Characterization of a Longwave HgCdTe GeoSnap Detector

Rory Bowens; Michael R. Meyer; Taylor L. Tobin; Eric Viges; Dennis Hart; John Monnier; Jarron Leisenring; Derek Ives; Roy van Boekel

arXiv · 2405.20440

Characterization of a Longwave HgCdTe GeoSnap Detector

Rory Bowens·Michael R. Meyer·Taylor L. Tobin·Eric Viges·Dennis Hart·John Monnier·Jarron Leisenring·Derek Ives·Roy van Boekel

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Abstract

New longwave HgCdTe detectors are critical to upcoming plans for ground-based infrared astronomy. These detectors, with fast-readouts and deep well-depths, will be key components of extremely large telescope instruments and therefore must be well understood prior to deployment. We analyze one such HgCdTe detector, a Teledyne Imaging Sensors GeoSnap, at the University of Michigan. We find that the properties of the GeoSnap are consistent with expectations from analysis of past devices. The GeoSnap has a well-depth of 2.75 million electrons per pixel, a read noise of 360 e-/pix, and a dark current of 330,000 e-/s/pix at 45 K. The device experiences 1/f noise which can be mitigated relative to half-well shot noise with modest frequency image differencing. The GeoSnap's quantum efficiency is calculated to be 79.7 +- 8.3 % at 10.6 microns. Although the GeoSnap's bad pixel fraction, on the order of 3%, is consistent with other GeoSnap devices, close to a third of the bad pixels in this detector are clustered in a series of 31 "leopard" spots spread across the detector plane. We report these properties and identify additional analyses that will be performed on future GeoSnap detectors.

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Rory Bowens, Michael R. Meyer, Taylor L. Tobin, Eric Viges, Dennis Hart, John Monnier, Jarron Leisenring, Derek Ives, Roy van Boekel. 2024-05-30. Characterization of a Longwave HgCdTe GeoSnap Detector. https://arxiv.org/abs/2405.20440

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