Charge Diffusion Variations in Pan-STARRS\,1 CCDs
Abstract
Thick back-illuminated deep-depletion CCDs have superior quantum efficiency over previous generations of thinned and traditional thick CCDs. As a result, they are being used for wide-field imaging cameras in several major projects. We use observations from the Pan-STARRS survey to characterize the behavior of the deep-depletion devices used in the Pan-STARRS1 Gigapixel Camera. We have identified systematic spatial variations in the photometric measurements and stellar profiles which are similar in pattern to the so-called "tree rings" identified in devices used by other wide-field cameras (e.g., DECam and Hypersuprime Camera). The tree-ring features identified in these other cameras result from lateral electric fields which displace the electrons as they are transported in the silicon to the pixel location. In contrast, we show that the photometric and morphological modifications observed in the GPC1 detectors are caused by variations in the vertical charge transportation rate and resulting charge diffusion variations.
Cite
@article{arxiv.1710.01819,
title = {Charge Diffusion Variations in Pan-STARRS\,1 CCDs},
author = {Eugene A. Magnier and J. L. Tonry and D. Finkbeiner and E. Schlafly and W. S. Burgett and K. C. Chambers and H. A. Flewelling and K. W. Hodapp and N. Kaiser and R. -P. Kudritzki and N. Metcalfe and R. J. Wainscoat and C. Z. Waters},
journal= {arXiv preprint arXiv:1710.01819},
year = {2018}
}
Comments
submitted to PASP