ACIS Instrument Support - Monthly Progress Report for May 2012

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,
  spectral line centroid and width, and focal plane temperature.
  Updated monitoring web pages.  Small improvements made in web page
  text and treatment of leap years.
  (http://space.mit.edu/~cgrant/monitor.html)

  ...  Continued work on a paper combining CTI, FWHM and background
  monitoring results from ACIS and Suzaku.  Continued writing text for
  nearly completed A&A paper.  Trying to better quantify the amount of
  sacrificial charge from the particle background and how it changes
  between XIS and ACIS.

  ...  Examined whether current ECS count rate is low enough to allow
  additional event grades to be telemetered.  Accepting all grades
  except for g255 should not saturate telemetry.  A new set of CTI SI
  modes is being prepared to allow more grades to be telemetered
  during CTI observations.


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

  ...  Participated in monthly ACIS operations meeting.  Topics
  included the May 29 safe mode, the status of the TXINGs patch, the
  change to grade selection for ECS measurements and thermal issues.

  ...  Continued work optimizing the parameters for the TXINGS patch.
  Reported on verification of the new ACIS TXINGS parameters at FDB
  meeting on 17 May.  TXINGS patch now running with optimal
  parameters.  Changing particle background will require revisiting
  the parameters occasionally.

  ...  TXINGS patch correctly signaled a high radiation environment on
  17 May, shortly before SCS107 was triggered.

  ...  Chandra OBC patched on May 30.  The next ACIS TXINGS trigger
  should be acted upon by the spacecraft, so ACIS can now hide itself
  during times of high radiation.

  ...  Two proceedings papers on the TXINGS patch are being prepared
  for the upcoming SPIE meeting.

  ...  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).

3.2 Provide data analysis support

  ...  Participated in CXC Cal/Ops modeling discussion group.
  Discussed CC mode calibration (nearly finished), contamination
  measurements, and gain issues at low energies on S1.

  ...  Supported an SDS-led meeting on single frame overclock
  anomalies and the best method of finding and fixing them.

  ...  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.



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