ACIS Instrument Support - Monthly Progress Report for March 2013

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. Presented poster at HEAD
  meeting.


2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance.
  ACIS continues to perform nominally.

2.2 Flight software maintenance

  ...  Continued analysis of ACIS trickle bias/loss-of-bias anomaly
  from Feb. 17.  Opened problem report SPR148
  (http://acis.mit.edu/axaf/spr/prob0148.html).  Reproduced the
  loss-of-bias anomaly with the Engineering Unit.  Identified a bug in
  the response of the buscrash2 patch to a trickle-bias anomaly that
  caused the loss-of-bias.  buscrash2 patch corrected and tested (ECO
  36-1047).  Meanwhile, existing buscrash2 patch is a reliable
  antidote to trickle-bias anomalies.  (The trickle-bias anomaly
  itself remains tricky and has not been reproduced on the Engineering Unit.)

  ...  Engineering Unit currently running on a reasonably modern
 Solaris workstation.  Testing continues on a Linux CentOS 5
 workstation as an eventual replacement.  Requires changing hardware
 interfaces which is still under test.
 
2.3 Instrument science performance

  ...  Both ACIS and the Chandra OBC are now ready to respond to a
  radiation trigger from the TXINGs patch.  Changing particle
  background will require revisiting the patch parameters a few times
  a year.  Waiting for first ACIS triggered shutdown - one ground
  commanded radiation shutdown in March, ACIS did not trigger.

  ...  Presented poster on ACIS radiation monitoring at HEAD 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

  ...  Attended IACHEC meeting to represent ACIS instrument team.
  Organized CCD working group meeting including cross-mission timing
  mode calibrations, ACIS particle background characterization and
  charge trap modeling.  Also had conversations with eROSITA
  representatives on their radiation protection plans.  Cross-mission
  discussions of contamination calibration.

  ...  Provided guidance to Suzaku XIS team on observing Sco X-1 and
  how ACIS determined it's high count rate limits on observing bright sources.

  ...  Participated in CXC Cal/Ops ACIS response discussion group.
  Discussed contamination, CC-mode calibration and low energy gain
  problems on S1.

  ...  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.  Considering options for replacing broken EGSE
  backup machine.

  ...  Work continues on upgrading TST machines to Solaris and then
  Linux.  EGSE code being ported to Linux.  All daily monitoring s/w
  has been tested on CentOS 5.  Tcl/Tk routines have been rewritten.
  All engineering unit and TST-related software has been tested on
  CentOS 5, except binaries that talk to the EU interface devices.


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