Instrument Team Monitoring of ACIS

ACIS Monitoring

Radiation Damage Monitoring

Charge transfer inefficiency (CTI) and particle background

Trailing pixel - lost charge re-emitted into a trailing pixel

Instrument Monitoring

Corner pixel distribution

Overclock levels

Focal plane temperature

Calibration Monitoring

Detector gain

Spectral line centroid and width - Gaussian fits at 5.9 and 1.5 keV

Contamination

Detection efficiency - measuring changes at high energy from CTI

Related Pages

Bev LaMarr's images of recent raw frames

ACIS CTI background detrending (major update 11/12/10)

Preliminary analysis of Oct 2003 CTI change (now understood as sacrificial charge from the particle background)

Alternating exposure mode data analysis (was used for removing the FI CCD CTI background dependence, now superceded)

• April 2007 - Temperature filters all updated to better reflect the temperature dependence of each monitored quantity. In most cases, the new temperature filters also increase the total amount of usable data. CTI monitoring is unchanged and uses all available data and applies a temperature-dependent correction. Trailing pixel and spectral line monitoring have the temperature upper limit raised from -119.7 to -119.4. Detector gain and detection efficiency monitoring have the temperature upper limit raised from -119.7 to -119.0. Corner pixel monitoring used to use all available data and now has a temperature upper limit of -119.0.
• September 2008 - Added focal plane temperature page.
• April 2012 - Added overclock levels page.
• Jan 2013 - Completely overhauled line fits.
• Jan 2013 - Switched postscript links to PDF