ACIS Instrument Support - Monthly Progress Report for July 2010

1.  ACIS Characterization

1.1 Characterize and model radiation damage in ACIS CCDs

  ...  Continued work on irradiation/annealing tests done at GSFC
in 2005.  Writing up as a paper.

1.3 Monitor scientific on-orbit performance of ACIS

  ...  Continued monitoring of ACIS CTI, gain, trailing pixel 
pulseheight, detector efficiency, corner pixel distribution, spectral 
line centroid and width, and focal plane temperature.  Updated 
monitoring web pages.  (http://space.mit.edu/~cgrant/monitor.html)

  ...  Continued to recalibrate CTI-sacrificial charge correction
used in monitoring.  Quiescent background rates are now trending
downwards as the new solar cycle starts, making recalibration
possible (and necessary).


2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance. 
All engineering parameters remain within normal range save the
well-documented trend of increasing heat load on the focal plane.

2.3 Instrument science performance

  ...  Continued investigation into whether ACIS can act as it's own
radiation monitor, prompted by action from the thermal working group
which is concerned about the continued degradation of EPHIN.  Presented 
initial results at SPIE meeting (arXiv:1007.4185).  Drafted report on
whether it would be practical to develop a patch to ACIS flight software.
Review and discussion ongoing.

  ...  Reviewed SOT memo on ACIS focal plane temperatures and the
correlation with the number of CCDs clocking.

  ...  Participated in radiation working group telecon.

  ...  Continued daily quick-look processing of ACIS telemetry and
maintained Web interface to ACIS real-time data.

  ...  Continued to publish the "annotated DOT" timeline reports.


3.  CXC Support

3.1 Provide user support

  ...  Updated ACIS memo listing calibration ObsIDs and 
observation characteristics (ACIS Memo #165).

3.2 Provide data analysis support

  ...  Participated in CXC Cal/Ops modeling discussion group.  Discussed
status of temperature-dependent CTI correction software and CC-mode 
calibration.

  ...  Continued to maintain ACIS calibration database of ground 
and flight data products.

4.  OCC Support

4.1 Use of MIT/ACIS EGSE at OCC

  ...  Continued support and maintenance of ACIS EGSE software and
hardware at the OCC.


Outreach:

Presentation at SPIE Astronomical Telescopes and Instrumentation 2010
 * Grant et al., "Using ACIS on the Chandra X-ray Observatory as a 
particle radiation monitor"