ACIS Instrument Support - Monthly Progress Report for August 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).

  ...  Confirmed that serial CTI on the FI CCDs remains unmeasurable.

  ...  Prepared slides on ACIS status for upcoming Chandra Quarterly 
Review.


2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance. 
ACIS continues to perform nominally.

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.  Discussed
proposed patch and available EPHIN/ACIS data.

  ...  Participated in monthly ACIS operations meeting.  Discussed
SOT recommendations for focal plane temperature regulation and
using ACIS as a radiation monitor.

  ...  Reviewed SOT memo on suggested guidelines for mission planning to
control ACIS focal plane temperatures

  ...  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).

  ...  Investigated odd features in recent S4 data as reported by
a Chandra user.  Initial investigation indicates they may be 
residual streak events and are not a new problem.  Requested
documentation changes to CXC HelpDesk to clarify "destreak" tool.
Continuing to ponder the overlap of bad column assignments and
S4 streak events.

  ...  Provided information on ACIS gain accuracy and stability for 
Astro-H SXI team.

  ... Provided information on ACIS background rates as a function
of spacecraft altitude for a proposed future mission.

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.  Replaced failed disks and verified all is now
OK.


Outreach:

None