An IFU slicer spectrometer for SNAP

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An IFU slicer spectrometer for SNAP

• IFU slicer concept
• Compact and light (20x30x10 cm)
• Galaxy and SN spectrum at the same time

IR path
Development in France, Marseille CNRS (IN2P3,INSU
)
Visible IR
Wavelength coverage (?m) 0.35-0.98 0.98-1.70
Field of view 3.0" / 6.0" 3.0" / 6.0"
Spectral resolution, l/dl 70-200 70-100
Spatial resolution element (arc sec) 0.15 0.15
detectors LBL CCD 10 mm HgCdTe 18 mm
Efficiency with OTA and QE gt50 gt40
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Slicer Concept
Slicer Mirror Array
Telescope Focal Plane
Telescope

• Slice image into the telescope focal plane

• Rearrange them along the entrance slit of
  spectro the row of slit mirror

Row of Pupil Mirrors
Row of Slit Mirrors
?
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Simulation
Developed in Marseille in phase with the
instrument
Flatfield
Background
l
1.0
1.8mm
0.8
1.2 mm
Needed to control and validate a precision
0.6
visible
infrared
x,y
PSF parametrised with Shapelet neural network
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RD Spectrometer demonstrator

• A SNAP demonstration spectrometer assembly is
  going on
• Build a complete spectrometer with new slicer
  design and SNAP specifications
• Prove SNAP requirements for spectro-photometric
  performances
• include fabrication and testing
• test both in room T and cold T
• Validate and tune the simulation

detector
spectrometer unit
Well in phase with the SNAP instrument Same
optical design Same characteristics (PSF,
sampling ..) Validation in visible and IR range.
slicer unit
Funded by CNRS (IN2P3/INSU), CNES and Berkeley
university
steering unit
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General design

• Overall dimensions with the IR detector snap
  spectrometer some relay for convenience on the
  detector positioning

420 mm
210 mm
630 mm
650 mm
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RD SNAP Spectrograph demonstrator
Concept done Technical review in Nov
05 Manufacturing started Integration and test for
end 2006
Cold test in a cryostat used currently for
Herschel in LAM
Warm tests in a dedicated clean room
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Demonstrator schedule
2005
2006
Demonstrator design
Demonstrator building
assembly
IR test design and build
Warm test
H1RG test
Cold test
Slicer unit design and build
Steering mirror calibration, build and tests