PowerPoint Presentation

Document Sample
PowerPoint Presentation Powered By Docstoc
					               Prime Focus Imaging
                   Spectrograph
                       Status
• Engineering Status
    Optics
    Mechanical
    Control System
• Management
    Budget
    Schedule



Oct 10, 2002             SSWG        1
                   Optics

•   Design Updates
•   Slit Throughput
•   VPH Grating Complement
•   Optomechanical
•   Concerns
•   Procurement plan




Oct 10, 2002          SSWG   2
                  Optics Design

• Updated camera and collimator to final indices
    – ~ 20% image quality degradation;
       • decrease manufacturing margin?
       • relieve spec?
• Completed thermal design. Focus in camera
• Updated pupil placement and fold mirror position
  for maximum NIR collimated beam            Details
• Fused silica -> fused quartz in common collimator
  beam (for NIR)                             Details
• Camera configuration update        Details

Oct 10, 2002               SSWG                    3
                 Slit Throughput

• PDR: “max resolution 6250 overstated”. Used
  median seeing 0.9 arcsec, not telescope image
• Model using seeing degraded to 37 deg ZD, actual
  SAC, actual PFIS model
    – In median seeing, a 1.25 arcsec slit will give 70%
      throughput
    – Resolution at a given grating angle reduced to 70%.
• Found can increase maximum articulation of
  camera to 100 deg, increases max resolution 20%:
  R = 5500 at 50 deg tilt, 1.25 arcsec slit
Oct 10, 2002                SSWG                            4
               Spectral Resolution vs. Throughput




Oct 10, 2002                 SSWG                   5
               VPH Grating Complement

• VPH procurement in next 6 months, tradeoff
  required: UV efficiency vs high resolution
  efficiency
• Suggest: efficiency in UV for highest and lowest
  density gratings; efficiency at high resolution for
  other three
• Note that SALT can easily add VPH gratings-
  magazine designed for swapout


Oct 10, 2002             SSWG                           6
               VPH tradeoff




Oct 10, 2002        SSWG      7
                  Optomechanical

• Largest PDR risk: optics, especially
  optomechanical, underbudgeted
• Award subcontract for optomechanical to J. Alan
  Schier
    – optomechanics for Keck ESI, DEIMOS
    – comfortable with fluid coupling, salt, solgel
• Tasks
    – mounting tolerancing
    – design, fabricate lens holders
    – assemble lens groups

Oct 10, 2002                 SSWG                     8
                 Current concerns

• Coating strategy
    – baseline: solgel on interior surfaces; hard elsewhere
    – cost poorly defined
• Stress birefringence in collimator potentially
  degrading polarimetric efficiency
    – blanks: NaCl possible problem; lack of data       Details
    – 4 CaF2 blank costs may be increased
    – investigating VPH and etalon effects



Oct 10, 2002                 SSWG                                 9
                 Optics procurement

• before CDR
    –   third etalon (before year’s end to get good price)
    –   fold flat/ coating
    –   camera/ collimator blanks
    –   grating blanks
• just after CDR
    – camera/ collimator figuring
    – waveplates, beamsplitter
    – VPH gratings


Oct 10, 2002                   SSWG                          10
               Structure/ Mechanisms
• Structure
    – guide mount interface designed
    – collimator assembly
• Mechanisms designed
    –   waveplate
    –   slitmask
    –   grating. 6 grating complement
    –   camera articulation.
          • Will do full articulation in < 20 sec (enable PFIS
            imaging mode as slitmask setup)
          • Articulate to 100 deg                              Details

Oct 10, 2002                   SSWG                             11
                  Control System

• Hardware
    – generic mechanism test bed operational: use for
      LabView learning curve, answering operational
      questions for mechanism designs
    – wiring architecture; box placement; cable harness
• Software
    – actually operating hardware
    – prototype client / server, scripting developed
    – consistent with telescope architecture
                                                          Details

Oct 10, 2002                 SSWG                          12
                Management

• Budget re-projection
• Schedule




Oct 10, 2002             SSWG   13
               Cost-to-Completion Deltas

                             Base Dollars

                  PDR          ’02 Q1       ’02 Q2      ’02 Q3

    UW          $2,426,501   $2,616,194   $2,675,390   $2,814,391

    Tot         $3,645,947   $3,835,640   $3,929,229   $4,068,574

    Delta                     $189,693     $93,589     $139,345
    %
                                26           39           58
    Cont



Oct 10, 2002                      SSWG                              14
                    Chief Deltas

• Q1-2 ($94K)
    – CDR electrical engineering underestimate $15K
    – SAAO Cryotiger, etc $25K
    – US$ slowed inflation $50K
• Q2-2 ($139K)
    – Drafting subcontract underestimate: $97K - $50K -
      $20K = $27K. Control mech design schedule risk.
    – Optomechanical subcontract: $220K - $50K - $20K =
      $150K. Control optics technical/ schedule risk; biggest
      PDR budget deficiency

Oct 10, 2002                 SSWG                           15
                          Prognosis

• Contingency use (58%) somewhat above expected (50%)
  at this point, but still on track. Remaining deltas will be
  much better known at CDR:
• Capital purchases. Preliminary RFQ’s on largest
    – likely increases: CaF2 blanks; coatings
    – likely savings: mechanisms/controls; lens fabrication; slitmask mill
• Schedule. Remaining contingency would cover 8 months
  slip.
• When do we start spending contingency? At current rate,
  Q1 ’04; at rate which would spend cap, Q4 ’03 (well after
  CDR)

Oct 10, 2002                      SSWG                                  16
                            Schedule
• Milestone: CDR 17 Mar, 2002
    – slipped 2 months from PDR; mechanical design critical path
    – recover: drafting/ engineering subcontract help
• Optical
    – optomechanical subcontract kickoff
    – procure blanks, issue pre-CDR RFQs
• Mechanical: 4 most complex mechanisms completed
• Control System: in progress
    – hardware wiring diagram
    – Labview design well under way
• Detail fabrication/ testing schedule in work this month
                                                                   Details

  Oct 10, 2002                     SSWG                             17
               Done!




Oct 10, 2002     SSWG   18
               Optics Details




Oct 10, 2002         SSWG       19
                                      NIR Beam

                                                       20+/- 20 mm      NIR Beam (future)
                              Fold/ Dichroic
               Articulation                         Fold
               Axis


                                                                     Articulation
                                                               Pupil Axis
                                                           Focus
   Visible Camera

                              Pupil                        Collimator




                                      Focal plane

Oct 10, 2002                                   SSWG                                     20
                Filters    Focus               (Polarizing
                                               beamsplitter




                 CCD         Camera            (Etalons)

                                                   Collimator
                Side View (Fabry-Perot)            (Waveplates)

   Optics                                          Focal Plane

Configuration      CCD                         (Etalons)



                                                      Shutter
                     Fabry-Perot
                                   (Grating)


                     VPH
                     Spectroscopy
                     (maximum
                     articulation)

                Top View
 Oct 10, 2002                 SSWG                         CCD    21
                         Camera
                         Asphere                  CaF2
                         MAD = 0.45mm
• triplet modification
   – CaF2 -> silica
   – “aplanatic”
      configuration
                                                              NaCl
• reduced MAD on                         Silica
  asphere                Asphere
                                                         Focus group
                         MAD = 0.35 mm
• focus singlet +
  triplet



                                                              NaCl
Oct 10, 2002                 SSWG                                      22
               Birefringence Budget

• Unusual SALT configuration puts large glass path (17
  cm!) between waveplate and beamsplitter
• Stress birefringence at 45° to polarimetric axis causes
  depolarization d ~ (π w)2 (w = biref in waves). d < 2% =>
  w <~ 1/20 wave, biref/cm <~ 2-10nm/cm
• Have birefringence budget for
    –   Fused silica, quartz: 1 -5 nm/cm
    –   CaF2: 1-2 available at extra cost
    –   NaCl: unknown. sample now being measured
    –   Folding flat LLNL coating
    –   VPH grating
    –   Etalon


Oct 10, 2002                   SSWG                      23
               Mechanical Details




Oct 10, 2002           SSWG         24
                     Completed Designs

                                gratings


               slitmask
                            collimator
                            assembly




                                           camera
                                           articulation

Oct 10, 2002       waveplates     SSWG             25
                Camera Articulation

                         camera tube


                                       gearbox/
                                       motor




                                                  pinion
                  pneumatic
bearing
                  detent, 0.5 deg
                  spacing
 Oct 10, 2002                 SSWG                         26
               Camera Support




Oct 10, 2002         SSWG       27
                       Grating Mechanism
          pneumatic
          insertor


                                      linear stage
                                      selector
6 gratings



             grating
             rotator




  Oct 10, 2002                 SSWG                  28
                    Collimator Assembly

               main collimator
               group
                                                 slitmask magazine




                guider feet             waveplates
Oct 10, 2002                     SSWG                           29
               Waveplate Mechanism


                               halfwave plate


                                          quarterwave plate

      blank




Oct 10, 2002            SSWG                              30
               Slitmask Mechanism - 1


   linear stage
   selector

                                     magazine




                                  pneumatic
        mask in position          insertor

Oct 10, 2002               SSWG                 31
                 Slitmask Mechanism - 2




               pneumatic
               extractor




Oct 10, 2002               SSWG           32
               Control System Details




Oct 10, 2002             SSWG           33
               Generic Mechanism

• Test Hardware
    – candidate motor, encoders,
      hall sensors, pneumatic
    – motor drivers
    – signal conditioner
    – PXI motor card, I/O card




Oct 10, 2002                SSWG   34
                 LabView

• Hierarchical      Controller
                    Controller
                   Controller      Stepper
                                    Stepper       Pneumatic
                                                 Pneumatic
                                                  Pneumatic

                                                                                          Stepper Data

  VI’s                                                                                            Home
                                 Initialize


• Commandable                                                          Controller Data       Pneumatics Data
                                  Port 1 On               Port 1 Off                              Index
                                      Position
                                       0                                    Initialized
                                                                                                   Port 1
  from scripts                   Enable               Disable

                                                                             Enabled
                                                                                                  Moving


                                  Port 2 On
                                    Set Position          Port 2 Off                               Port 2
                                                                                                  Fwd Limit
                                 Kill                 Unkill                Killed

                                                                                                   Fwd Limit
                                                                                                  Rev Limit
                                                                            Homed
                                    Adjust Position
                                 Home
                                                                            Indexed                Rev
                                                                                                  Steps Limit
                                                                                                   0

                                 Index                                                            Quadrature Counts
                                                                                                   0

                                                                                                  Cable Sensor
                                                                                                   0




                  Tab Control
                  Tab Control



 Oct 10, 2002              SSWG                                                                                  35
               Management Details




Oct 10, 2002           SSWG         36
ID    Task Name                                                                      1st Quarter                                   2nd Quarter                  3rd Quarter                                        4th Quarter                                           1st Quarter
                                                                         D                  J               F          M                 A        M     J             J              A                S                  O                    N                   D             J                 F                     M
 1    Prime Focus Imaging Spectrograph
17        Phase 3 - Critical Design                                                                                                                                                                                                                                                                                          57%




                                                                              Detail CDR Schedule
18            System Review                                       100%
19            Critical Optical Design                                                                                                                                                                                                                  78%
20                Image Motion Analysis                               100%
21                Throughput Resolution Analysis                  s                                  100%
22                Mounting Sensitivity Analysis                   s           100%
23                Final Collimator Design                             3 wks               100%
24                Final Camera Redesign                                         3 wks                100%
25                Preliminary Thermal Analysis / Design                                      3 wks              100%
26                Final Thermal Analysis / Design                                                    19.4 wks                                                        100%
27                Prepare SPIE paper                                                                                                                        5 days     100%
28                Update Optical Design Document                                                                       6.15 days                                                      100%
29                RFP For Optomechnaical Design                                                                                                                                          100%
36                Fold Mirror Specification                                                                                                                                              100%
38                RFP For Camera / Collameter Optical Design                                                                                                                                                            65%
45                Grating Substrates Specification                                                                                                                                                                0%
48                Slit Mask Factory                                                                                                                                                                                            0%
51                Waveplates                                                                                                                                                                                            0%
54                Beam Splitters                                                                                                                                                                                                    0%
57                Slit Viewers                                                                                                                                                                                                           0%
60                VPH Grating                                                                                                                                                                                                             0%
62                SR Gratings                                                                                                                                                                                                                     0%
64                Color Filters                                                                                                                                                                                                                        0%
66            Critical Mechanical Design                                                                                                                                                                                                                                                                              54%
67                PFIS Structure                                                                                                                                                                            52%
73                Critical Wave Plate Design                                                                                                                                                                      86%
78                Critical Slitmask Design                                                                                                                             81%
83                Mount Foot for Guider                                                                                                                                62%
87                Critical Grating Design                                                                                                                                                           88%
93                Critical Articulation Design                                                                                                                                                                            54%
99                Critical Filter Design                                                                                                                                                                                                                     0%
105               Focus Camera                                                                                                                                                                                                                                                    0%
110               Critical Etalon Design                                                                                                                                                                                                                                          0%
112               Camera Tubes                                                                                                                                                                                                                                                               0%
115               Focus (Collimator) Design                                                                                                                                                                                                                                                           0%
118               Critical Shutter Design                                                                                                                                                                                                                                                             0%
121               Critical Polarizer Design                                                                                                                                                                                                                                                                           0%
125           Critical Control System Design                                                                                                                                                                                                                                                                    30%
126               Generic Mechanism                                                                                                                                                                        100%
132               Client / Server Design                                                                                                                                             11.63 days             80%
133               User Interface Design                                                                                                                                                       17.44 days                      0%
134               User Interface prototype                                                                                                                                                                  17.44 days                    0%
135               Wiring Diagram and Grounding & Switching Plan                                                                                                                                                                                                                                                 26%
145               Scripting Lannguage                                                                                                                                                                                                                                 38%
148               Slitmask                                                                                                                                                                                                                             0%
151               Wave Plate                                                                                                                                                                                                                                  10%
154               Other Mechanisms                                                                                                                                                                                                                                                     0%
162               Interlock Design Document (Whole)                                                                                                                     11.5 days?           100%
163               Final Mechanism Control Design (Whole)                                                                                                                                                                                                              5.56 days         0%
164               Power and Thermal Budget                                                                                                                                                                                                                               2.22 days          0%
165               Interface Control Documents                                                                                                                                                                                                                                                              0%
169           Prepare CDR Package                                                                                                                                                                                                                                                                 10 days               0%
170
                          Oct 10, 2002
              Critical Design Review
                                                                                                                                                 SSWG                                                                                                                                   37                      1 day       0%

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:20
posted:9/13/2012
language:Latin
pages:37