and very sensitive intervention was carried out in June (Figure 3). The technical interven- tion went very well, and the lab tests quickly showed very promising results. GMOS-S was put back in normal operation and the effect of charge smearing has not been seen again. The CCD array performs to specification. Gemini Planet Imager Temporarily in Lab for Testing Recently the Gemini Planet Imager devel- oped a problem with its Micro-Electrical Mechanical System deformable mirror. In- vestigations in the lab have indicated that a critical electronics board related to the power supply has failed. Repairs are under- way, and in the meantime, the instrument will remain in the lab and unavailable for science. CASCA 2019 meeting in Montréal Gemini staff participated in the 2019 CASCA (Canadian Astronomical Soci- ety/Société Canadienne d’Astronomy) meeting in Montreal, which was held at McGill University from June 17-21 (Fig- ure 4). Besides hosting a booth in col- laboration with the Canadian Gemini Office (Stéphanie Côté, Joel Roediger, and Tim Davidge), we were available 64 GeminiFocus January 2020 / 2019 Year in Review