Instrumentation

I have spent much of my time at UF learning the ins and outs of astronomical instrumentation. I’ve spent months and years working on CIRCE (a near infrared instrument) in the lab at UF and at the Gran Telescopio Canarias in Spain, racking up over 6 weeks at the summit thus far. Most of my time with CIRCE has been hands-on. In addition, I’ve also learned how to design instruments using ZEMAX and SolidWorks for optics and opto-mechanical design work, respectively. (links go to the respective websites)

The GTC is currently the largest steerable telescope in the world, being precisely 10 centimeters larger than both Keck telescopes. It is 10.4 m in diameter.

Here’s a list of my hands-on experience with CIRCE (work overseen by Dr Nick Raines and Prof Steve Eikenberry, as well as Greg Bennett (mechanical engineer) and Scott Mullen (electrical engineer) and other CIRCE team members):

  • Assembly, testing, trouble-shooting of cryogenic mechanisms (eg, filter wheels, mask holders) at both room temp/pressure and cryogenic conditions
  • Assisted in final assembly of the instrument and construction of the thermal shielding (including about a month spent wrapping everything in aluminized Mylar)
  • Built electrical cables that run from the Dewar through the cable chain to the electronics rack (~2 km of wires stretched end to end)
  • Packed (and then unpacked once at GTC) the instrument on its handling cart, the electronics rack, and associated tools
  • Scientific commissioning of CIRCE on-sky in March 2015 (6 half-nights of observing), including:
    • Troubleshot electrical issues in our motor controller box (rewired the box with oversight from our electrical engineer)
    • Worked with UF CIRCE Team + GTC staff to install new environmental cover (necessitated pulling CIRCE off of the telescope and reinstalling it)
    • Planned observations of relevant scientific targets
    • Near real-time data reduction of commissioning data using superFATBOY data pipeline (first beta test)
  • Refurbished CIRCE in March 2016 with Prof Steve Eikenberry and Mr Alan Garner
    • Replaced the half-wave plate polarizer mechanism with one designed by Mr Yigit Dallilar
    • Replaced the slit and polarimetry mask
    • Added grisms borrowed from the FLAMINGOS-1 instrument, giving CIRCE low-resolution spectroscopic capabilities
    • Added new narrowband filters from FLAMINGOS-1 (JH and HK filters) and others
    • 1/2 night of engineering/scientific commissioning to verify instrument performance and spectroscopy mode
  • Passed the machine shop course offered at UF (basic milling, lathe)

Other hands-on tasks have involved:

  • Lab work with SPIFFI, a speckle-stabilized imaging experiment (funding for the next-generation version (the Speckle Stabilized Science Demonstrator) although approved, was not forthcoming)
    • I worked with Dr Mark Keremedjiev to better characterize the ringing of the Fast Steering Mirror and get hands-on experience with the instrument
  • 3D printing and rapid prototyping using our Makerbot Replicator 2 and 2X printers
  • Testing of MIRADAS probe arms (open air testing and cryogenic)
  • Assisted Ms Amanda Townsend in setting up telescopes for her thesis project, a distributed light-gathering telescope made up of 4 smaller telescopes
  • Assisted with printing and commissioning Pepito, a pathfinder spectrograph designed for 3D printing (as opposed to traditional machined components)

 

I also have a lot of design work experience with a handful of instruments.

MIRADAS (also destined to be put on the GTC) is the main instrument for which I’ve done design work. I’ve designed the macro-slicer. If you’re curious, here’s a link to a page with another link to the paper. It’s a bit of a slog, but only 15 pages with figures (lots of those!) and references. I’ve also worked on FRIDA, an imaging spectrograph for GTC, and IGIS (web page coming, TBD).

Here’s a list of my design experience.

  • MIRADAS macro-slicer:
    • optical design using ZEMAX: 36 slitlets sharing 18 pupil mirrors, 12 beam combiner mirrors, and 6 slicer mirrors
    • opto-mechanical design using SolidWorks
      • includes precision location dowel pinholes for repeatable mechanical location (‘automatic’ optical alignment)
      • includes tool marks from machining mirrors
    • 3D printed full-size components
  • IGIS (Integrated Grating Image Slicer):
    • optical design in ZEMAX of 10 slices and 10 pupil mirrors (each with their grating etched into the pupil mirror)
    • optomechanical design in SolidWorks of mirrors, mirror mounts, optical bench and enclosure.
    • Fabrication completed in December 2016 by Durham Precision Optics, to be delivered to UF by February 2016 for further laboratory testing
Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s