TripleSpec: A Union of Engineering and Infrared Astronomy

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TripleSpecA Union of Engineering and Infrared
Astronomy
NASA/IPAC/R. Hurt

• Angie Wolfgang
• James Lloyd
• Astronomy Department
• Cornell University

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What is TripleSpec?
A spectrometer . . .
Visible 0.4µm to 0.7µm TripleSpec 0.8µm to 2.5µm
that separates wavelengths of near-infrared light
. . .
which was emitted by faint sources

• small, cool stars

• brown dwarfs

NASA/ESA/G. Bacon
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What do we hope to find?
Exoplanets!

• To date, only 250 detected
• Most are gas giants like Jupiter
• Smaller star, fainter signal . . . more
  Earth-like planet?

? Radial Velocity
? Mass and Orbit of Planet
Doppler Shift
How?
Center of Mass
?shift ?o(1vrad/c)
b
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Now to the engineering
Optics!
How do we separate the wavelengths?

• mirrors
• prisms
• diffraction grating
• lenses

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More engineering
The detector

• measures intensity of light at different
  wavelengths
• wavelengths mapped out in pattern across array

Prism dispersion
Cross-dispersed!
Grating dispersion
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To put it all together
Mechanical design
Bulkheads

• infrared wavelengths ? a lot of noise from heat
  h
• protect the optics!
• structural support
• still worried about heat . . .

? optics must be cold!
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Reduce thermal radiation
Need insulated layers!
Vacuum!
Outer case
Inner tank with LN2
G10 a poor thermal conductor
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Still reducing radiation
More insulated layers . . .
Mylar

• Black Paint
• absorbs unwanted reflected light
• slowly radiates extra heat into LN2, keeping
  inside cool

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What Ive done . . .
Paint!
Paint
Paint
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What Ive done . . .
Assembly!
Three-bulkhead unit
Auxiliary tank
Prism Box
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What Ive done . . .
Testing!
Laser alignment check
Adhesion of glue at 77 K
Cryogenic performance of thermal fuses
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What Ive done . . .
Wiring!
Routing wires
Learning how to solder
Soldering two heater banks
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Working with hardware
It has been a different . . .
. . . but very rewarding experience!
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Thank You!
NASA New York Space Grant Consortium Erica Miles
Jamie Lloyd Terry Herter Chuck Henderson Steve
Parshley Phil Muirhead
Gustavo Rahmer Marco Bonati Joe Adams Babs Rojas