ACIS Instrument Support - Monthly Progress Report for February 2008

1.  ACIS Characterization

1.1 Characterize and model radiation damage in ACIS CCDs

  ...  Continued work on a paper presenting the results of the 
radiation damage/reverse annealing tests done at GSFC in 2005.

  ...  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
(57982, 57968, 57954, 57939) in February.

  ...  Began investigating differences in continuous clocking
performance as compared to the standard timed-event mode.

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)

  ...  Presented ACIS instrument status at ACIS team meeting in 
State College, PA.

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

  ...  Worked with PSU to implement temperature-dependent CTI
correction into their CTI corrector.

1.7 Produce novel data products from the MIT ACIS database

  ...  Provided information on instrument configuration during
XRCF tests.


2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance.
A review of ACIS engineering data shows all parameters running within  
expected limits.  The instrument continues to operate nominally.

  ... Three Detector Housing cooling tests were conducted in February
during perigee passages.  Results were consistent with thermal models.
Indications are that the survival heater (correctly) maintained the 
temperature above -71.1C during the final test.

  ...  Reviewed and approved new proposed yellow upper limits on 
instrument temperatures

2.3 Instrument science performance

  ... Participated in monthly ACIS operations meetings.  Discussed
detector housing cooling tests and other thermal issues.

  ...  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).

  ...  Answered questions about the spatial and spectral properties
of ACIS contamination and provided data analysis help.

3.2 Provide data analysis support

  ...  Provided figures and text summarizing ACIS instrument status 
and ACIS team activities for the Chandra Senior Review.

  ...  Participated in CXC Cal/Ops modeling discussion group.

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

  ...  Participated in discussions of cosmic ray afterglow properties 
and parameters for their detection.

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:

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