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AUSTRALIAN
NATIONAL UNIVERSITY System Design Note 5.01 Created: 11 April 2000 Last modified: 11 April 2000 |
NIFS LINEAR IFU OPTICAL DESIGN
Peter J. McGregor
Research School of Astronomy
and Astrophysics
Institute of Advanced
Studies
Australian National
University
Revision History
|
Revision No. |
Author & Date |
Approval & Date |
Description |
|
Revision 1 |
Peter J. McGregor 02 December 1999 |
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Original document. |
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Revision 2 |
Peter J. McGregor 11 April 2000 |
Jan van Harmelen 12 April 2000 |
Separated from concentric IFU description. Reformatted for Word 2000. |
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Contents
5.6.1 Mirror Array
Manufacturability
5.6.3 Lens Blank
Availability and Cost
Appendix A: NIFS
Linear IFU Design
1 Purpose
This document describes the linear IFU optical design option for the Gemini Near-infrared Integral-Field Spectrograph (NIFS).
2 Applicable Documents
|
Document
ID |
Source |
Title |
|
RSAA |
NIFS Optical Requirements |
|
|
RSAA |
NIFS Diffraction Analysis |
|
|
RSAA |
NIFS Optical Throughput |
|
|
RSAA |
NIFS Optical Design |
|
|
|
|
|
3 Introduction
The Gemini Near-infrared Integral-Field Spectrograph (NIFS) optical specification is described fully in SDN0005.00 (NIFS Optical Requirements). NIFS will use a reflective integral-field unit (IFU) to reformat a 3.0²´3.0² region of sky into a 64 mm long by 0.1² wide “staircase” pattern at the effective entrance “slit” of the NIFS spectrograph. The spectrograph will image this effective “slit” pattern onto two pixels at the science detector. The 29 spatial “slices” will be imaged onto the detector in a way which maintains their geometrical integrity of better than 1 pixel. The NIFS optics will degrade the Strehl ratio of the adaptive optics corrected image delivered by ALTAIR by no more than 20%. The optical design must prevent stray light from reaching the detector by providing both a cold aperture mask and a cold pupil plane mask (i.e., cold stop). Scattered light must be reduced to less than the detector dark current or the natural background flux. This is especially important for near-angle scattering which will scatter OH airglow line emission into nearby spectral regions.
NIFS is a fast-tracked instrument that will use a duplicate of the NIRI cryostat. Consequently, viable optical designs for NIFS must also meet the mechanical requirement that they can be folded to fit within the NIRI cryostat duplicate.
This document describes the linear IFU option for the NIFS optics and discusses its performance, manufacturability, and likely cost.
4 IFU Concept
The IFU is crucial to the performance of NIFS. An image slicer is located at an image plane. This consists of 29 thin rectangular slices, each rotated with respect to the input axis so that the output beams are spatially separated. A second mirror array is needed to control the apparent pupil positions of the 29 output beams. The geometry of the NIFS IFU is such that the footprints on these mirrors would overlap if they simply intersected f/16.2 light cones from flat image slicer mirrors. It is necessary to form separate pupils on each of the 29 elements of the pupil mirrors array to prevent this overlap. The elements of the pupil mirror array reimage the image slicer plane at the input focal ratio of the spectrograph. A third mirror array is required at the location of this image plane to direct the 29 individual pupils onto the grating. This is the field mirror array.
The angles at the image slicer would be excessive if it were operated at the f/16.2 focal ratio of the Gemini telescope. In practice, it is necessary to reimage the telescope focal plane onto the image slicer mirrors at a slow focal ratio. This reduces the off-axis angle, reduces the depth of defocus on the slicer mirrors, and increases their size which simplifies their manufacture.
While convenient for the image slicer, a slow focal ratio is not a convenient input to the NIFS spectrograph. A slow focal ratio requires a geometrically large reformatted slit and an excessively long collimator focal length. It is therefore convenient to use the pupil mirror array to reimage the reformatted slit at a modest focal ratio. This focal ratio defines the length of the effective input slit to the spectrograph, and hence it also defines the geometrical spacing of the field mirror array elements. This in turn defines the spacing of the pupil mirror elements for the particular IFU design philosophy.
The need to minimize off-axis angles makes it convenient to position the image slicer “out-of-plane” with respect to the pupil and field mirror arrays. It is of course also desirable to minimize this “out-of-plane” angle.
5 Linear IFU Design
5.1 Description
The optical design discussed here uses linear mirror arrays in which the vertices of the mirror elements are constrained to lie in one plane. It is our expectation that such a mirror array can be manufactured using a two-axis single-point diamond machine. In this design, configurations at the ends of each mirror array operate off-axis both in the spatial and spectral directions. It is not possible, in this arrangement, to locate the pupil images for each configuration precisely on the corresponding pupil mirror since the image slicer to pupil mirror distance is configuration dependent. These optical complexities must be tolerated in order to simplify the IFU mirror design.
A NIFS optical design based on the linear
IFU is shown in Figure 1. The mirror arrays are shown in Figure 2. The design uses an Offner relay to form a cold stop
and reimage the f/16.2 telescope focus at a convenient location. A focal ratio
converter mirror reimages this focus at f/160 onto the splayed spherical image
slicer mirrors. A focal ratio of f/160 is the largest that can be accommodated
simply within the confines of the duplicate NIRI cryostat. The spherical image
slicer mirrors form separate 1.333 mm diameter pupils near the individual 2.05
mm wide elements of the pupil mirror array. The pupil mirrors are toroidal and
decentered in the direction along the mirror array in order to focus rays at
near normal incidence onto the field mirrors. The toroidal pupil mirrors all
use a radius of curvature of 39.500 mm in the direction perpendicular to the
array to simplify manufacture. The radius of curvature in the array direction
is 38.900 mm for all pupil mirrors. The field mirrors are also toroidal and
decentered in the direction perpendicular to the mirror array in order to form
an appropriate grating pupil. This is required partly because the individual
pupils near the pupil mirror array are formed at different distances from the
field mirror array elements, and partly because the out-of-plane angle at the
pupil mirror array induces an apparent curvature in the sequence of pupil
images as seen from the field mirrors. Each of the toroidal field mirrors is
constrained to have a radius of curvature of 43.207 mm in the direction
perpendicular to the array in order to simplify manufacture.
Figure 1: NIFS linear IFU design.
Figure 2: NIFS linear IFU pupil mirror array (bottom) and field mirror array (top).
The reformatted slit image at the field mirrors is flat and the beams exiting the field mirror array are telecentric. This naturally leads to a refractive design for the spectrograph collimator. The collimator focal length is 500 mm. The spectrograph uses a five-element refractive Petzval camera with a focal length of 290 mm to form the spectral image on the detector.
5.2 Geometrical Performance
5.2.1 Image Quality
The geometrical image quality of the NIFS linear IFU design is shown in Figure 3, Figure 4, and Figure 5 for the top, center and bottom slicer configurations. The image quality is well within specification and only slightly inferior to that of the NIFS basline concentric IFU design (NIFS Optical Design, SDN0005.28).
Figure 3: NIFS linear IFU through focus spot diagrams for the top slice without diffraction effects. Five field positions along the slice are shown for the H grating. Boxes correspond to one pixel.
Figure 4: NIFS linear IFU
through focus spot diagrams for the center slice without diffraction effects.
Five field positions along the slice are shown for the H grating. Boxes correspond to one pixel.
Figure 5: NIFS linear IFU through focus spot
diagrams for the bottom slice without diffraction effects. Five field positions
along the slice are shown for the H
grating. Boxes correspond to one pixel.
5.2.2 Distortion
Distortion at the detector image plane has been determined from the X-Y coordinates of image centroids arising from known input field positions. These are plotted in Figure 6 where the positions of various slitlet images are shown as a function of position across the detector in the dispersion direction. Each set of slitlet positions is shown as deviations from the slitlet position at the central wavelength. The distortion along the spectrum for the extreme top and bottom slitlets amounts to ~ 3.5 pixels. This is symmetrical about the optical axis and arises in the spectrograph camera. The deviation from ideal of the position of each slitlet image in the spatial direction on the detector and at the central wavelength is shown in Figure 7. Distortion in the camera expands the spectral pattern on the detector by ~ 1.7 pixels in the spatial direction. Lower distortion can be achieved by re-optimizing the camera design.
Figure 6: NIFS linear IFU
distortion in the spatial direction for different configurations as a function
of wavelength in units of pixels at the detector.
Figure 7: NIFS linear IFU distortion in the spatial direction at the central wavelength for different configurations in units of pixels at the detector.
5.2.3 Throughput
The throughput budget for the linear IFU design is presented in Table 1. The total system throughput is similar to the baseline concentric IFU design (NIFS Optical Throughput, SDN0005.15), despite the additional surfaces required for the Offner relay included in the linear IFU design as presented.
Table 1: NIFS System Throughput Budget for the Linear IFU Design
|
Component |
Coating |
Transmission |
||
|
|
|
1.00mm |
1.65mm |
2.20mm |
|
|
|
|
|
|
|
Telescope Primary |
O/C Silver |
0.979 |
0.986 |
0.987 |
|
Telescope Secondary |
O/C Silver |
0.979 |
0.986 |
0.987 |
|
ISS Fold Mirror |
O/C Silver |
0.979 |
0.986 |
0.987 |
|
Cryostat Window |
CaF2/MgF2 |
0.949 |
0.960 |
0.955 |
|
Pick-Off Mirror |
Gold |
0.986 |
0.990 |
0.991 |
|
Offner Primary |
Gold |
0.986 |
0.990 |
0.991 |
|
Offner Secondary |
Gold |
0.986 |
0.990 |
0.991 |
|
Offner Primary |
Gold |
0.986 |
0.990 |
0.991 |
|
Filter |
… |
0.80 |
0.80 |
0.80 |
|
Fold Mirror |
Gold |
0.986 |
0.990 |
0.991 |
|
F/# Converter Mirror |
Gold |
0.986 |
0.990 |
0.991 |
|
Image Slicer: Reflectivity |
Gold |
0.986 |
0.990 |
0.991 |
|
Image Slicer: Diffraction |
… |
0.99 |
0.98 |
0.97 |
|
Pupil Mirror Array Mirror |
Gold |
0.986 |
0.990 |
0.991 |
|
Field Mirror Array Mirror |
Gold |
0.986 |
0.990 |
0.991 |
|
Field Lens 1 |
Sapph./Janos |
0.987 |
0.982 |
0.994 |
|
Field Lens 2 |
Silica/MgF2 |
0.950 |
0.951 |
0.950 |
|
Collimator Fold Mirror |
Gold |
0.986 |
0.990 |
0.991 |
|
Collimator Lens 1 |
Silica/MgF2 |
0.950 |
0.951 |
0.950 |
|
Collimator Lens 2 |
ZnSe/Janos |
0.994 |
0.998 |
0.986 |
|
Collimator Lens 3 |
BaF2/MgF2 |
0.948 |
0.966 |
0.958 |
|
Grating: Efficiency |
… |
0.75 |
0.75 |
0.75 |
|
Grating: Reflectivity |
Gold |
0.986 |
0.990 |
0.980 |
|
Camera Lens 1 |
CaF2/MgF2 |
0.949 |
0.960 |
0.955 |
|
Camera Lens 2 |
Silica/MgF2 |
0.950 |
0.951 |
0.950 |
|
Camera Lens 3 |
CaF2/MgF2 |
0.949 |
0.960 |
0.955 |
|
Camera Lens 4 |
ZnSe/Janos |
0.994 |
0.998 |
0.986 |
|
Camera Lens 5 |
Sapph./Janos |
0.950 |
0.951 |
0.950 |
|
Detector QE |
… |
0.518 |
0.583 |
0.623 |
|
|
|
|
|
|
|
TOTAL (without AO) |
|
0.159 |
0.201 |
0.205 |
|
|
|
|
|
|
|
ALTAIR |
|
0.773 |
0.825 |
0.843 |
|
TOTAL (with AO) |
|
0.123 |
0.166 |
0.173 |
5.3 Diffraction Performance
5.3.1 Image Quality
Diffraction at the image slicer broadens the beam in the spectral direction (NIFS Diffraction Analysis, SDN0005.06). The extent of the pupil image in this direction is approximately doubled. The effect of diffraction has been simulated by fully and uniformly illuminating the 32´60 mm rectangular grating pupil through an input at the image slicer. Aberrations in the telescope, Offner relay, and focal ratio converter are excluded. The beam envelope for the NIFS linear IFU design with this illumination is shown in Figure 8. The image quality of the NIFS linear IFU design with this illumination is shown in Figure 9, Figure 10, and Figure 11. The optical performance of the linear IFU design is significantly inferior to that of the baseline concentric IFU design when this larger diffracted beam is considered.
Figure 8: NIFS linear IFU design showing the diffracted beam envelope from the image slicer to the detector.
Figure 9: NIFS linear IFU
through focus spot diagrams for the top slice including the effects of
diffraction at the image slicer. Five field positions along the slice are shown
for the H grating. Boxes correspond
to one pixel.
Figure 10: NIFS linear IFU through focus spot diagrams for the center slice
including the effects of diffraction at the image slicer. Five field positions
along the slice are shown for the H
grating. Boxes correspond to one pixel.
Figure 11: NIFS linear IFU through focus spot diagrams for the bottom slice
including the effects of diffraction at the image slicer. Five field positions
along the slice are shown for the H
grating. Boxes correspond to one pixel.
5.4 Mechanical Layout
The mechanical layout of the NIFS linear IFU design in the duplicate NIRI cryostat is shown in Figure 12. The layout shows a schematic grating wheel and demonstrates how it will be possible to reuse the NIRI science detector focus mechanism, if necessary.
Figure 12: Mechanical layout of the NIFS linear IFU design within the duplicate NIRI cryostat.
5.5 Features
5.5.1 Focal Plane Mask Wheel
The Focal Plane Mask Wheel is located at the telescope focus, away from other optical elements. This provides adequate room for a duplicate NIRI mechanism.
5.5.2 Baffling
The NIFS linear IFU design incorporates an Offner relay with cold stop on the Offner secondary mirror to baffle the system well.
5.5.3 Filter Footprint
The Filter Wheel is located in the f/16.2 output arm of the Offner relay so the footprint on the filter has a diameter of > 10 mm.
5.5.4 Camera Optical Quality
The linear IFU design uses the long version of the Petzval camera which has better image quality than the shorter version of this camera.
5.6 Limitations
5.6.1 Mirror Array Manufacturability
The field mirror arrays are expected to be the most difficult to manufacture. Each mirror is decentered perpendicular to the array by up to 0.10 mm as listed in Table 2. A three-axis machine may be required to single-point diamond machine these surfaces. Manufacturing procedures need to be investigated further.
The different curvatures for the individual field mirrors means that the locations of the machined boundaries between the field mirrors may deviate from their design positions. The largest difference in radius of curvature occurs between configurations 10 and 11 (Table 2). The two surfaces differ in radius by 1.5 mm. They have equal sag at a position offset 9.1 mm from the nominal mirror boundary. This corresponds to an acceptably small 0.3 pixels referenced to the detector focus.
The toroidal surfaces of the decentered pupil mirrors can be fly-cut, but the deviation from the required surface will increase with increasing decenter. At the extreme X decenter of 2.8042 mm, the 2.048 mm wide fly-cut pupil mirror will deviate from the required sphere by up to 0.24 mm = lmin/3.86, where lmin = 0.94 mm. This is an acceptably small deviation.
Table 2: Individual Pupil and Field Mirror Parameters
|
Configuration |
Pupil Mirror X Decenter (mm) |
Field Mirror X Curvature (mm) |
Field Mirror Y Decenter (mm) |
|
|
|
|
|
|
-15 |
2.8042 |
44.4 |
0.09 |
|
-14 |
2.6197 |
44.0 |
0.09 |
|
-13 |
2.4347 |
43.0 |
0.08 |
|
-12 |
2.2492 |
42.5 |
0.08 |
|
-11 |
2.0633 |
42.0 |
0.07 |
|
-10 |
1.8770 |
41.0 |
0.06 |
|
-9 |
1.6903 |
41.0 |
0.06 |
|
-8 |
1.5033 |
41.0 |
0.05 |
|
-7 |
1.3161 |
40.5 |
0.04 |
|
-6 |
1.1285 |
40.0 |
0.04 |
|
-5 |
0.9408 |
40.0 |
0.03 |
|
-4 |
0.7528 |
39.5 |
0.02 |
|
-3 |
0.5648 |
39.5 |
0.02 |
|
-2 |
0.3766 |
39.5 |
0.01 |
|
-1 |
0.1883 |
39.5 |
0.01 |
|
0 |
0.0000 |
39.5 |
0.00 |
|
1 |
-0.1883 |
39.5 |
0.00 |
|
2 |
-0.3766 |
39.5 |
0.00 |
|
3 |
-0.5648 |
39.5 |
0.01 |
|
4 |
-0.7528 |
40.0 |
0.01 |
|
5 |
-0.9408 |
40.0 |
0.01 |
|
6 |
-1.1285 |
40.2 |
0.01 |
|
7 |
-1.3161 |
40.5 |
0.02 |
|
8 |
-1.5033 |
41.0 |
0.02 |
|
9 |
-1.6903 |
41.5 |
0.03 |
|
10 |
-1.8770 |
41.5 |
0.04 |
|
11 |
-2.0633 |
43.0 |
0.05 |
|
12 |
-2.2492 |
43.0 |
0.07 |
|
13 |
-2.4347 |
44.0 |
0.07 |
|
14 |
-2.6197 |
44.5 |
0.09 |
|
15 |
-2.8042 |
45.7 |
0.10 |
5.6.2 Alignment
The NIFS linear IFU design uses an f/160 image slicer which would be easier to align than the f/256 image slicer used in the baseline concentric IFU design. Image slicer alignment is further eased by using 1.333 mm diameter pupil images on 2.048 mm wide pupil mirrors in the linear IFU design. The pupil images are slightly out of focus on the pupil mirrors for off-axis configurations, so the beam footprint is large than 1.333 mm.
The field lens doublet in the collimator of the NIFS linear IFU design will vignette the folded beam if a circular lens is used. Both lenses can be conveniently trimmed top and bottom since the beam footprint is highly elongated. However, accurate alignment of the trimmed lenses may be difficult. Mounting arrangements for these lenses need to be investigated further.
5.6.3 Lens Blank Availability and Cost
The NIFS linear IFU design uses a refractive collimator with three elements having diameters of 110 mm. Procurement of BaF2 and ZnSe blanks of this dimension is a potential budget and schedule risk. The ZnSe lens, in particular, requires a 25 mm thick blank. The availability and cost of such blanks requires further investigation.
5.6.4 Grating Pupil
Diffraction smears the geometrical pupil. The optical design use a 32´60 mm grating to accommodate this larger pupil. Off-axis configurations in the NIFS linear IFU design do not form precise pupils on the grating. Motion of the pupil image on the grating is minimized by decentering the field mirrors. However, there is residual pupil image defocus which causes the extremities of the grating pupil images to fall off the grating for extreme off-axis configurations. This is expected to have minimal performance impact since the diffracted pupils have low intensity near the edge of the grating.
Appendix A: NIFS Linear IFU Design
System/Prescription Data
File : C:\My Documents\Peter's stuff\ZEMAX stuff\Data
Files\Nifs010c\pjm_ful_46e.zmx
Title: Gemini NIFS 0.1" slits
Date : MON DEC 20 1999
Configuration 1 of 31
LENS NOTES:
F/180 image slicer
design.
GENERAL LENS DATA:
Surfaces : 75
Stop : 2
System Aperture : Entrance Pupil Diameter = 7900
Ray aiming : Off
Apodization :Uniform, factor
= 0.00000E+000
Eff. Focal Len. :
74303.12 (in air)
Eff. Focal Len. :
74303.12 (in image space)
Back Focal Len. :
0.07651939
Total Track : 97043.49
Image Space F/# :
9.405459
Para. Wrkng F/# :
9.406295
Working F/# : 8.448871
Image Space N.A.:
0.05308566
Obj. Space N.A. :
3.949962e-007
Stop Radius : 3950
Parax. Ima. Hgt.:
0.5403908
Parax. Mag. : 0
Entr. Pup. Dia. :
7900
Entr. Pup. Pos. : 97043.49
Exit Pupil Dia. :
6.853362
Exit Pupil Pos. :
64.38249
Field Type : Angle in
degrees
Maximum Field : 0.0004167
Primary Wave : 1.65
Lens Units : Millimeters
Angular Mag. : -1152.719
Fields : 5
Field Type: Angle in degrees
# X-Value Y-Value Weight
1 0.000000
0.000000 1.000000
2 0.000000
0.000194 1.000000
3 0.000000
-0.000194 1.000000
4 0.000000 0.000417 1.000000
5 0.000000
-0.000417 1.000000
Vignetting Factors
# VDX VDY VCX VCY
1 0.000000 0.000000
0.000000 0.000000
2 0.000000 0.000000
0.000000 0.000000
3 0.000000 0.000000
0.000000 0.000000
4 0.000000 0.000000
0.000000 0.000000
5 0.000000 0.000000
0.000000 0.000000
Wavelengths : 3
Units: Microns
# Value Weight
1 1.500000
1.000000
2 1.650000
1.000000
3 1.800000 1.000000
SURFACE DATA SUMMARY:
Surf Type Comment Radius Thickness
Glass Diameter Conic
OBJ STANDARD Infinity Infinity 0 0
1 STANDARD Infinity 97043.49 7901.412 0
STO STANDARD Infinity -84504.16 7900 0
3 STANDARD TEL PRIMARY -28800 -12539.33
MIRROR 7901.233 -1.003756
4 STANDARD TEL SECONDARY -4193.068 12539.33
MIRROR 1023.221 -1.612898
5 STANDARD Infinity 3660.061 248.4108 0
6 STANDARD WINDOW Infinity 20
CAF2 180 0
7 STANDARD Infinity 231.444 180 0
8 COORDBRK - 0 -
- -
9 STANDARD SCIENCE FOLD Infinity 0
MIRROR 7.684484 0
10 COORDBRK - -94.45 -
- -
11 STANDARD TEL F PLANE Infinity -84.827 1.862834 0
12 STANDARD OPTICAL BENCH Infinity -315.173 7.109004 0
13 COORDBRK - 0 -
- -
14 STANDARD OFFNER PRIMARY 400
199.6 MIRROR 56.60869 0
15 STANDARD OFFNER SECONDARY 200.4 -199.6
MIRROR 12.39068 0
16 STANDARD OFFNER PRIMARY 400 0
MIRROR 56.56094 0
17 COORDBRK - 245.173 -
- -
18 COORDBRK - 0 - - -
19 STANDARD FOLD Infinity 0
MIRROR 16.64323 0
20 COORDBRK - -154.827 -
- -
21 STANDARD REIMAGED FOCUS Infinity -44.0894 1.862834 0
22 COORDBRK - 0 -
- -
23 STANDARD F/180 CONVERTER 80.0704 0
MIRROR 10 0
24 COORDBRK - 435.3834 -
- -
25 COORDBRK - 0
- - -
26 STANDARD SLICER BAFFLE Infinity 0 18.40271 0
27 COORDBRK - 0 - - -
28 COORDBRK - 0 -
- -
29 COORDBRK SLICER TILT - 0
- - -
30 STANDARD IMAGE SLICER -278.4111 0
MIRROR 18.3966 0
31 COORDBRK - 0 -
- -
32 COORDBRK - -213.3333
- - -
33 COORDBRK PUPIL 90 DEG ROT - 0
- - -
34 COORDBRK - 0
- - -
35 COORDBRK PUPIL DECENTER - 0
- - -
36 TOROIDAL PUPIL MIRRORS 39.5 0 MIRROR 1.50853
0
37 COORDBRK - 0 -
- -
38 COORDBRK - 21.6034 -
- -
39 COORDBRK - 0 -
- -
40 COORDBRK FIELD Y DECENTER - 0
- - -
41 COORDBRK FIELD X DECENTER - 0
- - -
42 TOROIDAL FIELD MIRRORS -43.2068 0
MIRROR 1.86345 0
43 COORDBRK -
0 - - -
44 COORDBRK - 0 -
- -
45 COORDBRK - -136.835 -
- -
46 STANDARD FIELD LENS 1 -127.1863 -20.0962
SAPPHIRE 10.36345 0
47 STANDARD -3682.418 -3 10.38093
0
48 STANDARD FIELD LENS 2 -908.7041 -10
SILICA 10.39181 0
49 STANDARD -77.7806 -76.48 10.38173 0
50 COORDBRK - 0 -
- -
51 STANDARD COLLIMATOR FOLD Infinity 0
MIRROR 14.77835 0
52 COORDBRK - 150
- - -
53 STANDARD COLLIMATOR 1 153.7321 11.094
SILICA 23.44904 0
54 STANDARD 114.4526 35.819 23.37176 0
55 STANDARD COLLIMATOR 2 -83.3029 11.2517
ZNSE 26.13534 0
56 STANDARD -97.5196 17.6441 28.61086 0
57 STANDARD COLLIMATOR 3 -3492.097 20.1007
BAF2 30.68234 0
58 STANDARD -126.9406 307.6803 32.1821 0
59 COORDBRK - 0 -
- -
60 COORDBRK - 0 -
- -
61 DGRATING GRATING Infinity 0
MIRROR 31.03555 0
62 COORDBRK - 0 -
- -
63 COORDBRK - -150
- - -
64 STANDARD CAMERA 1 -206.676 -20
CAF2 36.29981 0
65 STANDARD 234.395 -3.351 36.18648 0
66 STANDARD CAMERA 2 195.518 -10
SILICA 35.953 0
67 STANDARD 755.701 -229.674 36.03301 0
68 STANDARD CAMERA 3 -101.346 -20
CAF2 41.50165 0
69 STANDARD 216.457 -5 40.02216 0
70 STANDARD CAMERA 4 233.575 -10
ZNSE 38.98183 0
71 STANDARD 356.327 -71.254 39.16039 0
72 STANDARD CAMERA 5
92.751 -6 SAPPHIRE 31.62889
0
73 STANDARD -1094.375 -15 32.33198 0
74 STANDARD Infinity -0.075 35.16887 0
IMA STANDARD DETECTOR Infinity 35.1838 0
SURFACE DATA DETAIL:
Surface OBJ : STANDARD
Surface 1 : STANDARD
Aperture : Circular Obscuration
Minimum Radius : 0
Maximum Radius : 511
Surface STO : STANDARD
Surface 3 : STANDARD
Comment : TEL PRIMARY
Surface 4 : STANDARD
Comment : TEL SECONDARY
Aperture : Circular Aperture
Minimum Radius : 0
Maximum Radius : 511
Surface 5 : STANDARD
Surface 6 : STANDARD
Comment : WINDOW
Aperture : Circular Aperture
Minimum Radius : 0
Maximum Radius : 90
Surface 7 : STANDARD
Surface 8 : COORDBRK
Decenter X : 0
Decenter Y : 0
Tilt About X : 0
Tilt About Y : 45
Tilt About Z : 0
Order : Decenter then
tilt
Surface 9 : STANDARD
Comment : SCIENCE FOLD
Surface 10 : COORDBRK
Decenter X : 0
Decenter Y : 0
Tilt About X : 0
Tilt About Y : 45
Tilt About Z : 0
Order : Decenter then tilt
Surface 11 : STANDARD
Comment : TEL F PLANE
Surface 12 : STANDARD
Comment : OPTICAL BENCH
Surface 13 : COORDBRK
Decenter X : -25
Decenter Y : 0
Tilt About X : 0
Tilt About Y : 0
Tilt About Z : 0
Order : Decenter then tilt
Surface 14 : STANDARD
Comment : OFFNER PRIMARY
Surface 15 : STANDARD
Comment : OFFNER SECONDARY
Surface 16 : STANDARD
Comment : OFFNER PRIMARY
Surface 17 : COORDBRK
Decenter X : -25
Decenter Y : 0
Tilt About X : 0
Tilt About Y : 0
Tilt About Z : 0
Order : Decenter then tilt
Surface 18 : COORDBRK
Decenter X : 0
Decenter Y : 0
Tilt About X : 45
Tilt About Y : 0
Tilt About Z : 0
Order : Decenter then tilt
Surface 19 : STANDARD
Comment : FOLD
Surface 20 : COORDBRK
Decenter X : 0
Decenter Y : 0
Tilt About X : 45
Tilt About Y : 0
Tilt About Z : 0
Order : Decenter then tilt
Surface 21 : STANDARD
Comment : REIMAGED FOCUS
Surface 22 : COORDBRK
Decenter X : 0
Decenter Y : 0
Tilt About X : 0
Tilt About Y : -3
Tilt About Z : 0
Order : Decenter then tilt
Surface 23 : STANDARD
Comment : F/180 CONVERTER
Surface 24 : COORDBRK
Decenter X : 0
Decenter Y : 0
Tilt About X : 0
Tilt About Y : -3
Tilt About Z : 0
Order : Decenter then tilt
Surface 25 : COORDBRK
Decenter X : 0
Decenter Y :
0
Tilt About X : 0
Tilt About Y : 3
Tilt About Z : 0
Order : Decenter then tilt
Surface 26 : STANDARD
Comment : SLICER BAFFLE
Surface 27 : COORDBRK
Decenter X : 0
Decenter Y : 0
Tilt About X : 0
Tilt About Y : -3
Tilt About Z : 0
Order : Decenter then tilt
Surface 28 : COORDBRK
Decenter X : 0
Decenter Y : 0
Tilt About X : 0
Tilt About Y : 3
Tilt About Z : 0
Order : Decenter then tilt
Surface 29 : COORDBRK
Comment : SLICER TILT
Decenter X : 0
Decenter Y : 0
Tilt About X : 0
Tilt About Y : 0
Tilt About Z : 0
Order : Decenter then tilt
Surface 30 : STANDARD
Comment : IMAGE SLICER
Aperture : Rectangular Aperture
X Half Width :
0.3447
Y Half Width : 12
Surface 31 : COORDBRK
Decenter X : 0
Decenter Y : 0
Tilt About X : 0
Tilt About Y :
0
Tilt About Z : 0
Order : Decenter then tilt
Surface 32 : COORDBRK
Decenter X : 0
Decenter Y : 0
Tilt About X : 0
Tilt About Y : 3
Tilt About Z : 0
Order : Decenter then tilt
Surface 33 : COORDBRK
Comment : PUPIL 90 DEG ROT
Decenter X : 0
Decenter Y : 0
Tilt About X : 0
Tilt About Y :
0
Tilt About Z : 90
Order : Decenter then tilt
Surface 34 : COORDBRK
Decenter X : 0
Decenter Y : 0
Tilt About X : -6
Tilt About Y : 0
Tilt About Z : 0
Order : Decenter then tilt
Surface 35 : COORDBRK
Comment : PUPIL DECENTER
Decenter X : 0
Decenter Y : 0
Tilt About X : 0
Tilt About Y :
0
Tilt About Z : 0
Order : Decenter then tilt
Surface 36 : TOROIDAL
Comment : PUPIL MIRRORS
Rad of rev. : 38.9
Coeff on y^2 : 0
Coeff on y^4 : 0
Coeff on y^6 : 0
Coeff on y^8 : 0
Coeff on y^10 : 0
Coeff on y^12 : 0
Coeff on y^14 : 0
Aperture : Rectangular Aperture
X Half Width :
1.0239
Y Half Width : 2.5
Surface 37 : COORDBRK
Decenter X : 0
Decenter Y : 0
Tilt About X : 0
Tilt About Y : 0
Tilt About Z : 0
Order : Decenter then tilt
Surface 38 : COORDBRK
Decenter X : 0
Decenter Y : 0
Tilt About X : -6
Tilt About Y : 0
Tilt About Z : 0
Order : Decenter then tilt
Surface 39 : COORDBRK
Decenter X : 0
Decenter Y : 0
Tilt About X : 6
Tilt About Y : 0
Tilt About Z : 0
Order : Decenter then tilt
Surface 40 : COORDBRK
Comment : FIELD Y DECENTER
Decenter X : 0
Decenter Y : 0
Tilt About X : 0
Tilt About Y : 0
Tilt About Z : 0
Order : Decenter then tilt
Surface 41 : COORDBRK
Comment : FIELD X DECENTER
Decenter X : 0
Decenter Y : 0
Tilt About X : 0
Tilt About Y : 0
Tilt About Z : 0
Order : Decenter then tilt
Surface 42 : TOROIDAL
Comment : FIELD MIRRORS
Rad of rev. : -39.5
Coeff on y^2 : 0
Coeff on y^4 : 0
Coeff on y^6 : 0
Coeff on y^8 : 0
Coeff on y^10 :
0
Coeff on y^12 : 0
Coeff on y^14 : 0
Aperture : Rectangular Aperture
X Half Width :
1.029
Y Half Width :
2.5
Surface 43 : COORDBRK
Decenter X : 0
Decenter Y : 0
Tilt About X : 0
Tilt About Y : 0
Tilt About Z : 0
Order : Decenter then tilt
Surface 44 : COORDBRK
Decenter X : 0
Decenter Y :
0
Tilt About X : 0
Tilt About Y : 0
Tilt About Z : 0
Order : Decenter then tilt
Surface 45 : COORDBRK
Decenter X : 0
Decenter Y : 0
Tilt About X : 6
Tilt About Y : 0
Tilt About Z : 0
Order : Decenter then tilt
Surface 46 : STANDARD
Comment : FIELD LENS 1
Surface 47 : STANDARD
Surface 48 : STANDARD
Comment : FIELD LENS 2
Surface 49 : STANDARD
Surface 50 : COORDBRK
Decenter X : 0
Decenter Y : 0
Tilt About X : -15
Tilt About Y : 0
Tilt About Z : 0
Order : Decenter then tilt
Surface 51 : STANDARD
Comment : COLLIMATOR FOLD
Aperture : Rectangular Aperture
X Half Width : 45
Y Half Width : 15
Surface 52 : COORDBRK
Decenter X : 0
Decenter Y : 0
Tilt About X : -15
Tilt About Y : 0
Tilt About Z : 0
Order : Decenter then tilt
Surface 53 : STANDARD
Comment : COLLIMATOR 1
Surface 54 : STANDARD
Surface 55 : STANDARD
Comment : COLLIMATOR 2
Surface 56 : STANDARD
Surface 57 : STANDARD
Comment : COLLIMATOR 3
Surface 58 : STANDARD
Surface 59 : COORDBRK