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Title: ProtoDESI: First On-Sky Technology Demonstration for the Dark Energy Spectroscopic Instrument

The Dark Energy Spectroscopic Instrument (DESI) is under construction to measure the expansion history of the universe using the baryon acoustic oscillations technique. The spectra of 35 million galaxies and quasars over 14,000 square degrees will be measured during a 5-year survey. A new prime focus corrector for the Mayall telescope at Kitt Peak National Observatory will deliver light to 5,000 individually targeted fiber-fed robotic positioners. The fibers in turn feed ten broadband multi-object spectrographs. We describe the ProtoDESI experiment, that was installed and commissioned on the 4-m Mayall telescope from 2016 August 14 to September 30. ProtoDESI was an on-sky technology demonstration with the goal to reduce technical risks associated with aligning optical fibers with targets using robotic fiber positioners and maintaining the stability required to operate DESI. The ProtoDESI prime focus instrument, consisting of three fiber positioners, illuminated fiducials, and a guide camera, was installed behind the existing Mosaic corrector on the Mayall telescope. A fiber view camera was mounted in the Cassegrain cage of the telescope and provided feedback metrology for positioning the fibers. ProtoDESI also provided a platform for early integration of hardware with the DESI Instrument Control System that controls the subsystems, provides communication withmore » the Telescope Control System, and collects instrument telemetry data. In conclusion, lacking a spectrograph, ProtoDESI monitored the output of the fibers using a fiber photometry camera mounted on the prime focus instrument. ProtoDESI was successful in acquiring targets with the robotically positioned fibers and demonstrated that the DESI guiding requirements can be met.« less
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  1. Univ. of California, Berkeley, CA (United States). Dept. of Physics
  2. National Optical Astronomy Observatory (NOAO), Tuscon, AZ (United States)
  3. The Barcelona Institute of Science and Technology (BIST), Barcelona (Spain). Inst. de Fisica d'Altes Energies (IFAE)
  4. Yale Univ., New Haven, CT (United States). Dept of Astronomy
  5. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
  6. Boston Univ., MA (United States). Dept. of Physics
  7. The Ohio State Univ., Columbus, OH (United States). Dept of Astronomy
  8. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Astronomy
  9. The Ohio State Univ., Columbus, OH (United States). Dept of Astronom
  10. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  11. Univ. of Warwick, Coventry (United States). Dept. of Physics
  12. SLAC National Accelerator Lab., Menlo Park, CA (United States)
  13. Univ. of California, Observatories, Santa Cruz, CA (United States)
  14. Institute of Space Sciences (IEEC-CSIC), Barcelona, (Spain). Institut de Ciencies de l'Espai
Publication Date:
Report Number(s):
arXiv:1710.08875; FERMILAB-PUB-17-496-CD
Journal ID: ISSN 0004-6280; TRN: US1801421
Grant/Contract Number:
AC02-76SF00515; AC02-05CH1123; AST-0950945; 320964; AC02-07CH11359
Accepted Manuscript
Journal Name:
Publications of the Astronomical Society of the Pacific
Additional Journal Information:
Journal Volume: 130; Journal Issue: 984; Journal ID: ISSN 0004-6280
Astronomical Society of the Pacific
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25); National Science Foundation (NSF); United Kingdom Science and Technologies Facilities Council; Gordon and Betty Moore Foundation (GBMF); Heising-Simons Foundation; National Council of Science and Technology of Mexico; European Union (EU)
Country of Publication:
United States
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 79 ASTRONOMY AND ASTROPHYSICS; Dark energy: BAO; Baryon acoustic oscillations; Instrumentation: miscellaneous; Methods: Observational; Telescopes; Galaxies; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1438046