ACIS Instrument Support - Monthly Progress Report for February 2007

1.  ACIS Characterization

1.3 Monitor scientific on-orbit performance of ACIS

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

  ...  Continued a more comprehensive study of the effect of 
focal plane temperature variations on the metrics used in ACIS
monitoring.  When complete, will be used to define temperature
filter criteria more appropriate to the data.

  ...  Finished work on memo for the operations team on the 
consequences of a future, unprotected radiation belt transit by 
ACIS.  Distributed widely.  (http://space.mit.edu/~cgrant/acis.html 
and http://space.mit.edu/ACIS/iacis.html)

  ...  Presented ACIS status and unprotected ACIS study at ACIS
team meeting in State College, PA.

  ...  Co-author of an abstract submitted for the summer SPIE
meeting on managing Chandra radiation degradation.

  ...  Worked with PSU to update the time-dependent CTI information
in their CTI corrector.


2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance.
The ACIS instrument continues to function nominally.  We note that the
focal plane housing, which is cooled by the warm radiator and controlled
to sit at -60C, is starting to experience cases where its temperature
regulation is marginal.  This is due to the generally deteriorating
condition of the ISIM thermal environment (as opposed to a reduction in
the capabilities of the radiator).

2.2 Flight software maintenance

2.3 Instrument science performance

  ...  Participated in monthly ACIS operations meeting.  
Discussed dropping E1300 as a radiation trigger and PSMC thermal
excursions.

  ...  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.

2.5 Participate in Chandra activities


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.

  ...  Continued to maintain ACIS calibration database of ground 
and flight data products.  Upgraded primary ACIS monitoring
workstation.  Migrated ground testing data from XRCF and LLTV
off of a failing disk. 

  ...  Answered question about spectral features at high energies.
These features are due to single saturated pixels.

  ...  Answered question about anomalous ACIS data containing
events with grade 255 which should be removed on-board.  Events
were all due to a single pixel with a bias parity error. 
Confirmed in ACIS DPA Hardware Spec that behavior is expected.


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.

  ...  Continued work on improving configuration management of 
the ACIS workstations in the TST area of the Chandra OCC.  Work 
nearly complete.


Outreach:

None

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