Because the HETG illuminates regions of the ACIS-S FI CCDs with essentially monochromatic, known energy X-rays, HETG data can be used to measure parallel CTI values. Three methods/examples are illustrated here.
Some preliminary results for Day 258 conditions:
- S1 CTI at 0.8 to 1.0 keV is ~ 1.5 x 10-4
- S0,S2,S4,S5 CTI is energy dependant with values:
- 0.8 to 1.0 kev ~ 5.7 x 10-4
- 1.3 to 1.5 kev ~ 3.6 x 10-4
- dE/E due to CTI ~ 1.7 / (CTI x CHIPY)
(in 0.8-1.0 keV range for FIs on ACIS-S)