Chandra X-Ray Observatory
Last modified: 7 September 2018

FI: Frontside Illuminated

A CCD chip (on ACIS) in which X-rays are incident on the gate structure on the front of the chip. This blocks some low energy X-rays, but has lower background and (in the absence of parallel CTI) provides better energy resolution than BI (backside illuminated) chips.

See the ACIS entry for more details on the CCD chips.

Last modified: 7 September 2018
Smithsonian Institute Smithsonian Institute

The Chandra X-Ray Center (CXC) is operated for NASA by the Smithsonian Astrophysical Observatory. 60 Garden Street, Cambridge, MA 02138 USA.   Email: Smithsonian Institution, Copyright © 1998-2017. All rights reserved.