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
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GeminiFocus
January 2020 / 2019 Year in Review