ins nirspec, 12 may 2005 introduction to nirspec michael regan
TRANSCRIPT
![Page 1: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/1.jpg)
INS NIRSpec, 12 May 2005
Introduction to NIRSpec
Michael Regan
![Page 2: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/2.jpg)
JWST Project OrganigrammeJune 2004
JWSTProject Manager
P. Jensen
NIRSpec Pr. System Engineer
G. Bagnasco
Launcher System EngineerP. Rumler
System Group
MIRI Principal System Engineer
A. Marini
Admin. AssistantA. Plitzke
Documentation & Conf. Control
D. Green
Mech. Thermal System Engineer
J-C. Salvignol
Project Control Manager
Z. El Hamel
PA ManagerJ. van Dooren
Subsystem Expert Group
Optical System Engineer
M. Te Plate
Electr. System Engineer & AIV
P. Rumler
Ops, SW & Detector System
P. Strada
Mechanism Engineer*B. Henson * leaving
Schedule ControlJ. Molleman
Project ScientistP. Jakobsen
Deputy Project ScientistT. Boeker
Science Operations Team
NN
Science SupportNN
Contracts OfficerV. D’Hoedt
Optical SupportP. Marenaci (YGT)
![Page 3: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/3.jpg)
INS NIRSpec, 12 May 2005
JWST Architecture
Optical Telescope
Element (OTE)
Integrated Science Instrument
Module (ISIM) Element
Spacecraft Bus
Sunshield
Sun
![Page 4: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/4.jpg)
INS NIRSpec, 12 May 2005
Telescope
![Page 5: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/5.jpg)
INS NIRSpec, 12 May 2005
Telescope
FocalSurface
Prim
ary
M
irro
r
Secondary Mirror
Fine Steering
Mirror
Te
rtia
ry
Mirr
or
OTE ISIM
Secondary focus
(V1, V3) origin
V3
V1 V2
OTEf/#: 16.7Effective Focal Length: 116.6 mPM diameter = 7.0 m
FocalSurface
Prim
ary
M
irro
r
Secondary Mirror
Fine Steering
Mirror
Te
rtia
ry
Mirr
or
OTE ISIM
Secondary focus
(V1, V3) origin
V3
V1 V2
OTEf/#: 16.7Effective Focal Length: 116.6 mPM diameter = 7.0 m
![Page 6: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/6.jpg)
INS NIRSpec, 12 May 2005
ISIM & Regions
![Page 7: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/7.jpg)
INS NIRSpec, 12 May 2005
Thus Spoke ASWG
![Page 8: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/8.jpg)
INS NIRSpec, 12 May 2005
Current Mission Requirements
(the TAC will decide anyway…)
![Page 9: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/9.jpg)
INS NIRSpec, 12 May 2005
NIRSpec
![Page 10: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/10.jpg)
INS NIRSpec, 12 May 2005
NIRSpec: A Pretty Picture is Not Enough
Enter NIRSpec
![Page 11: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/11.jpg)
INS NIRSpec, 12 May 2005
NIRSpec: Thus Spoke ASWG
• 3 x 3 arcmin FOV
• 1-5 µm coverage
• R~1000, R~100 multiplexed
• >100 sources simultaneously
• Configurable slit width/length
• MEMS array preferred
![Page 12: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/12.jpg)
INS NIRSpec, 12 May 2005
NIRSpec Procurement
• Instrument built by European industry
under ESA project leadership
• Under study since 2001
• Presently entering implementation phase
• Two NASA-provided components:• 2 x 2k x 2k HgCdTe Detector Array• 4 x 384 x 185 Micro-Shutter Array
![Page 13: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/13.jpg)
INS NIRSpec, 12 May 2005
NIRSpec Modes
• R=100 (exploratory spectroscopy)• Single prism 0.6 - 5.0 µm
• Micro-shutter array or fixed Slits
• R=1000 (emission line diagnostics)• 3 gratings 1.0 - 5.0 µm
• Micro-shutter array or fixed slit(s)
• R=3000 (emission line kinematics)• 3 gratings 1.0 - 5.0 µm
• Fixed slit or integral field unit
![Page 14: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/14.jpg)
INS NIRSpec, 12 May 2005
Wavelength Coverage
• R=1000 & R=3000 modes• 1.0 - 5.0 µm• Covered by three overlapping first order gratings:
• 1.0 - 1.8 µm• 1.7 - 3.0 µm• 2.9 - 5.0 µm
• R=100 mode• 0.6 - 5.0 µm (as NIRCAM)• Covered by single dual-pass prism• Coverage below 1.0 µm is not allowed to drive anything
• Resolution to be kept within factor 2 of R=100 1.0 - 5.0 µm• Resolution below 1.0 µm to follow
![Page 15: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/15.jpg)
INS NIRSpec, 12 May 2005
You Can’t Fight Red shift
!
NIR MIR
!
![Page 16: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/16.jpg)
INS NIRSpec, 12 May 2005
Micro Shutter Array
Active MSA Area
3.6’
3.4’
Mounting Frame
Detector Array
Fixed Slits and
IFU Aperture
Direction of Dispersion
4 x 384 x 185 Shutters 9 Square Arcmin of MSA
Area
Single 200 mas x 450 mas slitssurrounded by 60 mas wide bars
>100 objects simultaneously
IFU
![Page 17: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/17.jpg)
INS NIRSpec, 12 May 2005
A Bit of MEMS History
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
• Initially both Micro Mirrors and Shutters
• Mirrors eliminated due to excessive diffraction effects
• Initially slit to be made up of several shutters
• Later transitioned to “fat MEMS”• Huge simplification of optics• Factor ~4 reduction in MSA array• Reduced slit loss • At expense of multiplexing loss
![Page 18: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/18.jpg)
INS NIRSpec, 12 May 2005
Diffraction & Slit Loss
Telescope Exit Pupil
Spectrograph Entrance Pupil
Footprint of PSF
Diffracted OutputBeam
![Page 19: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/19.jpg)
INS NIRSpec, 12 May 2005
MSA Close-up
Key Requirements:Contrast: >2000 (!) Open Fill factor >70%(60 mas bars on 200 mas wide slits)
![Page 20: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/20.jpg)
INS NIRSpec, 12 May 2005
MSA Magnet Mechanism
![Page 21: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/21.jpg)
INS NIRSpec, 12 May 2005
MSA in Action
![Page 22: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/22.jpg)
INS NIRSpec, 12 May 2005
Integral Field Unit
Field beforeslicing
Pseudo-slit
Slicing mirror (S1)
Spectrogram
Pupil mirrors(S2)
To spectrograph
Field optics (slit mirrors S3)
From telescopeand fore-optics
![Page 23: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/23.jpg)
INS NIRSpec, 12 May 2005
Integral Field Unit
• FOV: 3” x 3”• Sampling: 0.1”• ~30 Slicers
• Entirely passive device (no moving parts)
• Shuttered by MSA magnet mechanism
• Main use R~3000 single object• But R~1000 and R~100 too....
• Superb backup in case of MSA failure• Point and shoot operations
![Page 24: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/24.jpg)
INS NIRSpec, 12 May 2005
Integral Field Unit
Slicer Stack(30 slices)
IFU aperturePupil mirror Line(30 elements)
Slit mirror Line(30 elements)
Relay optics
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
![Page 25: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/25.jpg)
INS NIRSpec, 12 May 2005
Detector Array• 2K4K FPA comprised of two 2K2K
sensor chip assemblies (SCAs)
• =0.6–5.0 µm HgCdTe detectors (Rockwell)
• FPA passively cooled to T=34–37 K
• Key Performance Parameters:• Total noise =6 electrons rms per t=1000 seconds exposure)• QE = >80%
• NIRSpec is detector background limited in nearly all
modes (!)
• Non-stop (“up the ramp”) read and telemetry• 12 s frame time, 1 frame downlink each 50 s
![Page 26: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/26.jpg)
INS NIRSpec, 12 May 2005
Why R=1000?
![Page 27: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/27.jpg)
INS NIRSpec, 12 May 2005
Why R=1000?
• Science requirement• Clean emission line separation
• Main challenge:• [NII] 6548.1 :1• H 6562.8 metallicity diagnostic• [NII] 6583.4 :3
• and also:• [SII] 6716.4 density diagnostic• [SII] 6730.8
R=446
R=319
R=467
[NII]
H
[NII]
![Page 28: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/28.jpg)
INS NIRSpec, 12 May 2005
Why 200 mas Slit?
1:2 MSA aspect ratio fixed
1.4 µm - Band I2.4 µm - Band II4.0 µm - Band III
![Page 29: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/29.jpg)
INS NIRSpec, 12 May 2005
Why 200 mas Slit?
200 mas optimal?
2 pixels across slit
![Page 30: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/30.jpg)
INS NIRSpec, 12 May 2005
Optical Schematic
MIcro-shutterArray Collimator
Prism/Grating CameraDetector
Array
Telescope Focus
Foreoptics FilterWheel
200 mas per 79.5 µm wide shutter
2.52 “/mm, f/12.5
100 mas per 18 µm pixel
5.56 “/mm, f/5.671.58 “/mm, f/20
![Page 31: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/31.jpg)
INS NIRSpec, 12 May 2005
Optical Layout
Buzzwords: • TMA’s• Scheimflug
![Page 32: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/32.jpg)
INS NIRSpec, 12 May 2005
Focal Plane Layout & Scheimflug
NIRCam NIRSpec
![Page 33: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/33.jpg)
INS NIRSpec, 12 May 2005
Physical Layout
![Page 34: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/34.jpg)
INS NIRSpec, 12 May 2005
Physical Layout
![Page 35: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/35.jpg)
INS NIRSpec, 12 May 2005
SiCThe wonder of modern ceramics
![Page 36: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/36.jpg)
INS NIRSpec, 12 May 2005
WFE at MSA
• Requirement:• Diffraction-limited at 2.4 µm• WFE = 180 nm rms or better• 131 nm rms OTE input specified
• Fore optics challenging
• Relaxation requires degrading sensitivity• Increased slit losses• Reduced photometric accuracy
![Page 37: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/37.jpg)
INS NIRSpec, 12 May 2005
WFE at FPA
• Requirement:• Diffraction-limited at 3.0 µm• WFE = 225 nm rms or better
• Camera optics challenging• Relaxation requires degrading
sensitivity• Larger resolution element• Decreased sensitivity• Jeopardize spectral resolution [NII]
H
[NII]
![Page 38: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/38.jpg)
INS NIRSpec, 12 May 2005
NIRSpec Image Quality
PSF at MSA
PSF at FPA
FPA 100 mas pixels
PSF at MSA
FPA with Cross-talk
![Page 39: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/39.jpg)
INS NIRSpec, 12 May 2005
Grating Wheel8 Positions:
1. R=100 Prism 2. Band I R=1000 Grating 3. Band II R=1000 Grating 4. Band III R=1000 Grating 5. Band I R=3000 Grating 6. Band II R=3000 Grating 7. Band III R=3000 Grating 8. Provision for imaging mode
![Page 40: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/40.jpg)
INS NIRSpec, 12 May 2005
Filter Wheel
8 Positions:
1. Clear Aperture 2. Closed 3. Band I Long Pass >1.0 µm4. Band II Long Pass >1.7 µm5. Band III Long Pass >2.9 µm6. Narrow Band TA =1.1 µm7. Broad Band TA 0.9 < 1.1 µm8. Broad Prism 0.9 < 5 µm
Current Issue: Filters in pupil – should they second as pupil stops?
![Page 41: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/41.jpg)
INS NIRSpec, 12 May 2005
Why Long Pass?One Object per Row
![Page 42: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/42.jpg)
INS NIRSpec, 12 May 2005
Calibration Unit
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Carries both continuum and (FP-filtered) line sources
![Page 43: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/43.jpg)
INS NIRSpec, 12 May 2005
NIRSpec Sensitivity
Formal Level I Specs
![Page 44: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/44.jpg)
INS NIRSpec, 12 May 2005
Mission Requirements
![Page 45: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/45.jpg)
INS NIRSpec, 12 May 2005
Mission Requirements
![Page 46: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/46.jpg)
INS NIRSpec, 12 May 2005
Target Acquisition
Partially documented in gory detail… • NIRSpec Operations Concept• Two dedicated tech notes (more to come)
Accuracy Goal: 12.5 mas (1)
![Page 47: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/47.jpg)
INS NIRSpec, 12 May 2005
Image Mode Simulation
2.2 µm
Centroid shift!
![Page 48: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/48.jpg)
INS NIRSpec, 12 May 2005
Target Acquisition will be interesting
![Page 49: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/49.jpg)
INS NIRSpec, 12 May 2005
STScI is currently working on several NIRSpec related studies
• MSA planning tool (J. Valenti)• NIRSpec Target Acquisition Alternatives
(M. Regan)• What’s in phase 1 and phase 2 with
JWST (J. Valenti)
![Page 50: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/50.jpg)
INS NIRSpec, 12 May 2005
STScI plays a crucial role in NIRSpec
• MSA planning tool (J. Valenti)• NIRSpec Target Acquisition Alternatives (M.
Regan)• What’s in phase 1 and phase 2 with JWST (J.
Valenti)• NIRSpec Calibration Plan ( T. Keyes)• Guide Star Availability and planning (J. Valenti)• Do we use Observing templates? (J. Valenti)
![Page 51: INS NIRSpec, 12 May 2005 Introduction to NIRSpec Michael Regan](https://reader036.vdocuments.net/reader036/viewer/2022062517/56649f055503460f94c19c70/html5/thumbnails/51.jpg)
INS NIRSpec, 12 May 2005