catania 28 feb – 01 mar 2011 v.viotto (inaf - osservatorio astronomico di padova) tou breadboard...
TRANSCRIPT
Catania 28 Feb – 01 Mar 2011
V.Viotto (INAF - Osservatorio Astronomico di Padova)
TOU BreadboardStatus and Test
General strategy for the AIV during Definition Phase
2 roadmaps have been followed to prove the AIV feasibility of the 32 telescopes:
1. INDUSTRY1. Paper study on the aspherical lens feasibility2. Paper study on the aspherical lenses procurement feasibility fitting our time
schedule3. Paper study on the spherical lenses procurement feasibility fitting our time
schedule4. Paper study on the albemet structures procurement feasibility fitting our time
schedule5. Paper study on the N-TOUs AIV feasibility fitting our time schedule
2. RESEARCH INSTITUTES1. Identify an AIV concept and procedure, defined in agreement with the industry2. Test on a TOU PRE-BreadBoard of the AIV procedure3. Test on the TOU BB of the warm/cold system performance, defined and
performed together with the industry4. Test on CaF2 blanks (vibration and thermal cycling)
TOU Alignment Concept
By using Airy and Newton rings both of the back reflected and of the By using Airy and Newton rings both of the back reflected and of the transmittedtransmitted
light (introducing one lens at a time) the alignment will be performed.light (introducing one lens at a time) the alignment will be performed.
In order to maximize fringes contrast and airy rings visibility:In order to maximize fringes contrast and airy rings visibility:1.1. the CCDs are mounted on linear stages which can move along the optical the CCDs are mounted on linear stages which can move along the optical
axisaxis2.2. light shields can be inserted between each lens, to isolate the back light shields can be inserted between each lens, to isolate the back
reflected light, when needed, coming only from that lensreflected light, when needed, coming only from that lens3.3. A variable diameter iris is inserted on the collimated beam, to maximize A variable diameter iris is inserted on the collimated beam, to maximize
the transmitted and back-reflected spot visibilitythe transmitted and back-reflected spot visibility
Laser
Beam Expander
Variable Iris
B/S
Back Reflected Light
Transmitted Light
FocussingCCD
FocussingCCD
Telescope
Laser
Beam Expander
Variable Iris
B/S
Back Reflected Light
Transmitted Light
Focussing CCD
FocussingCCD
TOU
TOU Alignment Set-Up: Vertical
To allow lenses insertionfrom the top, the finalalignment set-up for theBB will be vertical
Strategy for the Breadboard alignment
1. PRE-BreadBoard: LENSES: identification of commercial lenses with, as much as
possible, the same curvature of the final design lenses MECHANICS: commercial off-the -shelf mechanics AIM: to test the alignment procedure and learn from the test setup
▪ Airy and Newton rings visibility▪ decenter and tilt misalignment sensitivity▪ tuning of the test setup components, e.g. the movement range of the
detectors
2. BreadBoard: LENSES: set of lenses as close as possible to the final design
lenses, differing only for the glasses and for the usage of a spherical lens instead of the aspherical one
MECHANICS: realization of an “equivalent mechanical structure” (in term of thermal behavior and interface with FPA)
AIM: to perform the real TOU alignment procedure to validate in cold conditions the warm AIV check of the interface between FPA and TOU (under system group
responsibility)
TOU Pre-BreadBoard
Laser
Beam Expander
Variable Iris
B/S
Back Reflected Light
Transmitted LightFocussingCCD #1
FocussingCCD #2
AIV constraint: in the final system, L3 is on the pupil of the system AIV constraint: in the final system, L3 is on the pupil of the system and its mount connot be adjusted in tip-tilt and centeringand its mount connot be adjusted in tip-tilt and centering. .
First AIV step will be to align the laser beam to L3, which will be First AIV step will be to align the laser beam to L3, which will be the first lens to be mountedthe first lens to be mounted
Because of that, you need to rotate the TOU breadboard Because of that, you need to rotate the TOU breadboard accordingly to which lens you’re aligning, to see its back-reflected accordingly to which lens you’re aligning, to see its back-reflected spots…spots…
Laser
Beam Expander
Variable Iris
CCD#1
CCD#2
PLATOSIMULATOR
ChannelA
ChannelB
2 channels have been realized to 2 channels have been realized to simulate the TOU 180º rotation simulate the TOU 180º rotation
during AIVduring AIV
XYZ stages
Tip-tilt
mounts
TOU Pre-BreadBoard
Laser
Beam Expander
Variable Iris
CCD#1
CCD#2
ChannelA
Channel A: Channel A: CCD#1 - reflected lightCCD#1 - reflected lightCCD#2 - transmitted lightCCD#2 - transmitted light
TOU Pre-BreadBoard-Channel A
Laser
Beam Expander
Variable Iris
CCD#1
CCD#2
ChannelB
Channel A: Channel A: CCD#1 - transmitted lightCCD#1 - transmitted lightCCD#2 - reflected lightCCD#2 - reflected light
TOU Pre-BreadBoard-Channel B
TOU Pre-BreadBoard – Status
Test are still on going, also waiting for the final alignment tolerances, but
some points seem to be already clear:
2 back reflected Airy rings systems are visible for each lens Newton rings systems are visible for each lens Transmitted spot can always be used Centering sensitivity is always below 50μm (the precision is
higher for the first lenses integrated -> L3) Tip-tilt sensitivity is always below 50 arcsec
These results have been obtained inserting lenses with the following
sequence:L3-L2-L1-L4-L5-L6
Detectors have always been moved in a range shorter than 400mm
Frame connected to the bench, allowing the
rotation for lenses insertion from the top and their
alignment similarly to what would happen with the final
structure, withthe possibility to be
rotated of 180º to insertthe lenses from both sides
(L3 will be the first one)
TOU BreadBoard
Laser
Beam Expander
Variable Iris
B/S
Back Reflected Light
Transmitted Light
Focussing CCD
FocussingCCD
Rotating points
TOU Dummy Structure
Fixing points
Breadboard AIV tools
1. Light shields between each couple of lenses (TOU) TBD after pre-breadboard
2. Tools for lenses insertion (TOU&Dummy) Each lens mount will have three threaded holes (120deg separated), insertion will be performed thanks to 3 long threaded bars
3. Tools for lenses centering during alignment (TOU&Dummy) 4 screws (2 of them with springs) will be placed in correspondence of each lens mount. For the dummy 4 little blocks will be fixed to the flanges through threaded holes. The same blocks will be moved from one flange to the others during the alignment procedure.
Breadboard AIV tools
1. Light shields between each couple of lenses (TOU) TBD after pre-breadboard
2. Tools for lenses insertion (TOU&Dummy) Each lens mount will have three threaded holes (120deg separated), insertion will be performed thanks to 3 long threaded bars
3. Tools for lenses centering during alignment (TOU&Dummy) 4 screws (2 of them with springs) will be placed in correspondence of each lens mount. For the dummy 4 little blocks will be fixed to the flanges through threaded holes. The same blocks will be moved from one flange to the others during the alignment procedure.
Breadboard AIV tools
1. Light shields between each couple of lenses (TOU) TBD after pre-breadboard
2. Tools for lenses insertion (TOU&Dummy) Each lens mount will have three threaded holes (120deg separated), insertion will be performed thanks to 3 long threaded bars
3. Tools for lenses centering during alignment (TOU&Dummy) 4 screws (2 of them with springs) will be placed in correspondence of each lens mount. For the dummy 4 little blocks will be fixed to the flanges through threaded holes. The same blocks will be moved from one flange to the others during the alignment procedure.
GLUE act as an interface between metal and glass.A discussion to finalize the lens gluing operation inside their mounts is going on with the industry (SELEX GALILEO, SESO, SAGEM), in order to identify a procedure which is: safe for the lens, thinking also to vibrations and thermal excursion compatible with the tolerances reasonably achievable on the lens geometry (diameter above all)
Gluing operations
compatible with the centering and tilt tolerances of the lenses feasible in a fast way also by the industry (considering the huge number of lenses)
GOAL: freeze the gluing protocol today
B-PLAN: - formal offer from SESO
- discussion with SAGEM
Breadboard Status
Lenses: Seso will deliver them in a month Thermally equivalent structure: delivery
roughly in a month from Bern Lens mounts: some little modifications are
necessary, mounts production will start in the next days
Handling: the delivery is expected in a month Tools: easy to implement. They will be ready
together with the rest of the mechanics Lab setup: it is the same used for the Pre-
Breadboard. Ready in OAPD lab.
Breadboard integration is expected to start at the beginning of April
TOU Bradboard test
Preliminary discussions with the industry have outlined this strategy for the TOU prototype test:
Warm test (Research institutes): being the alignment performed in warm conditions, a few test on the expected TOU “warm performance” are foreseen:
1) a test of the PSF optical quality on axis 2) an interferometric test of the TOU optical quality
Cold test (Research institutes + Industry): in a climate chamber operating in vacuum at the required temperature (-80º), we will perform:
3) a test of the PSF optical quality on axis 4) a Hartmann optical quality test
1) TOU PSF Test on axis in warm
Vis Illuminator
Optical FiberOff Axis Parabola
Collimated Beam
Tip-Tilting Flat Folding Mirror
Test Camera, adjustablein focus
Performed by the Research InstitutesPerformed by the Research Institutes
2) TOU Optical Quality Test in warm
Zygo GPI FPZygo GPI FP
F/1.5 Transmission Sphere 4" - 1/10 Wave, P-VDYNAFLECT Coated
Performed by the Research InstitutesPerformed by the Research Institutes
…”in cold” Test selection…
Problems due to the low testing T and to the gradient between inside and outside the Climate Chamber: The input optical window of the Climate Chamber is
affected by aberrations (“lens” effect) – Better to have collimated input beams
If the test requires auxiliary optical components inside the chamber, they will also be affected by aberrations and particular care shall be given to their mounts - Better not to use additional optics and minimize the number of mechanics inside the climate chamber
Robustness to sub-optimal projection systems - rely on centroiding spots other than on size/shape of these
3) TOU PSF Test on axis in cold Performed by the Research Institutes + IndustryPerformed by the Research Institutes + Industry
Vis Illuminator
Optical Fiber
Off Axis Parabola
Collimated Beam
Flat Folding Mirror
Test Camera remotelyadjustable in focus
Climate Chamber (T~-80º)
Input optical window
Advantages:Advantages:- Parallel beam in inputParallel beam in input- No other Optical Parts No other Optical Parts inside the chamberinside the chamber- Only 1 motorized axis in Only 1 motorized axis in coldcold
4) TOU Hartmann test in cold
If the relative position of P1 and P2 is known with anhigh accuracy (linear If the relative position of P1 and P2 is known with anhigh accuracy (linear stage with encoder), we can verify the optical quality in term of Encircled stage with encoder), we can verify the optical quality in term of Encircled Energy, even without going with the CCD there!Energy, even without going with the CCD there!
Advantages:Advantages:- Parallel beam in inputParallel beam in input- No other Optical Parts No other Optical Parts inside the chamberinside the chamber- Only 1 motorized axis in Only 1 motorized axis in coldcold
Performed by the Research Institutes + IndustryPerformed by the Research Institutes + Industry
Vis Illuminator
Optical Fiber
Collimated Beam
Off Axis Parabola
Hartmann Mask
Climate Chamber
Input optical window
CCD (movablein focus)
P1 P2
T~-80º
Procurement Status
The procurement of all the opto-mechanical components needed for the Pre-BB, for the BB, for the lab setup, for the “warm” and “cold” test has started and all the order have been placed since mid November 2010
The opto-mechanical components needed for the Pre-BB have been all delivered
The industrial studies concerning the feasibility of the aspherical lens and the AIV strategy for the 32 telescopes have been placed (Selex Galileo, Medialario, Fisba, RUAG Space)
The order of 2 CaF2 blanks have been placed 2 weeks ago (4 weeks delivery time from Korth Kristalle)
The industrial study on the AlBeMet Structure feasibility has been placed (APCO Technologies)
Time planning
Pre-Breadboard Alignment test results by end of this week
TOU Breadboard Opto-Mechanical and test components arriving by 31
Mar 2011 “Warm” alignment and test of the TOU prototype by
15 Apr 2011 “Cold” test in Galileo by 25 Apr 2011 Test report by 30 Apr 2011
This planning has no contingency present and it is based on the best effort delivery date of SESO
…toward Implementation Phase… Selex Galileo has been associated to the definition of the AIV
procedure and to the BB test in cold, in view of taking over the responsibility during the implementation phase
The date and conditions of the responsibility transfer to industry is under discussion at the moment, starting with the transfer of mechanical design (discussed with both Daniele Piazza and Selex Galileo)
The list of test to be performed on the TOUs during the Implementation Phase is under discussion
Galileo will propose a test strategy and planning for the definition phase, starting on the base of the first preliminary plan outlined at the beginning of the project: Each unit:
▪ thermal cycling ▪ vibration ▪ interferometric optical quality test ▪ focal plane position with respect to a TBD interface plane
One unit every 5 TOUs:▪ Optical quality test in terms of PSF variation over the FoV in flight conditions
The end
miCos positioner PLS-85