...
- Measuring CTI, ACIS vs XIS (methodology)
- ACIS – fit all grades, only center pixel pulseheight vs ccdy/ccdx (binning/fitting details needed)
- XIS – fit only good grades, summed pulseheight from top cal source corners
- process ACIS the same way as XIS for comparison? only use center pixels? CTI metric to be decided
- only use Mn K alpha
- include
checker-flag CTI measurement for XIS, SCI-off (Ozawa 2009)
- CTI evolution, plots of measured CTI vs time
- for ACIS, apply corrections for temperature and sacrificial charge
- not done for XIS; temperature is stable, background is integrated over 1 day = 16 orbits
- decide on time binning
- not necessary to be the same for ACIS/XIS, and might be misleading given very different cal source duty cycles
- compare differences in rate of CTI increase (and shape?)
- (no parallel vs serial)
- FI vs BI
- low vs high orbit
- with and without CI (for XIS, when possible)
(insert additions to this list here)
- charge trailing vs time
- trailing fraction shows how initial ACIS from low energy protons is different from ongoing, higher energy particle damage
- metric is average lost charge of all events divided by average trailed charge of all events
...
- relate CTI/FWHM increase to measures of particle fluence, particle type
- maybe beyond scope of this paper)
- comparison of a celestial source
- E0102
- has been observed extensively over time with ACIS and XIS
- low energy lines very different from Mn K alpha
- mostly on ACIS-S3
- Perseus, other clusters
- check ACIS time coverage, XIS and ACIS roll angles
- Fe line centroid changes with kT, location in cluster
- E0102