ACIS Instrument Support - Monthly Progress Report for July 2008

1.  ACIS Characterization

1.1 Characterize and model radiation damage in ACIS CCDs

  ...  Continued work on irradiation/annealing tests done at GSFC
in 2005.  Examined trailing pixel distribution.

  ...  Executed new SI modes which allow more grades to be 
telmetered.  These SI modes are being used to compare TE and CC 
mode grade rejection to help calibrate CC mode.  Four ObsIDs 
(57721, 57694, 57684, 57675) in July.

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)


2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance. 
Engineering status remains normal as we continue operation with the  
Detector Housing heater disabled.

  ...  Performed thermal test with the SIM FA6 heater off.  There was
little to no improvement in thermal control, however there was also
significant Earth in the ACIS radiator field of view.  Future tests 
are being considered.

2.2 Flight software maintenance

2.3 Instrument science performance

  ...  Continued close monitoring of ACIS focal plane 
temperatures.

  ...  Participated in monthly ACIS operations meetings.  Discussed
focal plane temperatures and ACIS support for a planned backup OCC.

  ...  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 questions about ACIS CTI correction calibration.

  ...  Provided ACIS CCD QE with and without an optical blocking filter
for planning a future mission.

  ...  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.  
Reported on improvement in focal plane temperature control since 
turning off the Detector Housing heaters.

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


4.  OCC Support

4.1 Use of MIT/ACIS EGSE at OCC

  ...  Discussed plans for a backup OCC at Cambridge Discovery Park
and different levels of support the ACIS team could provide.

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

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


Outreach:

Mentor to high school students participating in the Chandra
Astrophysics Institute (C. Grant)

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