Proton irradiation results for long-wave HgCdTe infrared detector arrays for Near-Earth Object Camera

Meghan L. Dorn, Judith L. Pipher, Craig McMurtry, Spencer Hartman, Amy Mainzer, Mark McKelvey, Robert McMurray, David Chevara, Joshua Rosser

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


HgCdTe detector arrays with a cutoff wavelength of ∼10 μm intended for the Near-Earth Object Camera (NEOCam) space mission were subjected to proton-beam irradiation at the University of California Davis Crocker Nuclear Laboratory. Three arrays were tested - one with 800-μm substrate intact, one with 30-μm substrate, and one completely substrate-removed. The CdZnTe substrate, on which the HgCdTe detector is grown, has been shown to produce luminescence in shorter wave HgCdTe arrays that causes an elevated signal in nonhit pixels when subjected to proton irradiation. This testing was conducted to ascertain whether or not full substrate removal is necessary. At the dark level of the dewar, we detect no luminescence in nonhit pixels during proton testing for both the substrate-removed detector array and the array with 30-μm substrate. The detector array with full 800-μm substrate exhibited substantial photocurrent for a flux of 103 protons/cm2 s at a beam energy of 18.1 MeV (∼750 e-/s) and 34.4 MeV (∼65 e-/s). For the integrated space-like ambient proton flux level measured by the Spitzer Space Telescope, the luminescence would be well below the NEOCam dark current requirement of <200 e-/s, but the pattern of luminescence could be problematic, possibly complicating calibration.

Original languageEnglish (US)
Article number036002
JournalJournal of Astronomical Telescopes, Instruments, and Systems
Issue number3
StatePublished - Jul 1 2016
Externally publishedYes


  • detector array
  • infrared
  • infrared detectors

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Control and Systems Engineering
  • Instrumentation
  • Astronomy and Astrophysics
  • Mechanical Engineering
  • Space and Planetary Science


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