SPIE Volume: 2198, Paper:81, pp.1202-1213
NICMOS: the next U.S. infrared space mission
Author(s): Rodger I. Thompson, Univ. of Arizona Steward Observatory, Tucson, AZ, USA.
Abstract: The near IR camera and multi-object spectrometer (NICMOS), is a new instrument for the Hubble Space Telescope (HST). NICMOS provides opportunities for near IR astrophysical investigations with HST in the 0.8 - 2.5micron spectral region. NICMOS contains three cameras at different spatial resolutions for imaging, grisms for multi-object spectroscopy, polarizers for polarimetry, and a coronagraphic spot and mask for coronagraphic imaging. A solid nitrogen dewar maintains the three 256 x 256 pixel HgCdTe detectors at their operating temperature of 58K for five years. NICMOS is the next US IR space mission, scheduled on STS Mission 91 in March 1997. It is anticipated that the European ISO mission will be launched and operational by that time and that joint observational programs with the two instruments will be possible.
SPIE Volume: 2209 Paper:39, pp.319-330
Near infrared camera and multiobject spectrometer (NICMOS): the near infrared space mission on HST
Author(s): Rodger I. Thompson, Univ. of Arizona, Tucson, AZ, USA.
Abstract: The Near Infrared Camera and Multi-Object Spectrometer (NICMOS), is a `second generation' instrument for the Hubble Space Telescope (HST). As such it is an integral part of the HST mission concept of periodic instrument replacement. NICMOS provides a new capability of near infrared astrophysical investigations in the 0.8 - 2.5 micron spectral region utilizing three cameras at different spatial resolutions for imaging, grisms for multi-object spectroscopy, polarizers for polarimetry,and a coronagraphic spot and mask for coronagraphic imaging. NICMOS has a five year mission lifetime with a solid nitrogen dewar that maintains the three 256x256 pixel HgCdTe detectors at the operating temperature of 58 Kelvin. Insertion of NICMOS is scheduled for STS Mission 91 in March 1997. The NICOS design is a result of the opportunities and constraints of the HST program which has a unique concept; periodic enhancement of the instrumental capabilities on orbit. This concept, closer to traditional ground based operations, provides a very cost effective capability for new space science opportunities and poses unique challenges in the instrument concepts produced to take advantage of the opportunities.
SPIE Volume: 1946 Paper:24, pp.214-224
Characterization of NICMOS detectors for space astronomy
Author(s): Marcia J. Rieke, Steward Observatory/Univ. of Arizona, Tucson, AZ, USA;
Gregory S. Winters, Steward Observatory/Univ. of Arizona, Tucson, AZ, USA;
James Cadien, Steward Observatory/Univ. of Arizona, Tucson, AZ, USA;
Robert W. Rasche, Steward Observatory/Univ. of Arizona, Tucson, AZ, USA.
Abstract: The NICMOS camera to be used on the Hubble Space Telescope will acquire near-infrared images with extremely high spatial resolution. To extract scientifically useful data from these images will require a complete understanding of the arrays used to produce the images. The NICMOS team has developed a program for characterizing arrays which will lead to this understanding and which will also allow selection of optimum devices for each section of the NICMOS instrument. The overall plan will be described and related to the scientific goals of NICMOS. The characterization plan includes standard infrared array testing such as electrical properties, read noise, dark current, and quantum efficiency, and will be expanded to include testing such as crosstalk measurements, hysteresis testing, and radiation testing.!
SPIE Volume: 1946 Paper:21, pp.179-187
Ground-based camera experience with NICMOS arrays
Author(s): Marcia J. Rieke, Steward Observatory/Univ. of Arizona, Tucson, AZ, USA;
George H. Rieke, Steward Observatory/Univ. of Arizona, Tucson, AZ, USA;
Elizabeth M. Green, Steward Observatory/Univ. of Arizona, Tucson, AZ, USA;
Earl F. Montgomery, Steward Observatory/Univ. of Arizona, Tucson, AZ, USA;
Craig L. Thompson, Steward Observatory/Univ. of Arizona, Tucson, AZ, USA.
Abstract: Several cameras employing NICMOS2 (128x128) and NICMOS3 (256x256) arrays have been used in diverse applications on ground-based telescopes. Such use of arrays provides many insights to their performance that are not usually obtained in laboratory tests, and provides a baseline of performance over repeated thermal cycles. Astronomical use of these arrays also involves extracting accurate photometric information and detection of sources in spite of high background levels. The NICMOS arrays have proven very capable as astronomical imagers.
SPIE Volume: 1946 Paper:20, pp.170-178
Low-noise performance and dark-current measurements on the 256x256 NICMOS3 FPA
Author(s): Donald E. Cooper, Rockwell International Science Ctr., Newbury Park, CA, USA;
Duc Q. Bui, Rockwell International Science Ctr., Thousand Oaks, CA, USA;
Robert B. Bailey, Rockwell International Science Ctr., Thousand Oaks, CA, USA;
Lester J. Kozlowski, Rockwell International Science Ctr., Thousand Oaks, CA, USA;
Kadri Vural, Rockwell International Science Ctr., Thousand Oaks, CA, USA.
Abstract: The NICMOS3 infrared focal plane array (FPA), which was designed as a Hubble Telescope upgrade device, provides excellent low-noise images in the 1 - 2.5micron (SWIR) band. Both the detector array and the readout multiplexer of this hybrid FPA are optimized for low-noise operation. The NICMOS detector array is fabricated in HgCdTe grown on a sapphire substrate (PACE-I material). The sapphire substrate is very rugged and provides a good thermal contraction match to the silicon multiplexer, producing excellent reliability. The composition of the HgCdTe is adjusted to yield a response cutoff at 2.5micron which limits the detector response to thermal background from the atmosphere and telescope. The quantum efficiency of the detectors is %GRT 50% over the 1 - 2.4micron range. The dark current of the NICMOS detector is < 1 e- at 77 K, which is unprecedented for an IR detector. The multiplexer is a switched-FET CMOS design with a single source-follower per unit cell. The photocurrent is integrated on each detector diode, and the diode integrated on each detector diode, and the diode voltage level can be read nondestructively, or reset after each readout. This flexibility in the FPA operation makes it possible to generate images at a 12 Hz data frame rate or to optimize for low-noise exposures of many thousands of seconds. With a readout before and after each reset, off-chip correlated double sampling can be implemented to reduce the read noise to < 30 e-
SPIE Volume: 1946 Paper:22, pp.188-198
NICMOS flight FPA qualification program
Author(s): Arvel D. Markum, Rockwell International Corp., Anaheim, CA, USA;
Karen A. Kormos, Rockwell International Corp., Anaheim, CA, USA;
Jere B. Edwards, Rockwell International Corp., Anaheim, CA, USA.
Abstract: A comprehensive program has been developed for the production of focal plane assemblies (FPA) for use on the University of Arizona Near Infrared Camera and Multi-Object Spectrometer (NICMOS) instrument which is to be installed in the Hubble Space Telescope (HST). This paper describes the current schedule, tests to be performed, test conditions and unique test facilities of the flight FPA qualification test program. This test series is intended to validate design, assembly, performance and reliability of flight qualified FPAs. Also described are the design features, performance characteristics and test results obtained with prototype FPAs used as engineering evaluation units prior to committing the flight qualification units to manufacture. The qualification tests will demonstrate performance margins over and above requirements under operating environmental conditions. Included in the qualification tests are electrical, mechanical and thermal tests. Random vibration tests and mechanical shock tests will be performed at 1.5 times the load level specified for acceptance requirements. The random vibration tests simulate launch conditions and will induce stresses to uncover any potential structural deficiencies that might exist. The mechanical shock tests will simulate potential impacts incurred as a result of handling or transport. The qualification test program is intended to maximize confidence in the quality and integrity of the flight FPAs.
SPIE Volume: 1945 Paper:41, pp.371-382
NICMOS flight focal plane assembly
Author(s): Lloyd Shin, Rockwell International Corp., Anaheim, CA, USA;
Gregory S. Winters, Steward Observatory/Univ. of Arizona, Tucson, AZ, USA.
Abstract: This paper discusses the mechanical design and assembly of the Near Infrared Camera and Multi- Object Spectrometer (NICMOS) focal plane assembly (FPA). The FPA consists of a mercury- cadmium-telluride (MCT) detector array hybridized to a silicon multiplexer (MUX), a sapphire carrier, an alumina ceramic multi-layer board (CMLB) including electrical components, a base plate, and flex cables. The FPA is designed for the following conditions; (1) shock and vibration during launch, (2) Coefficient of Thermal Expansion (CTE) of dissimilar materials at cryogenic temperature, (3) outgassing limitations to meet NASA's specifications, and (4) optical assembly tolerances. Also, the FPA is designed to be easily integrated into its dewar with provisions for mechanical as well as optical alignment. The FPA is assembled by building up two subassemblies in a parallel path, and then integrating the two subassemblies with the flex cables for the final assembly. These procedures are described in this paper, including alignment tolerances required and measured.
SPIE Volume: 1946 Paper:19, pp.161-169
NICMOS flight hardware 256 x 256 MCT detector array configuration
Author(s): John G. Poksheva, Rockwell International Corp., Anaheim, CA, USA;
Mark C. Farris, Rockwell International Corp., Anaheim, CA, USA;
Stephanie E. Tallarico, Rockwell International Corp., Anaheim, CA, USA.
Abstract: Features of the flight hardware version of the NICMOS 256x256 mercury-cadmium-telluride (MCT) detector array for the Hubble Space Telescope (HST) are presented and described. Detector flowdown requirements for flight production are reviewed and discussed. Detector cross section and array architecture features are analyzed in relation to quantum efficiency and crosstalk behavior. Features of the charge integration scheme employed are analyzed in assessing dynamic range.
SPIE Volume: 1946 Paper:25, pp.225-236
NICMOS3 detector testing: methods and results
Author(s): William K. Smith, Rockwell International Corp., Anaheim, CA, USA;
Ann B. Krueger, Rockwell International Corp., Anaheim, CA, USA;
Gregory S. Winters, Steward Observatory/Univ. of Arizona, Tucson, AZ, USA.
Abstract: A program is currently in process at Rockwell for the production of focal plane assemblies (FPA) for use on the University of Arizona Near Infrared Camera, Multi-Object Spectrometer (NICMOS) instrument which is to be installed in the Hubble Space Telescope (HST) during a Space Shuttle mission in 1997. This paper describes the testing approach for the production of the FPA's, the tests to be performed, the test equipment, and facilities used in the built of two prototype FPA's used as engineering evaluation units (EEU). A sample of the data output from the various tests will be discussed for one of the EEU FPA's, both in the intermediate screen tests which will be described, and for the final performance tests.
SPIE Volume: 1945 Paper:42, pp.383-389
Optical design of NICMOS: the second-generation infrared
instrument for the Hubble Space Telescope, pp.383-389
Author(s): Eric Ramberg, Ball Aerospace Systems Group, Boulder, CO, USA.
Abstract: NICMOS is the near infrared second generation instrument for the Hubble Space Telescope. The NICMOS instrument consist of three infrared cameras with spectral response between 1 and 2.5 micrometers whose fields of view are 11, 19.3 and 51.1 arc seconds. Each camera has an independent filter wheel with 20 positions. In the wide field camera, two grisms will be substituted for two of the filters. Some unique challenges arise because (1) NICMOS must interface with HST, (2) it is a low background infrared device with warm optics and (3) it has a large cryogenic dewar enveloping the detectors. This paper summarizes the optical configuration of the instrument as well as some of the requirements that drive the design. Expected performance will be presented.
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