The Design Improvement of TMT Laser Guide Star Facility Kai Wei Institute of Optics and Electronics...
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- Slide 1
- The Design Improvement of TMT Laser Guide Star Facility Kai Wei
Institute of Optics and Electronics (IOE),CAS 1 International
Colloquium on Thirty-Meter Telescope Beijing, May 25 2011 2011 May
25
- Slide 2
- Simple Description of the LGSF main Requirement Why we need
update the LGSF conception design? The updated LGSF conception
design Optical design Mechanical design Electronics and Control
Management Plan Presentation Outline 22011 May 25
- Slide 3
- TMT.LGSF main Requirement The LGSF is composed of 3 main
sub-systems: The Laser System (LAS), which includes the lasers, the
Laser Service Enclosure (LSE) and all associated electronics
(TIPC); The Beam Transfer Optics (BTO) and LGSF Top End: The Beam
Transfer Optical (BTO) ; Diagnostic Optical Bench system (DOB);
Asterism Generation system (AG); Laser Launch Telescope (LLT);
Acquisition Telescope (AT); The Laser Safety System (LSS), which
will copy the Geminis LSS; 32011 May 25
- Slide 4
- TMT.LGSF main Requirement The LGSF is composed of 3 main
sub-systems: The Laser System (LAS), which includes the lasers, the
Laser Service Enclosure (LSE) and all associated electronics(TIPC);
The Beam Transfer Optics (BTO) and LGSF Top End: The Beam Transfer
Optical (BTO) ; Diagnostic Optical Bench system (DOB); Asterism
Generation system(AG); Laser Launch Telescope (LLT); Acquisition
Telescope (AT); The Laser Safety System (LSS), which will copy the
Geminis LSS; 42011 May 25
- Slide 5
- TMT.LGSF main Requirement 52011 May 25
- Slide 6
- TMT.LGSF main Requirement Main System Functions Project the
early light NFIRAOS asterism Project other asterisms as required by
the AO modes Switch rapidly between the four asterisms Use
conventional optics for the Beam Transfer Optics and launch the AO
asterisms from a Laser Launch Telescope located behind the TMT
secondary mirror 62011 May 25
- Slide 7
- Asterism generation requirement NFIRAOS asterism: consists of 6
LGS, 5 equally spaced on a circle of radius of 35 arcsec and one
additional on-axis guide star. (black) MIRAO asterism: consists of
3 LGS equally spaced on a circle of radius of 70 arcsec. (red) MOAO
asterism: consists of 8 LGS, 3 equally spaced on a circle of radius
of 70 arcsec and 5 equally spaced on a circle of radius of 150
arcsec. (blue) GLAO asterism: consists of 5 LGS, 4 equally spaced
on a circle of radius of 510 arcsec and one additional on-axis
guide star. (green) switch between asterisms within 2 minutes
TMT.LGSF main Requirement 72011 May 25
- Slide 8
- Why we need update the LGSF conception design 8 ~50m Beam
Transfer Optics Optical Path with 110 total actuators. 2006: LGSF
Conceptual Design with Launch Telescope behind M2 and Laser System
attached to Elevation Journal 2008: LGSF Update Work Redesign of
LGSF Top End to compensate for telescope top end flexure Relocation
of Laser System to azimuth structure to allow the lasers to operate
in fixed gravity orientation 2010: Intensive trade study to compare
center launch versus side launch Center Launch confirmed Relocation
of Laser System to Elevation Journal due to progress toward
smaller, lighter and more robust 20 to 25W lasers with a design
compatible with a changing gravity orientation Our work begins at
2010.11 based on NOAOs Conceptual Design 2011 May 25
- Slide 9
- LGSF Top End Issues 9 LGSF Top End: 0.4m telescope instead of
0.5m repackage the sub-system at the Top End structure Launch
Telescope field of view trade study(increase the FOV from 5 to 17)
No optical path to observe with natural guide stars for
calibrations Wind jitter goal < 27.5m(Old 2008 LGSF structure
design ~ 27.82m) New Acquisition System: independent LGS
acquisition system with small telescope 28000 23593 25926 2011 May
25
- Slide 10
- 10 Several issues with the old path: Interference with the (-X,
-Y) edge of the -X Nasmyth platform for elevation angles > 80
deg Requires a notch in the Nasmyth platform Interference between
EJFA2 and (- X, +Y) part of the X Nasmyth platform for elevation
angles < -3 deg Requires another notch in the Nasmyth platform
Tight clearance between Elevation Journal and Nasmyth platform edge
of 350mm. Beam Transfer Optics Path Issues 102011 May 25
- Slide 11
- The updated LGSF conception design 11 2008 LGSF Design 2011
LGSF Design 2011 May 25
- Slide 12
- The updated LGSF conception design 12 2008 LGSF Design 2011
LGSF Design 2011 May 25
- Slide 13
- The updated LGSF conception design 13 2008 LGSF Top end Design
Flexure Compensation System LLT Side View Flexure Compensation
System Top View 2011 LGSF Top end Design Side View 2011 May 25 Top
View
- Slide 14
- LLT Optical Redesign (1/3) 14 Reduce the Diameter from 500mm to
400mm Change the Angular Magnification from 60 to 48 Change the
Primary Mirror from hyperboloid to paraboloid Remove the two
Aspheric surfaces in the system Reduce the Distance between the M1
and M2 for about 50mm Shift the pupil position nearly about 100mm
Side View 2011 May 25
- Slide 15
- LLT Optical Redesign (2/3) 15 Radius of field angle (arc-sec)
90Km210Km WFESrWFESr 00.0170.9900.0050.999 35 (+y
direction)0.0170.9890.0070.998 35 (-y
direction)0.0170.9890.0070.998 35 (+x
direction)0.0170.9890.0070.998 35 (-x
direction)0.0170.9890.0070.998 70 (+y
direction)0.0180.9870.0110.996 70 (-y
direction)0.0180.9870.0100.996 70 (+x
direction)0.0180.9870.0100.996 70 (-x
direction)0.0180.9870.0100.996 Radius of field angle (arc-sec)
90Km210Km WFESrWFESr 150 (+y direction)0.0210.9820.0190.985 150 (-y
direction)0.0210.9820.0180.988 150 (+x
direction)0.0210.9820.0190.986 150 (-x
direction)0.0210.9820.0190.986 510 (+y
direction)0.0390.9420.0450.923 510 (-y
direction)0.0110.9950.0140.992 510 (+x
direction)0.0280.9690.0330.958 510 (-x
direction)0.0280.9690.0330.958 Image quality of the new LLT 2011
May 25
- Slide 16
- LLT Optical Redesign (3/3) 16 NOAO Design(2008) M1/M2
Hyperboloid M1 Paraboloid M2 Hyperboloid M1 Paraboloid M2
Paraboloid M1HyperboloidParaboloid M2Hyperboloid Paraboloid Exit
Pupil Diameter 500400 Angular Magnification 6048 Fields 17 Image
wavelength Both 550nm&589nm589nm Elements quantities Add one
lens near the collimator Aspheric Surface 2None Image Quality
(Gauss Beam Sr@589nm) 0 arc-second Near 0.970.98830.9888 35
arc-seconds Near 0.970.98810.9758 70 arc-seconds Near
0.970.98750.9643 150 arc-seconds Near 0.970.98460.9651 510
arc-seconds 0.860.95580.5359 M1 parameters Radius No
Data1677.191708.40 Conic coefficient No Data Off axis decenter No
Data420 Aperture No Data450460 M2 parameters Radius No
Data213.91155 Conic coefficient No Data-1.269 Off axis decenter No
Data50.438.1 Aperture No Data 56(3.2mm more)43(3.2mm more)
Fabrication Tolerance for M1 Radius No Data 10mm(AM-47.7~48.3 )
Conic coefficient No Data 0.0002(PV error 0.0068)0.0002(PV error
0.0083)* Fabrication Tolerance for M2 Radius No Data
1.6mm(AM-47.7~48.3 )1.6mm(AM-47.6~48.2) Conic coefficient No Data
0.004(PV error 0.0015)0.002(PV error 0.0093) Focus adjustments(90Km
to 210Km) No DataCollimator move 0.983mmCollimator move 0.109mm On
axis image quality (Without focus adjustment) No
Data0.98830.92440.98880.8339 On axis image quality (Witt focus
adjustment) No Data0.98830.99910.98880.9889 Entrance Pupil
Position(Distance from K-Mirror) No Data345mm368mm 2011 May 25
- Slide 17
- Beam Transfer Optical Redesign (1/2) 17 Old BTO DesignNew BTO
Design Laser System LGSF TOP End Laser System LGSF TOP End Move one
mirror from the Nasmyth Platform to the LGSF Top End structure 2011
May 25
- Slide 18
- Beam Transfer Optical Redesign (2/2) 18 Input beam shapeOutput
Beam shape Three relay lenses reimage the laser output pupil to the
LLT entrance pupil Left figure shows the input beam shape of the
BTO which also is the laser output beam shape, right figure shows
the output beam shape on the LLT entrance pupil The line of sight
wander between telescope pointing at zenith and 65 degrees is
proceeded 2011 May 25
- Slide 19
- Acquisition Telescope Optical Design(1/2) 19 One lens and two
mirrors, total length is about 570mm Field of the design is larger
than 5 arcmins R band (556nm~696nm),Focal Length:5360mm Aperture:
150mm 2011 May 25
- Slide 20
- Acquisition Telescope Optical Design(2/2) 20 Radius of field
angle (arc-sec)Image Quality(Sr) @589nm@R Band 00.9840.953 35 (+y
direction)0.9770.947 35 (-y direction)0.9770.947 35 (+x
direction)0.9770.947 35 (-x direction)0.9770.947 150 (-y
direction)0.9720.942 150 (+x direction)0.9720.942 150 (+x
direction)0.9720.942 150 (-x direction)0.9720.942 Image quality of
the Acquisition Telescope 2011 May 25
- Slide 21
- Throughput Budget of the End to End LGSF Optical System 21
Level 1Level 2Level 3ElementsSurfaceSurface
throughputThroughputTotal Throughput LGSF (the Requirement of the
total throughput is 0.75 REQ-2-LGSF-0650)0.779 LOM (Laser System
Output Mirrors)110.999 BTO0.937 EJFA (EJ Fold Pointing
Array)110.999 TA (Truss Array)110.999 TRIFA (Tripod Fold
Array)110.999 TCA (Truss Centering Array)110.999 TEFA (Top End Fold
Array)110.999 Relay Lenses360.9900.941 DOB0.970 QWP120.9950.990 BS
(Beam Splitter)120.9900.980 AG0.992 Fold Mirror330.9990.997 Fast
Mirror110.995 LLT0.864 Collimator Lenses240.9900.961 Fold
Mirror110.999 K Mirror330.9990.997 M2110.980 M1110.960
Window120.9800.960 End to end optical evaluation is in progress
2011 May 25
- Slide 22
- LGSF Top End Mechanical Redesign (1/6)-DOB Repackaging 22 Old
DesignNew Design Periscope21 Shutter1No Beam Splitter21 Beam
TrapNo1 Dimension of the Bench1100 X 8001000 X 710 Repackaging 2011
May 25
- Slide 23
- LGSF Top End Mechanical Redesign (2/6)-LLT Repackaging 23
2450mm 1170mm 1040mm 850mm 710mm Repackaging 2011 May 25
- Slide 24
- LGSF Top End Mechanical Redesign (3/6)-AG Repackaging 24
Repackaging D=725mm D=625mm 17 13.6 2011 May 25
- Slide 25
- LGSF Top End Mechanical Redesign (4/6)-AT packaging 25
Acquisition Telescope The total length of the acquisition telescope
is 736.5mm 2011 May 25
- Slide 26
- LGSF Top End Mechanical Redesign (5/6)-Support Structure 26 DOB
Support TCA Support Tilt Compensation LLT Support 2011 May 25
- Slide 27
- LGSF Top End Mechanical Redesign (6/6)-Wind Section and Mass
budget 27 The maximum transverse cross sectional area of the LGSF
Top End is 2.74m 2 less than 4m 2 (REQ-2-LGSF-0750) The total mass
of the LGSF Top End is 0.98t (REQ-2-LGSF-0900) 2011 May 25
ItemSub-systemMass/Kg 1LLT213 2AG95 3DOB331 4TCA55 5Electronics
Box105 6Support structure185 7LGSF Top End total984
- Slide 28
- LGSF BTO Mechanical Redesign (1/4) 282011 May 25
- Slide 29
- LGSF BTO Mechanical Redesign (1/4) 292011 May 25
- Slide 30
- LGSF BTO Mechanical Redesign (3/4) 302011 May 25
- Slide 31
- LGSF BTO Mechanical Redesign (4/4) 31 Ducts structure and the
NFIRAOS laser position in the 3X3 array Laser Beam diameter: 5mm
Mirror diameter: 50mm 3x3 pattern Separation between beams:70mm
Duct diameter:270mm Duct :1mm thickness material rolled into
tubular section 2011 May 25
- Slide 32
- Electronics and Control (1/3)-The topology of the LGSF 322011
May 25 The LGSF electronics elements are divided into two parts:
Top end electronic enclosureTop end electronic enclosure Laser
Platform electronic enclosureLaser Platform electronic enclosure
The CPCI computer is the heart of the LGSF control LGSF
TopologyCPCI Topology
- Slide 33
- Electronics and Control (2/3)-Location of the Electronics Box
332011 May 25 Top End Electronics Box Dimension:1000x500x500
Weight:105Kg Elements in this Box MechanismVolume /weight Network
switch1U / 2.5kg Multi-view2U / 5kg Remote power switch1U / 3kg
CPCI3U / 15kg Motion controller&lifier8U / 40kg Fast
tip/tilt controller and driver 3U /20kg(supplied by JPL,,need to be
asserted.) Total18U /85.5kg When all the devices are running in the
full mode, the supplied power must be greater than 3063w.
- Slide 34
- Electronics and Control (3/3)- Location of the Electronics Box
342011 May 25 Laser platform Electronics Box Dimension:400x500x500
Weight:40Kg Elements in this Box MechanismVolume /weight Motion
controller2U / 5kg Motion amplifier3U / 15kg Network switch1U / 3kg
Remote power switch1U / 3kg Total7U / 26kg All the devices are
running in the full mode, the supplied power must be greater than
74w.
- Slide 35
- Management Plan 35 Conceptual Design Review at June 22
2011,Beijing Cost Estimate of the LGSF will begin after CDR and
finish in three months Cost Estimate Review at the end of September
Preliminary Design Part 1 will begin after Cost Estimate Review and
finish in four month Preliminary Design Part 1 Review at the end of
January 2012 2011 May 25
- Slide 36
- Management Plan 36 Schedule and Key milestone for this work
package Cost Estimate Review Preliminary Design Review 2011 May
25
- Slide 37
- Questions 37 Thank you! 2011 May 25