ACIS Instrument Support - Monthly Progress Report for February 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)

  ...  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 hardware on-orbit continues to function nominally.

  ...  The ACIS Engineering Unit experienced a hardware anomaly in 
Februrary.  Conclusions of the investigation are that the FEP_5 board
board malfunctioned.  Additional anomalies during the investigation
were most likely due to dirty/dusty connectors.  The malfunctioning
board has been replaced by a flight spare and will undergo further 
testing to determine the source of the problem.  The exposed parts 
of the DPA and DEA assemblies are now partially covered to prevent 
further dust/dirt contamination.

2.2 Flight software maintenance

  ...  Testing and documentation of new flight software standard patch 
release E completed.  Prepared and reviewed FDB presentation and draft
SOP.  Will be presented to FDB in mid-March.  This version includes two 
new standard patches, badpix and buscrash2, which address software problem 
reports 141 and 142.

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.  Cross-
checking ACIS and SOT radiation shutdown listings.  Discrepancies are
now understood and are being corrected.  Compiling full mission exposure
record data to test possible triggers.

  ...  Discussed further reducing the radiation belt backoff time from
5 hrs to 4 hrs from perigee.  ACIS team approves.

  ...  Participated in monthly ACIS operations meeting.  Discussed
engineering unit troubles and new flight software patch.

  ...  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

  ...  Answered user question on data analysis problems with measuring
Fe-55 decay in the ACIS calibration source.

  ...  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.

  ...  Reviewed proposed thread web page for running the temperature-
dependent CTI correction algorithm.

  ...  Reviewed poster for upcoming HEAD meeting on the temperature-
dependent CTI correction.

  ...  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:

none this month

all recent memos available at http://space.mit.edu/ACIS/iacis.html