ACIS Instrument Support - Monthly Progress Report for September 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.

  ...  Continued study of the time evolution of CTI temperature-dependence.  Temperature-dependent coefficient has changed for parallel CTI on BI CCDs while FI CCDs appear to be unchanged.  Uncovered other potential issues in spatial-structure and energy-dependence of CTI correction.  Results and plan for CALDB improvements presented at ACIS calibration meeting Sept 3.

  ...  Collecting materials and preparing for the upcoming Chandra Quarterly in October.

2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance.  Flight engineering parameters remain nominal.

  ...  Ran test of Detector Housing Heater which has been turned off since 2008.  Heater was commanded on by CAP and left on for ~20 hours.  The heater performed as expected and identically to that observed earlier in the mission.  The focal plane temperature rose from the nominal set point of -119.7C to -117.4C.  A future test is under discussion which would confirm that the focal plane can be kept cold under more favorable conditions.

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 test of the DH heater. Considering second test with more favorable pitch angle to confirm that focal plane can still be kept cold.  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.

  ...  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

  ...  Investigated user question on spatial structure seen in his event data.  Confirmed that it does not correspond to features in the bias map, or in the CCD hardware.  Likely a real extended source.

  ...  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 plans for improving the temperature-dependent CTI correction.

  ...  Participated in telecon for IACHEC Heritage Working Group which has been formed to promote the transmission of expertise, good practice, and calibration-related methods from operational missions to missions under development.

  ...  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.