Spectrograph Design Study KickOff 17 December 2012 Reference
Spectrograph Design Study Kick-Off 17 December 2012
Reference Materials Provided for Design Study • Big. BOSS-doc-148 v 1. pdf: Specification listing the requirements on the spectrograph and describing the auxiliary equipment associated with it. • BB_SPEC_20121213. ZAR: Zemax file of Berkeley’s best spectrograph optical design. • FTS Lab Volume. pdf: Drawing showing details of the room in which the ten spectrographs will be installed on the mountain. 2
Some Notable Changes from Draft Spec to version 1 of Big. BOSS-doc-148 • Removed different folding options for optical layout. — Now one baseline layout that meets access requirements & fits accessories. — Not possible to combine the shutter and the Hartmann door function. — Dichroics are specific to only one option now. • • Smaller nominal illuminated area on the detector. Added details about dichroics. Added more details about gratings. Slightly changed blue grating specs. Smaller operating temperature range. Separated Survival Temperature specifications into “shipping” (-20 to 60) and “on-mountain” (-20 to 30). Larger shutter (has to clear the reflection from fold mirror). Simpler drawing of FTS Lab. 3
BB_SPEC_20121213. ZAR spectrograph
Spectrograph Layout with accessories Collimator Mirror • • Optics-only volume ~0. 9 m x 1. 3 m x 0. 4 m. Two aspheres per camera. Oiled Triplets in cameras. Single lens/window at each cryostat. — Slightly tilted relative to the rest of the camera. • • • Good access to cryostats. Good spacing between cryostats. Good access to slithead. Larger shutter. Tight fit in some places. — e. g. VPHG/camera clearance. 5
Spectral Resolution (with Detector) Arm Blue Arm Red Arm NIR Arm Pixel Scale (Å/pixel) 0. 59 0. 53 0. 60 • 6
Weighted Spectral Resolution • Weighted Resolution Function • ti(λ) is the throughput of arm i at wavelength λ • Ri(λ) is the resoution of arm I at wavelength λ • 7
Encircled Energy EE 50 Diameter EE 95 Diameter No Requirement currently Requirement = <110 µm • 8
Throughput Spectrograph Throughput Camera/Collimator/Fold Flat Throughput • 9
Blue Camera Manufacturing Diameter Lens (mm) Blue L 1 Blue L 2 Blue L 3 Blue L 4 Blue L 5 Aspheric Surface Blue L 1 surface 1 Blue L 5 surface 1 159. 1 162. 7 179. 6 208. 8 94. 6 Mass (kg) 1. 721 3. 411 3. 571 3. 703 0. 250 Vertex Edge Material Thickness (mm) Ca. F 2 38. 2 14. 9 N-BAK 2 19. 0 75. 0 Ca. F 2 70. 3 11. 3 Ca. F 2 59. 4 7. 5 SILICA 9. 0 23. 1 Best fit Maximum depth Volume Maximum Sphere radius to remove Slope 3 (mm) (mm ) Deviation -483. 934 0. 813 1. 08 E+04 0. 090 97. 878 0. 294 6. 72 E+02 0. 050 • 10
Red Camera Manufacturing Vertex Edge Diameter Mass Lens Material Thickness (mm) (kg) (mm) Red L 1 167. 8 4. 984 CAF 2 70. 1 57. 6 Red L 2 178. 0 4. 685 LF 5 29. 6 75. 0 Red L 3 190. 2 4. 612 CAF 2 75. 1 18. 1 Red L 4 216. 9 4. 073 N-BK 7 70. 0 17. 3 Red L 5 95. 8 0. 274 SILICA 10. 0 24. 4 Best fit Maximum depth Volume Maximum Slope sphere radius to remove Deviation (mm) (mm 3) Red L 1 surface 1 -414. 612 0. 749 1. 10 E+04 0. 079 Red L 5 surface 1 101. 005 0. 290 6. 78 E+02 0. 048 Aspheric Surface • 11
NIR Camera Manufacturing Vertex Edge Diameter Mass Lens Material Thickness (mm) (kg) (mm) NIR L 1 166. 7 4. 590 CAF 2 70. 0 49. 6 NIR L 2 176. 5 3. 971 LF 5 16. 8 70. 0 NIR L 3 190. 8 4. 015 CAF 2 70. 0 11. 7 NIR L 4 217. 4 4. 096 N-BK 7 70. 0 17. 2 NIR L 5 96. 3 0. 277 SILICA 10. 0 24. 4 Best fit Maximum depth Volume Maximum Slope sphere radius to remove Deviation (mm) (mm 3) NIR L 1 surface 1 471. 277 0. 849 1. 23 E+04 0. 090 NIR L 5 surface 1 -101. 324 0. 270 6. 43 E+02 0. 045 Aspheric Surface • 12
Specification • Some tables and figures from spec reproduced in this slideshow to allow discussion and clarifications, if needed. 13
Spectrograph Integration Block Diagram (unchanged) 14
Imaging Spec (unchanged) 15
Nominal Illuminated Area • Due to ‘distorted’ pixels plus manufacturing and alignment tolerances, this is the size of the rectangle that the nominal design should project light into: 16
Dichroic 17
Grating • Note that the VPHG vendor’s small table produces VPHGs with C. A. up to ~140 mm-147 mm diameter. 18
Slit (unchanged) 19
Slit/Fold Mirror (1) 20
Slit/Fold Mirror (2) Face View Collimator View Effective Slit Width = 2. 5 mm 172 mm Close up Showing Beam Clearance 280 mm Side. View • 21
Environmental Spec • • On-Mountain Survival: spectrograph assemblies themselves must survive. Shipping Survival: shipping container must survive and not allow the spectrograph assembly to violate the On-Mountain Survival Temperature. 22
Accommodations
Shutter/Fiber Illuminator • 600 mm x 380 mm x 26 mm • pneumatic actuator • LED array on fiber side of shutter illuminates fibers for Fiber View Camera Fiber Illuminator LED Array Aligned with slit when shutter is closed 24
Hartmann Door Assembly • 420 mm tall • 85 mm radius doors • pneumatic actuators Actuators Swing Volume Door 25
Cryostat • Provides Tip/Tilt/Focus • Interface with spectrograph TBD 26
FTS Lab • Room where spectrographs install on the mountain 27
Backup Slides
Blue Camera Prescription ROC=1/c Thickness (mm) 1 EVENASPH Blue L 1 -333. 141 -38. 175 2 STANDARD Oil 207. 036 -0. 076 3 STANDARD Blue L 2 207. 036 -18. 968 4 STANDARD Oil -122. 024 -0. 076 5 STANDARD Blue L 3 -122. 024 -70. 278 6 STANDARD 236. 287 -26. 903 7 STANDARD Blue L 4 -278. 565 -59. 382 8 STANDARD 187. 854 -146. 977 9 COORDBRK Infinity 0. 000 10 STANDARD Blue Window 89. 137 -9. 000 11 STANDARD -559. 011 -4. 937 12 STANDARD Detector Infinity 0. 000 # Type Surf Diameter Conic=k A 2 A 4 (mm) CAF 2 159. 1 0. 0000 0. 000 E+00 6. 320 E-08 C-5610 162. 7 0. 0000 0. 000 E+00 N-BAK 2 162. 7 0. 0000 0. 000 E+00 C-5610 179. 5 0. 0000 0. 000 E+00 CAF 2 179. 6 0. 0000 0. 000 E+00 188. 3 0. 0000 0. 000 E+00 CAF 2 208. 8 0. 0000 0. 000 E+00 208. 5 0. 0000 0. 000 E+00 Decenter X Decenter y Tilt X 0. 0000 -0. 2054 -0. 2397 SILICA 94. 6 -1. 4146 0. 000 E+00 93. 0 0. 000 E+00 83. 3 0. 0000 0. 000 E+00 Glass A 6 A 8 1. 700 E-12 0. 000 E+00 0. 000 E+00 Tilt Y 0. 0000 0. 000 E+00 5. 647 E-17 0. 000 E+00 0. 000 E+00 Tilt Z 0. 0000 0. 000 E+00 • 29
Red Camera Prescription ROC=1/c Thickness Diameter Glass Conic=k A 2 A 4 (mm) 1 EVENASPH Red L 1 -313. 959 -70. 081 CAF 2 167. 8 0. 0000 0. 000 E+00 4. 725 E-08 2 STANDARD Oil 1020. 487 -0. 076 C-5610 178. 0 0. 000 E+00 3 STANDARD Red L 2 1020. 487 -29. 570 LF 5 178. 0 0. 000 E+00 4 STANDARD Oil -129. 500 -0. 076 C-5610 190. 2 0. 0000 0. 000 E+00 5 STANDARD Red L 3 -129. 500 -75. 143 CAF 2 190. 2 0. 0000 0. 000 E+00 6 STANDARD 334. 003 -5. 000 201. 1 0. 0000 0. 000 E+00 7 STANDARD Red L 4 -240. 004 -70. 020 N-BK 7 216. 9 0. 0000 0. 000 E+00 8 STANDARD 228. 352 -137. 488 214. 8 0. 0000 0. 000 E+00 Decenter X Decenter y Tilt X 9 COORDBRK Infinity 0. 0000 -0. 1503 -0. 1223 10 STANDARD Red Window 92. 045 -10. 000 SILICA 95. 8 -1. 4609 0. 000 E+00 11 STANDARD -485. 337 -5. 260 93. 6 0. 0000 0. 000 E+00 12 STANDARD Detector Infinity 0. 000 83. 4 0. 0000 0. 000 E+00 # Type Surf A 6 A 8 1. 187 E-12 0. 000 E+00 0. 000 E+00 Tilt Y 0. 0000 0. 000 E+00 3. 507 E-17 0. 000 E+00 0. 000 E+00 Tilt Z 0. 0000 0. 000 E+00 • 30
NIR Camera Prescription # 1 2 3 4 5 6 7 8 9 10 11 12 ROC=1/c Thickness Diameter Glass Conic=k A 2 A 4 (mm) EVENASPH NIR L 1 332. 888 70. 041 CAF 2 166. 7 0. 0000 0. 000 E+00 -5. 369 E-08 STANDARD Oil -305. 898 0. 076 C-5610 176. 5 0. 0000 0. 000 E+00 STANDARD NIR L 2 -305. 898 16. 840 LF 5 176. 5 0. 0000 0. 000 E+00 STANDARD Oil 133. 303 0. 076 C-5610 190. 8 0. 0000 0. 000 E+00 STANDARD NIR L 3 133. 303 70. 031 CAF 2 190. 8 0. 0000 0. 000 E+00 STANDARD -284. 201 7. 743 199. 6 0. 0000 0. 000 E+00 STANDARD NIR L 4 254. 271 70. 010 N-BK 7 217. 4 0. 0000 0. 000 E+00 STANDARD -219. 682 145. 613 216. 0 0. 000 E+00 Decenter X Decenter y Tilt X COORDBRK Infinity 0. 0000 0. 7676 -0. 1689 STANDARD NIR Window -92. 978 10. 000 SILICA 96. 3 -1. 3549 0. 000 E+00 STANDARD 502. 862 5. 187 93. 7 0. 0000 0. 000 E+00 STANDARD Infinity 0. 000 83. 4 0. 0000 0. 000 E+00 Type Surf A 6 A 8 -1. 363 E-12 0. 000 E+00 0. 000 E+00 Tilt Y 0. 0000 0. 000 E+00 -5. 353 E-17 0. 000 E+00 0. 000 E+00 Tilt Z 0. 0000 0. 000 E+00 • 31
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