GeminiFocus July 2017 - Page 18

Figure 2. GHOST team in North Ryde, Australia. Clockwise around the table: Jon Nielsen, Tony Farrell, Peter Young, Jennifer Dunn, Steve Margheim, Vlad Churilov, Ross Zhelem, Mick Edgar, Lew Waller, Richard McDermid, John Bassett, Greg Burley, Mike Ireland, and John Pazder. Photo credit: David Henderson GHOST’s Upcoming Test Phase Planned The Gemini High-resolution Optical SpecTro- graph (GHOST) project continues to move forward during the project build phase. In mid-May, representatives from all four orga- nizations involved with GHOST met at the Australian Astronomical Observatory (AAO) in North Ryde, Australia, to plan the upcom- ing test phase of the project (Figure 2). This was the first large-scale meeting of the proj- ect members since the critical design review in early 2016, and was considered a very pro- ductive week. Figure 3. At the end of the year we intend to move parts of GHOST to Gemini South for testing, including the AAO-built Cassegrain unit (part of which is seen in Figure 3), and pro- totype optical cable assembly. AAO plans to send the slit viewing assembly and sci- ence-grade optical cable shortly thereafter. The controlling computer, loaded with soft- ware from the Australian National Univer- sity, will go to the National Research Coun- cil Canada-Herzberg in Victoria, Canada, for integration with the spectrograph and thermal enclosure built there. Meanwhile, multiple suppliers are processing the many spectrograph optics, such as the GHOST col- limator mirror (Figure 4). A little over a year from now, these assemblies are slated to ship from Canada to Chile, where they will be cou pled with the Cassegrain unit. Once completed, GHOST begins testing and com- missioning on the Gemini South telescope. — David Henderson Gemini South Laser Nears Installation GHOST Integral Field Unit positioner assembly, which is part of the Cassegrain unit, in the AAO lab. Photo credit: AAO Progress continues for the new Toptica laser for the Gemini Multi-conjugate adaptive op- tics System (GeMS). Toptica staff in Munich, Germany, recently found the source of the bug that was causing an intermittent Inter- lock error. On June 20th, the laser passed the post-shipping acceptance testing. The laser is expected to be installed in early August, with on-sky commissioning to follow in the last week of October. Figure 4. In early May, an initial version of the Experi- mental Physics and Industrial Control Sys- tem (EPICS) code of the Toptica Laser Inter- lock System (TLIS) completed successful lab testing. The TLIS is an important safety sys- tem required to operate the Toptica laser at Gemini South. GHOST collimator mirror after aspheric polishing. Photo credit: Precision Asphere, Inc. 16 GeminiFocus July 2017