ACIS Instrument Support - Monthly Progress Report for October 2014

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).

  ...  Continued work on a paper combining CTI, FWHM and background monitoring results from ACIS and Suzaku.  Editing and trying to improve statistics.

  ...  Presented ACIS status at Chandra Quarterly.

  ...  Submitted abstract for "Fifteen years of Chandra" meeting in November on "Fifteen years of the Advanced CCD Imaging Spectrometer".


2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance.  Engineering housekeeping remains nominal.

  ...  Began study of potential future ACIS boot problem.  The EEPROM devices that contain the boot code for the ACIS digital processers are well beyond their specified data retention period.  While they current show no signs of failing, the ACIS team is determining an operation strategy for monitoring EEPROM health and a decision tree for mitigation efforts if problems are found (ftp://acis.mit.edu/pub/acis-eeprom-utils-v1.3.pdf).

  ...  Ran a second test of Detector Housing Heater which has been turned off since 2008.  Heater was turned on for an entire orbit over a range of pitch angles.  The heater performed as expected. At pitch angles of 60 and 90 degrees, the focal plane temperature remained cold.  This data will be used to begin recalibrating the focal plane temperature model with the heater on.

  ...  Reviewed updated contingency SOP for switching from BEP A to BEP B.  (http://cxc.cfa.harvard.edu/acis/acis_command_sequences.html ; 5.8_V2.1 Switch from BEP A to BEP B)

  ...  Participated in analysis and diagnosis of ACIS anomaly during Chandra simulation.

2.2 Flight software maintenance

  ...  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 meetings.  Discussed the results of the second test of the DH heater.  Planning third test with different pitch angles.  Discussed path towards a decision on whether to permanent turn the DH heater back on, and follow up observations afterwards to monitor the response of the contaminant.  Discussed new memo on EEPROM lifetime and future response to any degradation.

  ...  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).

  ...  Reviewed proposed documentation on anomalous short-timescale gain changes on I0 and I2 (not a new problem, just new documentation).
 
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 updates to the Proposers Observatory Guide.

  ...  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.