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NOAO Instrumentation News (1Sep95)
(from Director's Office, NOAO Newsletter No. 43, September 1995)

The third quarter showed steady progress on the projects in the
Instrument Projects Group. Priority for allocation of resources is
given to those closest to completion. We should see substantial
additions to the complement of instruments available to NOAO users
over the course of the next year.

The conversion of the Hydra fiber positioner and bench spectrograph
for use at the WIYN telescope is in the final stages of completion.
Activities in the third quarter were largely based on experience
during commissioning of the instrument at the telescope. Shared risk
scientific use will be starting on the timescale of publication of
this Newsletter. The remaining task is commissioning of the
all-transmissive camera. Efforts are underway to optimize the focus of
the camera specifically for the curvature of the SITe CCD that serves
as the dedicated detector. That final stage of the project is on track
for completion this fall. Project Scientists, Sam Barden and Taft
Armandroff, are collaborating with the CTIO staff and the Hydra
engineering team to plan for an implementation of Hydra at the R-C
focus of the CTIO 4-m telescope.

As discussed in the March Newsletter ("Special Opportunities for High
Spatial Resolution IR Imaging Programs"), the experience of the DLIRIM
experiment has now been translated into a hardware realization. The
goal was rapid framing of an InSb array, using image centroid
information to shift and add the accumulated frames. The DLIRIM
experiment showed that a software-based version of the scheme could
achieve 4mm imaging with good Strehl ratios (near diffraction-limited
performance) at the Mayall 4-m telescope.  The camera is the Cryogenic
Optical Bench (COB), retrofitted with 1:1 optics yielding ~0.1"/pixel
and a 25" field of view. Commercial Datacube hardware and software has
been interfaced successfully with the Wildfire system to accomplish
the shift and add accumulation on-board the controller system. An ICCD
camera and dichroic beam feed provide on-axis guiding. As of this
writing, the system has been successfully assembled. Project
Scientists Ian Gatley and Mike Merrill are awaiting its first
commissioning run once the KPNO 4-m is reassembled from shutdown.

The high-resolution infrared spectrograph, Phoenix, is the highest
priority major project currently in fabrication. Phoenix will offer
resolutions of 67,000-100,000 in the 1-5um range. It records a single
order of a large (8 x 16 inch), coarsely ruled echelle, selected by
narrow-band order sorting filters. Its use at longer wavelengths
requires cooled foreoptics that provide a Lyot stop to mask the
thermally emitting profile of the telescope. The instrument will be
shared between CTIO and KPNO on the 4-m telescopes; it can also be
accommodated on the KPNO 2.1-m. It has been requested as an
NOAO-supplied instrument for the Gemini telescopes. The large dewar
has been fabricated, welded and anodized; vacuum testing and minor
rework will assure the integrity of the vacuum. The clean room in the
IR lab is being expanded and renovated for full system integration.
The project is still on track for telescope commissioning early next
calendar year under the leadership of Project Scientist Ken Hinkle.

The Large CCD Mosaic Imager is in the final design and early
fabrication stages. This imager will have an 8192 x 8192 pixel format,
with an active area of over 12 cm on a side, and minimum gaps between
the three-side buttable 2K x 4K CCDs. The dewar and filter transport
mechanisms are well into the detail design phase. A major issue this
past quarter has been accommodation at the Prime Foci of the 4-m
telescopes. Questions requiring particular attention have been the
weight moving capacity of the pedestal drives, and the hardware for
installation and handling. A strong effort is underway at CTIO to
produce the ARCON hardware and adapt its software for use with Mosaic.
Schedule drivers for scientific use at the 4-m telescopes may turn out
to be the vendor-supplied items: the lenses and prisms for the new
KPNO Prime Focus Corrector (to supply adequate back focal distance),
and a sufficient quantity of scientific grade thinned CCDs. Since the
unit CCDs are interchangeable, the quality of the imager is likely to
be steadily upgraded as better devices become available. The
instrument is on track for commissioning on the KPNO 0.9-m during the
summer of 1996. Project scientists are Todd Boroson and Taft
Armandroff.

The last Newsletter discussed the results of the GRASP Preliminary
Design Review. GRASP will be a simultaneous four-color near-IR imager
and spectrograph, based on the SQIID heritage. A major recommendation
of the committee was a limit on the weight and volume of the
instrument. Meeting that recommendation has been the fundamental
design challenge of the GRASP team in the last quarter, under the
leadership of Dick Joyce. The desires for field of view and image
quality provide a major challenge for optical design and create a
decided tension with the need for compact packaging and maintenance
accessibility. Explorations of optical redesign, scale changes, and
packaging innovation are converging to a manageable solution. The
Delta-PDR will be rescheduled from its original summer date as soon as
an acceptable design configuration is well in hand.

There are new projects on the horizon for work in fiscal year 1996.
Near the end of spring semester, COB will be decommissioned from its
high resolution use on the KPNO 4-m. The detector will be upgraded to
a 1024 x 1024 InSb ALADDIN array with associated controller. The
instrument will then be deployed at CTIO, along with the tip-tilt f/14
secondary on the 4-m telescope, for regular use as a high-resolution
imager. At the same time, it is anticipated that the ALADDIN
development project will produce a number of partially functioning
arrays for use at NOAO. We intend to install usable 512 square InSb
arrays into SQIID over the next year, and recommission that instrument
for use on the KPNO 4-m. It should serve many of the community's IR
imaging needs during the interval in which GRASP is being developed
and fabricated. In addition, design work will begin in earnest on the
Gemini Infrared Spectrograph and its copy for CTIO and Gemini South.

As always, your input is vital to the forward look and shape of the
NOAO instrumentation program. Please contact me or any of the project
scientists with your suggestions.

Richard Green

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