ACIS Instrument Support - Monthly Progress Report for April 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.

  ...  Examined evolution of pulseheight droop in central columns. Change is small, not worrisome, will write up results.

  ...  Prepared and presented slides on ACIS status at the Chandra Quarterly.


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

  ...  Finished analysis of ACIS trickle bias/loss-of-bias anomaly from Feb. 17.  See problem report SPR148 (http://acis.mit.edu/axaf/spr/prob0148.html)  An improved version of the buscrash2 patch has been written, but will not be uploaded until additional patches are necessary.

  ...  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

  ... Participated in monthly ACIS operations meetings.  Discussed radiation shutdowns (and near shutdowns), the loss-of-bias anomaly, and status of hardware upgrades.

  ...  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 - a high radiation environment on April 11 likely would have triggered the ACIS TXINGs if any FI CCDs had been in operation at the time.

  ...  Presented poster on ACIS radiation monitoring at HEAD meeting.

  ...  Met with Chandra managers regarding future access to real-time ACE data.  Presented our current usage, and expectations for performance evolution and loss of observing efficiency in the absence of ACE data.

  ...  At the request of CDO, re-examining the TXINGs triggering algorithm.  Currently requires increasing rates, but are we missing valid radiation events by ignoring high but decreasing rates?  Any other improvements?

  ...  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

  ... Submitted summary of CCD working group activities for upcoming IACHEC newsletter.  Will be posted on astro-ph to better advertise IACHEC activities to the broader community.

  ...  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.  Plan for broken EGSE backup machine is to do nothing for now, but proceed with upgrades to Linux.

  ...  Work continues on upgrading TST machines to Solaris and then Linux.  Switch to Solaris complete.  Final testing of Linux is underway.


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