ACIS Instrument Support - Monthly Progress Report for January 2015

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. (http://space.mit.edu/~cgrant/monitor.html).

  ...  Analyzed new raw frames, posted at http://space.mit.edu/home/fergason/acis/raw.html

  ...  Discussions/review of CXC Cal study of how line energy and width changes with time and temperature.  Continuing to teview FWHM results.

  ...  Began analysis of light leak observations of Betelgeuse.  Raw mode data taken with dither off in 2000, 2005 and late 2014.  Trying to understand if decrease in optical/IR flux can be explained by increasing contamination.


2.  Engineering

2.1 Instrument hardware engineering performance

  ...  On January 11, it was discovered that the ACIS DPA side A was unexpectedly powered off.  The ACIS team has concluded that this was due to an SEU in the ACIS PSMC.  Similar events are documented in Flight Notes 394 and 417.  Supported anomaly investigation and analysis.  Reviewed recovery CAP 1342 (http://acis.mit.edu/asc/cap/CAP1342.pdf).  More information on the anomaly and the team's response can be found in Flight Note 563.

  ...  Continue to monitor long term ACIS instrument performance.  Engineering housekeeping remains as-expected.

  ...  Reviewed updated version of contingency SOP for switching from BEP A to BEP B.  Waiting to test on ACIS engineering unit.  (http://cxc.cfa.harvard.edu/acis/acis_command_sequences.html ; 5.9_V2.1 Switch from BEP A to BEP B)

  ...  Reviewed draft of the SOT SOP for DEA and FEP diagnostic procedures.  Written in response to the HiLo Pixel Anomaly.

2.2 Flight software maintenance

  ...  Discovered problem with ACIS Engineering Unit PSMC.  Working to find and test a repair strategy in February.

  ...  Flight software patch F-G-H (improved buscrash2) uploaded in June and has continued to run with no issues.

2.3 Instrument science performance

  ...  Participated in monthly ACIS operations meeting.  Discussed DPA-A anomaly, radiation events around Christmastime, engineering unit status, light leak observations and new CTI-radiation models.

  ...  Participated in radiation working group telecons.  Reviewed CXC models of CTI trends using various measures of particle rates.  Answered questions on CCDs and radiation damage.  Model may be used to evaluate the effectiveness of limiting ACE P3 fluence.

  ...  Recommended CCD combinations for ready-to-run ECS measurements when thermal conditions require fewer CCDs.

  ...  Co-author on a abstract submitted to the summer SPIE meeting, "Modeling contamination migratino on the Chandra X-ray Observatory III"

  ...  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 ACIS response discussion group.  Discussion included low energy gain on S1 and S3, contamination monitoring, and CC mode analysis.

  ...  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.