GeminiFocus April 2016 | Page 24

Figure 2. The Gemini South laser propagating prior to the September 2015 earthquake. GeMS Laser Progress Users of the Gemini Multi-conjugate adaptive optics System (GeMS) will know that the GeMS laser has caused significant issues over the past year, particularly since the earthquake of September 2015. Major efforts finally got us back to a working system (delivering 30 of its 50 watts, which is sufficient in good conditions) by the time of the February 2016 GeMS run. However, as the current laser (Figure 2) is not robust enough for regular operations, the process of finding a replacement system is now well under way. The National Science Foundation, in partnership with AURA/Gemini, has selected Toptica Photonics AG to produce a new laser for GeMS. The new laser will still produce the constellation of five artificial guide stars on which GeMS relies to provide excellent and stable image quality over the Gemini South Adaptive Optics Imager’s full field-of-view. We expect the new laser will be significantly more robust and reliable than the old one, removing what has been an achilles heel of GeMS in operation. Gen 4#3 The Gen 4#3 team has made steady progress in the past three months on crafting the Request for Proposals (RfP) for this next facility instrument. In their November 2015 meeting, the Gemini Board requested the Science and Technology Advisory Committee (STAC) review the outcomes of the Gemini Instrument Feasibility Studies and work with 22 GeminiFocus Gemini to identify core capabilities. The Board also placed a high priority on schedule and cost control. The STAC met in December and identified some expanded core capabilities for the Gen 4#3 instrument (viewable here). They also highlighted the importance of instrument throughput and operational efficiency. They agreed that schedule is a primary driver for Gen 4#3, and emphasized that Gemini should be fully prepared to use Gen 4#3 to take advantage of early Large Synoptic Survey Telescope (LSST) science. We are therefore driving the Gen 4#3 schedule to help ensure the instrument is commissioned by the planned start of LSST science operations. We still anticipate the release of the Gen 4#3 RfP in 2016Q2. GMOS CCD Issues While the Hamamatsu CCDs installed in GMOSSouth continue to perform well, the internal GMOS team encountered a few technical issues in preparing a similar system for GMOSNorth. Specifically, various controller and other electronic components have changed from the versions used in GMOS-S. As these changes are apparently causing some performance degradation, we have cancelled the planned 2016Q3 GMOS-N CCD installation. We will update our web pages as we develop a new timeline for installation, likely some time in early 2017. Additional information can be found on this webpage. April 2016