Transcript 幻灯片 1 - INAF - Osservatorio Astrofisico di Catania

A Proposal of
Long Slit Spectrograph
for WSO/UV
Zhongwen Hu
Nanjing Institute of Astronomical Optics and Technology,
National Astronomical Observatory of China, CAS
National WSO/UV Implementation Committee of China
2006-June-28
Contents
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Team Members Introduction
Requirements and assumption
layout overview of NIAOT LSS
Configurations and performance of LSS
Cooperation Expected
Quotation results of diffraction Gratings
Cross check results of the optics design
Schedule
NIAOT Introduction
• A unique research base in China, specialized in
professional astronomical telescopes and instruments
– 50 astronomical telescopes and instruments ;
30 exported to the USA, Spain, Japan and South
Korea.
• Four main Laboratory
– Mirror Technology
– Astronomical Spectrum and High Resolution Imaging
– Solar Instruments
– New Technology Telescope
Team members introduction
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Prof. Yongtian Zhu,
Dr. Zhongwen Hu,
Dr. Yi Chen,
Ms. Jianing Wang,
Mr. Lei Wang,
director
Optics
FEA
Electronics
Precision mechanics
Prof. Yongtian Zhu
• Vice Director of NIAOT
• Experience
– the Coude Echelle Spectrograph for Chinese
2.16-meter astronomical Telescope
– Spectrographs for LAMOST project
– Proposed a novel two-mirror system for the
soft X-ray projection lithograph
Dr. Zhongwen Hu
• Soft X-ray beamline construction and calibration of a
varied angle spherical grating monochromator
(12-120nm)
• Echelle spectrograph (200-500nm)
• Polychromator ( 31channels) (UV-Visible).
• High precision measurements of grating groove density for
VLS concave diffraction gratings (Uncertainty 1x10-5).
Especially small curvature radius gratings.
• Expression of groove density (N) and groove function (n)
applicable for any gratings
Soft x-ray beamline optics
First gas absorption spectrum
with resolution 1000
 Movements in super high vaccum
3 Gratings could be exchanged
Gratings rotated to scan wavelength
Mirror rotated to compensate defocus
NIAOT contribution to LSS
• Under direction of WIC working group of China
• NIAOT responsibilities
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Participate system requirement definition
Design of LSS
Construction of prototype, flight model and test system
Complete instrument level test in China
• Some crosscheck of LSS test in Ukraine ?
– Participate Integration with rest of WSO
– Develop Calibration and data reduction methodology
LSS References
• THE ROWLAND MULTICHANNEL LONG SLIT
SPECTROGRAPH FOR THE WSO/UV MISSION
----- R.E. Gershberg ,et.al
• HIRDES Phase A Study
-----Dr. Schwarz & Project Team
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Performance of the Long-Slit Spectrograph (LSS)
----V. Terebizh
New designs of LSS
Possible layouts with various resolution-
wavelength pattern
Optimized space and spectrum resolution with
extended wavelength coverage
 Expect better image quality for every point on
slit
Use of special gratings
 Diffraction grating types
Classical gratings
VLS concave gratings
Holographic gratings of
the first generation
Holographic gratings of
the second generation
How to determine
requirements of the LSS
?
Interactive procedure between science mission
requirements and technology capability and
availability
Distance of slit from optical axis
Entrance： Width of slit
Length of slit
Coating of surfaces
10  49.5 mm
Rectangular: 1  82 m
75  6.2 mm
Al + MgF2
Far Ultraviolet (FUV)
Near Ultraviolet (NUV)
1150  1775 Å
1750  3000 Å
Refl. at 1150 Å； 1, /3 surfaces
at 1216 Å； 1 , /3 surfaces
at 3000 Å； 1 , /3 surfaces
60 %, / 21 %
82 %, / 55 %
87 %, / 66 %
LSS optical layout：
Dispersive element
Curvature radii
Light diameter
Approximate size
Requirements
baseline of current
NIAOT design
Modified Rowland-circle
spectrograph with one reflection
Concave grating
R1 and R2 ~ 1 m
110 mm
Performance of the LongSlit Spectrograph
(LSS)
1050 mm  350 mm
Spectral resolution  : FUV
NUV
2000  3000
1500  3000
Preliminary results
Spectral resolution  for stars
~ 5000
V. Terebizh, April 2005
Space resolution
0.40”
Number of detectors
24
Optical configuration of LSS and Position
589
313
Unit of LSS mounting to the Optical Bench
60
Spectrometer case LSS
120
52.
7
450
462
LSS
UV Spectrometer
VUV Spectrometer
Modified Rowland
configuration
+Z
LSS position in the
instrument bay
+Y
A layout by R.E. Gershberg et.al
(3 detectors and 6 gratings)
Overview of our layout
Three possible layouts are considered:
Layout 1a, Layout 1b, layout2
Each layout is shown with its resolutionwavelength pattern
3 layouts of NIAOT design
Layout 1a
Resolution
Detector 1
500
1450
Wavelength
range(Å)
1100-3500 1150-1655
Layout 1b
Detector 1
Resolution
500
Detector 2
5000
5800
5800
2000-2370
2360-2710
2700 -3100
Detector 2
1450
2500
2000
1150-1775
1750-3050
Wavelength
range(Å)
1100-3500 1150-1655
Layout 2
Detector 1
Resolution
500
2500
2000
5000
5800
5800
Wavelength
range(Å)
11003500
11501775
17503050
20002370
23602710
2700 3100
Detector 2
Detector 3
Resolution-Wavelength pattern
Layout 1a(5 gratings, 2 detctors)
Two gratings cover 2360-3100
6000
2000-2370
5000
Resolution
4000
3000
2000
1150-1655
1000
Very good image across 1100-3500
0
1000
1500
2000
2500
Wavelength
3000
3500
Resolution-Wavelength pattern
Layout 1b(4 gratings, 2 detctors)
3000
1150-1775
One grating cover 1750-3050
Resolution
2000
1150-1655
1000
Very good image across 1100-3500
0
1000
1500
2000
2500
Wavelength
3000
3500
Resolution-Wavelength pattern
Layout 2(6 gratings, 3 detctors)
Two gratings cover 2360-3100
6000
2000-2370
5000
Resolution
4000
3000
1150-1775
One grating cover 1750-3050
2000
1000
Very good image across 1100-3500
0
1000
1500
2000
2500
Wavelength
3000
3500
R.E. Gershberg’s proposal
with 3 detectors and 6 gratings
6000
5500
5000
4500
Resolution
4000
1385-1575
1788-2032
3500
3000
2500
2000
3 gratings cover 1200-3500
1500
1000
Image quality merely acceptable 1200-3400
500
0
1000
1500
2000
2500
Wavelength
3000
3500
Layout 1a
(2 detectors and 5 gratings)
Grating
Detector
Configurations and performance
 Optical parameters
 Image quality
 Resolution achieved
Layout parameters for detector 1.
R=500
Detector size (mm^2)
Pixel size
(um^2)
42.1x6.5
25x12
Grating No.
1( Resolution 500)
10( Resolution 1450)
Wavelength range(Å)
1100 ~3500
1150-1655
Incident Angle(deg)
4.176
6.625
Diffraction Angle(deg)
-1.6363
0.814
Detector 1
Detector Tilt(deg)
3.39
Incident Length(mm)
897.737
Detector Position(mm)
895.0517
Detector Radius
Infinite
Spot diagram on detector 1 with grating 1. Left is the images for different
points on 6.2 mm slit within the related wavelength. Right is RMS spot
radius which shows good space and spectrum resolution for varied slit
positions.
Resolution test
Slit width is 82 microns along spectrum direction
 space resolution 32 microns along the entrance slit.
 Gaussian distribution of image on slit with FWHM
equals the slit width is assumed.
Layout parameters for detector 2
(1150 Å ~ 3050 Å, two gratings). R=2500
Detector size (mm^2)
Pixel size(um^2)
93.5 x6.5
25x12
Grating No.
2 (Resolution 2500)
3 (Resolution 2000)
Wavelength range(Å)
1150~1775
1750~3050
Incident Angle(deg)
12
10.725
Diffraction Angle(deg)
0.1253
-1.1456
Detector 2 (alternative)
Detector Tilt(deg)
8.3755
Incident Length(mm)
1035
Detector Position(mm)
1022
Detector Radius(mm)
1037.832
Layout parameters for detector 3
(2000 Å ~ 3500 Å, three gratings). R=5000
Detector size
(mm^2)
Pixel size
(um^2)
76 x6.5
25x16
Grating No.
4
(R= 5000)
5
(R= 5800)
6
(R= 5800)
Wavelength range(Å)
2000~2370
2360~2710
2700 ~3100
Incident Angle(deg)
21.486
22.982
23
Diffraction Angle(deg)
8.532
10.0267
10.0445
Detector 3
Detector Tilt(deg)
0
Incident Length(mm)
1035
Detector
Position(mm)
953.471
Detector Radius(mm)
902.776
Mechanical interface problem
LSS
UV Spectrometer
VUV Spectrometer
+Z
1.Gratings enter into spaces of
UV and VUV chamber
--- Space resolution and detector
pixel dimension
+Y
2.How many detectors
mechanically available
---with or without folding
mirrors?
---Interference with FC ?
International cooperation expected
• Detectors
– The detector unit (with the High Voltage
system) could be supplied by Britain?
• Electronics
– Digital process unit provided by Germany?
• other
Detectors available?
– Curved surface
detector surface could be a flat plane
– Rectangular pixel
Square pixel
degraded space resolution,
two point sampling
– Maximum available pixels
– Mechanical dimensions
Possible vendors of gratings
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Jobin Yvon (France),
Spectra-physics (U.S.),
Carl Zeiss(Germany),
Shimadzu(Japan),
Bruno Touzet
Doug Buerkle
Klaus Heidemann
Shinn Takada
Grating has a diameter 115mm.
Gratings could be one of the following type.
a. spherical gratings fabrcated by aspheric
optics
b. asperical grating available
Grating parameters
(Recording wavelength 310nm.)
3
4
5
1026.626
987.6782
982.812
895.917 1001.634
1005.007
990.4428
994.145
Y of P1
53.4717
-217.144
-131.237
178.386
294.7175
Z of P1
897.115
-976.88
-1022.002
-692.005
-1043.679
Y of P2
0.1468
244.804
92.791
2974.360
5
2755.836
Z of P2
-1060.278
-1042.999
895.451
607.54
-780.765
Grating No.
Tangential
Radii
Sagital Radii
1
2
900
1023.278
6
982.336
994.602
387.576
-1043.92
2577.349
-827.065
Gratings, Reply from Jobin Yvon
(France),
– They can make our gratings on a custom substrate
• difficult for them to fabricate the toroidal substrate
close to a sphere
– They made their own calculations use the same layout
parameters with modified recording wavelength
Comparison
(110nm~350nm resolution 500)
---by Jobin Yvon
NIAOT
310nm recording wavelength
Jobin Yvon
with a different wavelength
Grating 1 (resolution 500)
Grating 10 (resolution 1450)
Summary of NIAOT design (1)
The incident, the diffracted angles and the positions of
detectors could be tuned to meet the space mechanically
available for LSS
Very good image quality with extended wavelength range
or increased resolution through points along the entrance slit.
Show the possibility to integrates some merits of several
previous designs.
Summary of NIAOT design (2)
For resolution 500 on detector 1
Very good image quality is obtained across wavelength
interval 1100 Å ~ 3500 Å through points on the slit.
No auxiliary reflecting mirror needed in principle.
─It depends on mechanical space available for LSS
Summary of NIAOT design (3)
For resolution ~2500, detector 2
the wavelength range is covered by two gratings like Willem
Wamsteker’s proposal,
yet it has the image quality similar to that described in R.E.
Gershberg’s four gratings mode or double gratings mode with
resolution 1500.
resolution ~5000 on detector 3
Notes
• Optical designs show improvements of the
LSS performance.
• Yet it is not the finalized form considering
the uncertainties in detectors and science
mission requirements.
• System requirements concerning
wavelength intervals and their resolution
should be to optimized and balanced for
newly claimed scientific mission
Schedule
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2006.02-2007.03: Phase 0+A: Functional Requirements.
Feasibility study. Initialization of procurement of component.
2006.12-2007.11: Phase B: Requirement specifications,
Engineering environment set-up and preliminary design.
2007.11-2008.09: Phase C: Detailed design.
2008.09~2009.09: Phase D: Production of Flight Model.
Ground qualification testing.
2009.09~2010.03: Assembling, Integration, and Verification,
with the spacecraft.
2010.03~2010.09: Pre-launch testing
2010.10: Launch
Thank you !