FPFPU Alignment 1

PACS IIDR 01/02 Mar 2001

FPFPU Alignment

D. KampfKAYSER-THREDE

FPFPU Alignment 2

PACS IIDR 01/02 Mar 2001

Subsystem declaration

• Top Optics common entrance optics• Photometer red and blue bolometer arrays• Slicer slicer and slicer optics• Collimator collimator mirrors and

grating• Spectrometer red and blue spectrometer

arrays

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PACS IIDR 01/02 Mar 2001

Mechanical Subsystems

• Top Optics• Photometer support, mounted to top optics

• Bolometer, fixed to bolometer support• Collimator, contains collimator, grating, slicer

and slicer optics, fixed to top optics and spectrometer

• Spectrometer, base plate for spectrometer detectors, spectrometer optics and top optics

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Top Optics

•10 mirrors (4 flat)

•real field stop to real field stop

•real pupil as aperture stop

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Top Optics•Optomechanical layout

•entrance compartment up to aperture stop

•exit compartment up to intermediate focal plane

•entrance and exit layers are on different mechanical layer

•no direct straylight path

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Photometer

•Red and blue bolometer

•common Field Mirror

•Dichroic for beam splitting

•7 mirrors (2 flat)

•pupil stop in front of each bolometer array

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Photometer

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PACS IIDR 01/02 Mar 2001

Slicer

• to slicer optics (4 mirrors)

•slicer (3*5 mirrors)

•Field mirrors are entrance to collimator

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PACS IIDR 01/02 Mar 2001

Collimator•2 collimator mirrors

•1 grating

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Spectrometer

•Red and blue spectrometer channel

•dichroic for channel splitting

•exit of collimator between periscope 1 & 2

•7 mirrors (3 flat)

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Alignment TaskSUBUNI T ALI GNMENT TASK

Top optics

Telescope f ocal plane (point source)->

aperture stop (autocollimation) ->

chopper (autocollimation)->

common focal plane of bolometer andspectrometer

Photometer optics

Common focal plane (point source)->

dichroic_b ->

photometer pupil (fi lter) ->

focal planes (red & blue)

Slicer optics Common focal plane (point source)->

slicer entrance (focus)

Slicer Slicer entrance (f ocus, point source) ->

collimator entrance (f ocus)

Collimator

Collimator entrance (f ocus, point source) ->

grating (pupil, autocollimation) ->

collimator exit (focus)

Spectrometer optics

Spectrometer entrance (f ocus, pointsource) ->

dichroic_s ->

spectrometer pupil (fi lter) ->

focal planes (red & blue)

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PACS IIDR 01/02 Mar 2001

Top optics alignment

Collimated laser at centre of telescope secondary

Masks on TROG 1 -3 and FOLD 1

FPFPU Alignment 13

PACS IIDR 01/02 Mar 2001

Top optics alignment

Scatter plate at aperture stop together with CCD for FOLD 1 alignment ( 4 point sources at the edge of the telescope secondary)

FPFPU Alignment 14

PACS IIDR 01/02 Mar 2001

Top optics alignment

Point source array at chopper location and scatter plates with CCD at telescope secondary mirror edge position (alignment of FOLD 2 and FOLD 3)

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PACS IIDR 01/02 Mar 2001

Top optics alignment

Point sources at focal plane of top optics. Mask at photometers Field mirror for pupil alignment. Alignment of FOLD 4 and FOLD 5 using scatter plates at secondary mirror

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Photometer alignment

Centering of photometer mirrors using laser beam with predefined path from top optics focal plane and field mirror centre.

Position of pupils at the bolometer entrance is predefined (mechanically)

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PACS IIDR 01/02 Mar 2001

Photometer alignment

Point sources at the focal plane of the top optics.

Check pupil between Dichroic and PERI 1, also at pupil to bolometer array

Red channel alignment without dichroic

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PACS IIDR 01/02 Mar 2001

Slicer optics alignment

Focus to focus alignment with real pupil between IMAGE 1 and IMAGE 2.

Point source array at nominal focalplane of Top optics for realization. Scatter plate at slicer entrance

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PACS IIDR 01/02 Mar 2001

Slicer optics alignment

Slicer mirror stacks are prealigned before slicer alignment (laser at translation and rotary stage)

Focus to focus alignment with pupil at SLICER REIMAGE

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PACS IIDR 01/02 Mar 2001

Collimator alignment

Collimator alignment by means of autocollimation mirror at the grating position

Focus to focus alignment. Point source slit arrangement to scatter plate at nominal focus of collimator (with CCD visualisation)

Grating alignment by means of rotation and measuring the high orders reflected light in the collimators focal plane (always at the same position, otherwise alignment of the grating)

FPFPU Alignment 21

PACS IIDR 01/02 Mar 2001

Spectrometer alignment

Focus to focus alignment with two stages (intermediate scatter plate between MIRROR 2 & 3)

Scatter plate at the detector position, point sources at the nominal focal plane

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FPU Alignment to Telescope

Optical Parameter

Primary mirror:

radius of curvature: 3500 mm

conic constant -1.001

Vertex Primary to vertex secondary: 1587.97 mm

Secondary mirror:

Radius of curvature 345.26 mm

Conic constant -1.292180

Diameter 308.32 mm

Distance vertex of secondary to focal plane: 2637.97 mm

Distance focal plane to OB (on axis) 202 mm

FPFPU FOV 0.13569915 deg - 0.18595779 deg.

+/- 0.03216578 deg.

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Optical Tolerances

• Optimized system distorted with random deviationsrealigned focal position: 8 mm

Toleranced mirrors for the blue photometer

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Optical Tolerances

– spherical and toroidal mirrors radius: +/- 1 %tilt: +/- 0.1 deg.

decenter: +/- 1 mmaxial shift: +/- 1 mm

– off axis aspheres and toroids radius: +/- 0.5%cc +/- 5%

tilt: +/- 0.05 deg.decenter: +/- 0.5 mm

axial shift: +/- 0.7 mm

– decenter and tilt tolerances appear in combination and will be readjusted. – The alignment procedure will contain a complete tolerancing for each mirror

installed. Flat mirrors are not taken into account as they will be used for axis realignment.

– No showstopper could be identified.

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FPU Alignment to Telescope

Alignment mirror location (+/- 0.5 mm for feet location and +/- 1 mm for alignment mirrors)

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PACS IIDR 01/02 Mar 2001

AKF position for FPU alignment at Optical Bench (+/- 1 mm or +/- 2 arcmin)

Combined error for position (+/- 2.5 mm) and measurement (+/- 1.5 mm)

delta = 5 arcmin (maximum)

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OGSEOGSE

For alignment purpose following OGSE will be used:

1. 4 x CCD array with optics

2. PC with f ramegrabber

3. 2 x alignment telescope

4. 4 x HeNe Laser (laser diode)

5. Set of pinholes f rom nickel with LED's (point sources)

6. Support structure for pinholes

7. Masks for mirrors (plexiglas with 3 point orientation to the f ront surface)

8. Scatter-plates

9. Lateral translation stages

10. 2 x Rotary table

11. Alignment mirrors during alignment (temporary)

Alignment mirrors for FPFPU alignment