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