1. KU Leuven MIRI team meeting
MIRI in a nutshell
Bart Vandenbussche
KU Leuven MIRI team meeting
Leuven, 20 june 2013 1

2. 2

3. JWST elements 3 Optical Telescope Element (OTE)
Integrated Science Instrument Module (ISIM)
Located inside an OTE provided ISIM Enclosure
Contains 4 Science Instruments (NIRCam, NIRSpec
MIRI, FGS / TF)
ISIM Electronics
Compartment (IEC)
Optical Telescope Element (OTE)
6 meter Tri-Mirror Anastigmatic
18 Segment Primary Mirror
OTE Backplane
/ ISIM Enclosure
OTE Deployment
Tower
OTE Secondary
Mirror
OTE Primary Mirror
Aft Optics
Subsystem
Thermal Region 2
Components maintained at
ambient temperatures on cold
side of the observatory
Thermal Region 1
Components cooled to
cryogenic temperatures
Thermal Region 3
- Components maintained
at ambient temperatures
Sunshield (SS)
5 layers to provide thermal
shielding to allow OTE and ISIM
to passively cool to required
cryogenic temperatures
SS Layer 5
SS Layer 1
Momentum
Trim-Tab
Spacecraft Bus
Contains traditional
“ambient” subsystems
Solar Array 3

4. STOWED / DEPLOYED configuration
6.100 m
Deployed Configuration
6.600 m m m
Stowed Configuration m 4
4.472 m

5. JWST in the Ariane 5 fairingD
XLV 5

6. JWST space and ground segment
L2 Point
L2 Lissajous
Orbit
One 4 Hour Contact with the Ground Every 12 Hours
Ka-Band Science Link ( Selectable 7, 14, 28 Mbps)
S-Band Tlm Link (Selectable Kbps)
S-Band Cmd (Selectable 2 and 16 Kbps)
S-Band Ranging
S-Band Tlm Link ( 2Kbps)
S-Band Cmd Link (0.25 Kbps)
S-Band Ranging
Observatory – Upper Stage
Separation
Observatory Deployments
Solar Array
High Gain/ Medium Antennas
Sunshield
Optical Telescope Element
Communications Coverage Provided
For all Critical Events
L2 Transfer
Trajectory
Ariane 5 Upper
Stage Injects JWST
Into Direct Transfer
S-Band Tlm Link ( 2Kbps)
S-Band Ranging
Deep Space Network
Space Telescope Science Institute
Science & Operations Center
GSFC Flight Dynamics Facility
Ariane 5
Launch
System
NASA Integrated Services Network
Ariane PPF S5
Communications
Services for Launch
(TDRS, ESA, …)
Observatory /
LV Clocking
Angle 6

7. Integrated Science Instruments Module ISIM7

8. JWST Thermal OTE “BIB” OTE “Frill” Backplane Support Frame (BSF)
Cryogenic Radiators
MIRI Radiative Shield
Sunshield Membrane
Management Subsystem
Observatory Core Area
ISIM Electronics Compartment (IEC)
Sunshield Close-Out
Deployed Tower Assembly
MIRI Cryo-Cooler Refrigerant Deployed
Line Assembly (RLDA) 8

9. MIRI subsystems 9

10. 10

11. 11

12. JWST instruments 12

13. MIRI 13

14. MIRI overview 14

15. MIRI Imager MIRIM focal plane layout15

16. Focal Plane Mask, Debris Disk
MIRIM filters
Filter name
λ(μm)
Δλ(μm)
Comment
F560W
5.6
1.2
Broad Band
F770W
7.7
2.2
F1000W 10 2
Silicate, Broad Band
F1130W
11.3
0.7
PAH, Broad Band
F1280W
12.8
2.4
F1500W 15 3
F1800W 18
F2100W 21 5
F2550W
25.5 4
F2550WR
Redundant Filter
FND
Neutral Density
For Coron. Acquis.
F1065C
10.65
0.53
Phase mask, NH3, silicate
F1140C
11.4
0.57
Phase mask, cont. or PAH
F1550C
15.5
0.78
Phase mask, cont.
F2300C 23
4.6
Focal Plane Mask, Debris Disk
OPAQUE
Blackened Blank
N/A
For Darks 16

17. Coronograph 17

18. Imager filter wheel 18

19. Low resolution spectrograph19

20. MIRIM summary 20

21. Calibration sources
Injected through hole in pupil plane image Hot filament, non-imaging flux concentrator. One for MIRIM, one for MRS 21

22. Medium Resolution Spectrometer - MRS22

23. Spectrometer pre-optics
LT: light trap
BF: blocking filter
Dichroics on 2 dichroic wheel assemblies
Wheel 1: 1a / 1b / 1c
Wheel 2+3: 2a+3a / 2b+3b / 2c+3c

24. MRS dichroic filtering scheme
System transmissions:
S[1a] = (1 - t[1a]) * t[blocking1]
S[1b] = (1 - t[1b]) * t[blocking1]
S[1c] = (1 - t[1c]) * t[blocking1]
S[2a] = t[1a] * (1 - t[2a]) * t[blocking2]
S[2b] = t[1b] * (1 - t[2b]) * t[blocking2]
S[2c] = t[1c] * (1 - t[2c]) * t[blocking2]
S[3a] = t[1a] * t[2a] * (1 - t[3a])
S[3b] = t[1b] * t[2b] * (1 - t[3b])
S[3c] = t[1c] * t[2c] * (1 - t[3c])
S[4a] = t[1a] * t[2a] * t[3a])
S[4b] = t[1b] * t[2b] * t[3b])
S[4c] = t[1c] * t[2c] * t[3c])

25. System transmissions from component dichroic transmission fts measurements

26. MRS channels 26

27. MRS Anamorphic pre-optics + IFU27

28. Anamorphic pre-optics (APO)
assymetric magnification square input field to rectangular image on slicer 28

29. IFU 29

30. Spectrometer main optics30

31. Gratings are on the same wheels as dichroics31

32. MRS IFU 32

33. MRS focal plane arrays 33

34. D2c calibration file: camera (x,y) to (lambda, s/c
MRS cube reconstruction
D2c calibration file: camera (x,y) to (lambda, s/c 34

35. MRS field and spatial resolution
Channel
Wavelength
Pixel Size
Slice Width
Slices
FOV
Resolving Power µm
arcsec #
arcsec2 1
0.196
0.176 22
3.00 x 3.87 2
0.277 16
3.50 x 4.42 3
0.245
0.387
5.20 x 6.19 4
0.273
0.645 12
6.70 x 7.73

36. MRS summary 36

37. Raytheon Si:As 1024x1024 BIB detectors SB305 ROIC
Detectors: Focal Plane Module (FPM)
Raytheon Si:As
1024x1024
BIB detectors
SB305 ROIC 37

38. INTEGRATION RAMPS 2.7 or 27 secnds (fast/slow mode) (for full frame)38

39. Subarrays
Time between two frames
depends on size subarray 39

40. REFERENCE PIXELS 40

41. REFERENCE OUTPUT 41

42. LVL1 VERSUS LVL2
LVL 1
LVL2 42

43. LVL2 STRUCTURE 43

44. LVL2 EXTENSIONS 44