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AUSTRALIAN
NATIONAL UNIVERSITY System Design Note 4.14 Created: 8 September 2001 Last modified: 8 September 2001 |
NIFS NOMENCLATURE
Jan van Harmelen
Research School of Astronomy
and Astrophysics
Institute of Advanced
Studies
Australian National
University
Revision History
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Revision No. |
Author & Date |
Approval & Date |
Description |
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Revision 1 |
Jan van Harmelen 21 February 2001 |
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Original document. |
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Revision 2 |
Jan van Harmelen 27 February 2001 |
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Added “Image Stacker” |
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Revision 3 |
Peter J. McGregor 05 September 2001 |
Peter J. McGregor 05 September 2001 |
Revised following CDR. |
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Contents
4.1.2 Cryostat
Support Brackets
4.1.4.1 Components
Controller Thermal Enclosure
4.1.4.2 Detector
Controller Thermal Enclosure
4.2.9 On
Instrument Wavefront Sensor
4.2.10.4.2 OIWFS
Test Projector
4.2.10.11
Collimator Mirror Tower
4.2.10.12
Collimator Corrector Tower
4.2.10.12.1
Collimator Corrector
4.2.10.16
Spectrograph Detector
4.2.10.17 Detector
Support Tower
4.2.10.19 Detector
Mounting Board
4.2.10.20 Detector
Flex Circuits
1 Purpose
This document defines standard nomenclature to be used in referring to the various components of the Gemini Near-infrared Integral Field Spectrograph (NIFS). The nomenclature defined in this document should be used in all NIFS documents so as to avoid confusion and ambiguity.
2 Applicable Documents
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3 Introduction
The Gemini Near-infrared Spectrograph (NIFS) contains a variety of unique components. Some of these components have a heritage from the Gemini Near-InfraRed Imager (NIRI). Others are unique to NIFS. In order to unambiguously describe these components and their relationships to each other, it is necessary to define standard nomenclature that should be used in all NIFS documents. This documents makes those definitions.
4 Definitions
The whole instrument is referred to as NIFS, or the Near-infrared Integral Field Spectrograph.
4.1 Auxiliary Systems
4.1.1 ISS Interface Plate
The Instrument Support Structure (ISS) interface plate is the plate that attaches to the ISS. The cryostat is mounted on the ISS interface plate via the cryostat support brackets. The integration frame is also mounted on the ISS interface plate, in a way that does not load the cryostat.
4.1.2 Cryostat Support Brackets
The cryostat support brackets are the four triangular brackets used to attach the cryostat to the ISS interface plate.
4.1.3 Integration Frame
The integration frame is the structure carrying the thermal enclosures and mounted on the ISS interface plate.
4.1.4 Thermal Enclosures
The thermal enclosures are the two thermally controlled electronics cabinets that are carried by the integration frame. The are two thermal enclosures.
4.1.4.1 Components Controller Thermal Enclosure
The Components Controller (CC) thermal enclosure is the thermal enclosure containing the mechanism and temperature control hardware.
4.1.4.2 Detector Controller Thermal Enclosure
The Detector Controller (DC) thermal enclosure is the thermal enclosure containing the detector controller hardware.
4.1.5 Ballast Weights
The ballast weights are the lead weights that attach to the integration frame to achieve the require center of gravity and total mass.
4.2 The Cryostat
4.2.1 Cryostat
The cryostat is the entire cryogenic vacuum vessel that consists of the vacuum jacket, cryocoolers, spectrograph, and On-Instrument Wavefront Sensor (OIWFS).
4.2.2 Vacuum Jacket
The vacuum jacket is the outer vessel that maintains the cryostat vacuum.
4.2.3 Environmental Cover
The environmental cover is the mechanism mounted in front of the cryostat windows on the outside of the cryostat. It consists of a dust cover and a dry air manifold to ensure that the cryostat window remains dust free.
4.2.4 Cryocoolers
The cryocoolers are the Coolpower 130 cold heads that keep the instrument cold. They form part of a closed-cycle system consisting for the helium compressors, helium lines, and the cold heads.
4.2.5 Floating Shields
The floating shields are the insulated plates suspended from the inside surface of the vacuum jacket between the vacuum jacket and the radiation shields. The floating shields stabilize at an intermediate temperature so lower the radiative heat load.
4.2.6 Titanium Tines
The titanium tines are the three "V" shaped trusses that hold the cold work surface plate within the cryostat. The titanium tines attach the inside surface of the vacuum jacket. They form the main mechanical thermal path between the room temperature and cold components of the cryostat.
4.2.7 Cold Work Surface Plate
The cold work surface plate is the 40 mm thick hexagonal plate mounted from the titanium tines inside the cryostat. It is the main structural and thermal component in the cryostat.
4.2.8 Radiation Shields
The radiation shields are the plates that form the outer surface of the cold components within the cryostat. The spectrograph radiation shield and the OIWFS radiation shield mount separately to the cold work surface plate.
4.2.9 On Instrument Wavefront Sensor
The OIWFS is the guiding camera attached to one side of the cold work surface plate. The OIWFS is used to track slow flexure changes and fast tip-tilt and focus changes. The NIFS OIWFS is a duplicate of the NIRI OIWFS. To avoid confusion, UH nomenclature for all of the OIWFS components should be used.
4.2.9.1 Optable
The optable is the main housing of the OIWFS. The optable is attached to the OIWFS side of the cold work surface plate. OIWFS components mount in or on the outer face of the optable.
4.2.9.2 Photon Shields
The photon shields are the light-tight baffles attached to the cold work surface plate and OIWFS optable that prevent stray light entering the OIWFS spaces.
4.2.9.3 Gimbal Mirror
The gimbal mirror is the X-Y steerable mirror used to select the OIWFS star. It is located at the first pupil in the OIWFS optical train.
4.2.9.4 Shack-Hartmann Prism
The Shack-Hartmann prism is the dual-faceted prism located at the second pupil in the OIWFS optical train. It splits the beam equally to form two images of the OIWFS guide star on the OIWFS detector. The positions of these images in the focal plane monitor tip-tilt (tracking). The separation of the two images monitors focus, in one direction only.
4.2.10 Spectrograph
The spectrograph is the NIFS science instrument attached to the other side of the cold work surface plate.
4.2.10.1 Spectrograph Skirt
The spectrograph skirt is the hexagonal baffle attached to the spectrograph side of the cold work surface plate to which the spectrograph cover is attached. The spectrograph skirt and the spectrograph cover form the structural box in which the spectrograph is mounted.
4.2.10.2 Spectrograph Cover
The spectrograph cover is the plate over the top of the spectrograph. The spectrograph cover is attached to the spectrograph skirt. Most of the spectrograph components are attached to both the cold work surface plate and the spectrograph cover.
4.2.10.3 Focal Plane Unit
The focal plane unit is the module consisting of the pick-off probe, focal plane mask wheel, focal converter, and cold stop.
4.2.10.4 Pick-Off Probe
The pick-off probe is the arm that extends into the telescope beam above the OIWFS to deflect the science field to the spectrograph.
4.2.10.4.1 Pick-Off Mirror
The pick-off mirror is the mirror on the pick-off probe.
4.2.10.4.2 OIWFS Test Projector
The OIWFS test projector is the light source located in the pick-off probe that directs a fake star image to the OIWFS.
4.2.10.5 Focal Plane Wheel
The focal plane mask wheel is the mechanism that positions masks (clear, occulting disks, calibration masks) at the folded telescope focus.
4.2.10.6 Focal Converter
The focal converter is the mirror in the focal plane unit that converts the f/16 telescope beam to the f/256 beam that is passed to the image slicer.
4.2.10.7 Cold Stop
The cold stop is the background baffle located at the pupil image formed by the focal converter.
4.2.10.8 Filter-Fold Tower
The filter-fold tower is the module that contains the filter wheel and the first and second fold mirrors. The filter-fold tower attaches to the cold work surface plate and the spectrograph cover.
4.2.10.8.1 Filter Wheel
The filter wheel is the mechanism that inserts order blocking filters into the beam.
4.2.10.8.2 First Fold Mirror
The first fold mirror is the first flat mirror that folds the f/256 beam towards the image slicer.
4.2.10.8.3 Second Fold Mirror
The second fold mirror is the second flat mirror that folds the f/256 beam towards the image slicer.
4.2.10.9 Integral Field Unit
The integral field unit is the optical system that reformats the input science field into a staircase slit and directs it towards the grating. The integral field unit consists of the image slicer and the image stacker.
4.2.10.9.1 Image Slicer Tower
The image slicer tower is the module containing the image slicer. The image slicer tower attaches to the cold work surface plate and the spectrograph cover.
4.2.10.9.2 Image Slicer
The image slicer is the stack of 29 slitlet mirrors that fan the field towards the pupil mirror array.
4.2.10.9.3 Image Stacker
The image stacker is the module comprised of the pupil mirror array, the field mirror array, and their mounting frame. The image stacker forms the staircase slit image and directs it towards the grating.
4.2.10.9.4 Pupil Mirror Array
The pupil mirror array is the monolithic array of 29 toroidal mirrors located at the pupils formed by the image slicer mirrors. The pupil mirrors reimage the focal plane at the field mirror array as a staircase slit.
4.2.10.9.5 Field Mirror Array
The field mirror array is the monolithic array of 29 mirrors located at the staircase slit image. The field mirrors form a single pupil on the grating.
4.2.10.10 Tri-Fold Tower
The tri-fold tower is the module that containing the image stacker and the tri-fold mirror. The tri-fold tower attaches to the cold work surface plate and the spectrograph cover.
4.2.10.10.1 Tri-Fold Mirror
The tri-fold mirror is the tri-faceted mirror near the image stacker. The trifold mirror fold three different sections of the spectrograph optical path so that it fits within the NIRI duplicate cryostat.
4.2.10.11 Collimator Mirror Tower
The collimator mirror tower is the module that containing the collimator mirror. The collimator mirror tower attaches to the cold work surface plate and the spectrograph cover.
4.2.10.11.1 Collimator Mirror
The collimator mirror is the large spherical mirror that collimates the beam passing to the grating.
4.2.10.12 Collimator Corrector Tower
The collimator corrector tower is the module that containing the collimator corrector. The collimator corrector tower attaches to the cold work surface plate and the spectrograph cover.
4.2.10.12.1 Collimator Corrector
The collimator corrector is the lens that corrects spherical aberration in the Bouwers collimator.
4.2.10.13 Grating Turret
The grating turret is the carousel on which the gratings are mounted.
4.2.10.13.1 Gratings
The gratings are the diffraction gratings mounted on the grating turret.
4.2.10.13.2 Grating Drive
The grating drive is the stepper motor, gear train, and encoders that drive the grating turret.
4.2.10.14 Flip Mirror
The flip mirror is the mirror that is inserted in front of the grating to image undispersed light of the input field. The flip mirror is used to acquire faint objects.
4.2.10.15 Camera
The camera is the spectrograph optical system that images dispersed spectra onto the science detector.
4.2.10.16 Spectrograph Detector
The spectrograph detector is the science detector.
4.2.10.17 Detector Support Tower
The detector support tower is the tower that carries the detector housing. It is separate from both the camera and the detector housing. The detector support tower attaches to the cold work surface plate and to the spectrograph cover.
4.2.10.18 Detector Housing
The detector housing is the box in which the detector mounting board is mounted.
4.2.10.19 Detector Mounting Board
The detector mounting board is the flexi-rigid printed circuit board on which the detector, detector socket, detector thermal mass, and pre-amplifiers are mounted.
4.2.10.20 Detector Flex Circuits
The detector flexible circuits are the flexible printed circuits used for connection between the detector housing and the hermetic connectors on the vacuum jacket.
Appendix A: List of Figures
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Figure 1 |
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