ACIS Instrument Support - Monthly Progress Report for May 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).

  ...  Submitted abstract to June HEAD meeting on "The Effects of Orbital Environment on X-ray CCD Performance".  Presents what we've learned from long-term CCD performance on Chandra and Suzaku and extrapolates to future missions in LEO and L2.


2.  Engineering

2.1 Instrument hardware engineering performance

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

  ...  SOP for flight procedure "switch_deaa_b" that switches PSMC power from DEA-A to DEA-B is being revised to include more diagnostic information after thinking through actual scenarios that would require this procedure.

  ...  SOP for responding to video board and FEP anomalies out for review.  Some corrections made.

  ...  Commands to dump the EEPROM checksum created and in ACIS tables.  SOP to be written.

2.2 Flight software maintenance

  ...  Flight software patch F-G-H (improved buscrash2) uploaded in June 2014 and has continued to run with no issues.

  ...  Considering improvements to txings, or to ACIS radiation monitoring more generally, in response to potential loss of ACE real-time data.  Re-examining ACIS threshold crossings data immediately before Chandra radiation shutdowns to find any good cases that are currently missed by the TXINGs algorithm.  Preparing results for team.  Required further book-keeping between radiation shutdown listings kept at MIT and CXC.

  ...  Ask to predict whether bright source TOO would trigger a TXINGs radiation shutdown.  Predicted no, and was correct.

2.3 Instrument science performance

  ...  Participated in monthly ACIS operations meeting.  Discussed progress in DEA/FEP diagnostic procedures and flight EEPROM testing, presentation for turning on the DH heater long-term, and plans for bakeout studies.

  ...  Reviewed proposed slides for community-wide briefing on the possible future DH heater turn-on.

  ...  Reviewed CXC SOT memo on radiation shutdowns in December 2014.

  ...  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, the ACIS detector housing heater, contamination, and potential future bakeout studies.

  ...  Participated in discussions regarding future studies on potential ACIS bakeout.  Reviewing previous work including memos, published papers, and presentations from the last time bakeout was considered (2004).  

  ...  Continued to maintain ACIS calibration database of ground and flight data products.
  
  ...  Reviewed slides for annual Chandra thermal and constraints briefing.


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.  

4.2 Generation of commands for ACIS observations

  ...  Started training in ACIS command generation and operations procedures.  Acquiring new accounts and passwords and attending weekly operations briefings.  Eventually will take over some of Royce Buehler's tasks when he retires at the end of the year.