ACIS Instrument Support - Monthly Progress Report for December 2021

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 the March HEAD meeting, examining the correlation between the quiescent particle background measured on ACIS and that by the AMS particle experiement on the ISS.

 
2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance.  Engineering trending over the past 60 days is nominal.

  ...  The EEPROM checksum was verified in the DEC0621B load.   Will continue to run monthly.  MIT telemetry processing will automatically check the results and send out an alert if the checksum is unexpected.

  ...  Continued weekly physical audit of the ACIS Engineering Unit lab. 

  ...  Responded to FOT request to change yellow/red low limits for 1DP28[A|B]VO and 1DE28[A|B]VO, the +28V input voltage for the DPA and DEA, as these limits will be increasingly violated heading toward low perigee.  Limit violations are understood and limits were changed in January.

2.2 Flight software maintenance

  ...  New ACIS flight software patch, fepbiasrec has been written and tested, but is currently on hold in favor of work on the improved txings patch. This patch forces the FEP to recompute its bias map after being power-cycled, to prevent the anomaly that occurred over the summer with consecutive event histogram runs.

  ...  Exploring improvements to the ACIS radiation monitor, txings, with the goal of improving the sensitivity of radiation triggering. Investigating existing ACIS txings data and ACIS bias maps and identifying times of high background. Added HRC anti-co rates to the txings plots to help fill in the gaps and confirm real radiation events.  Restarting testing of the full txings parameter space on the MKI computing cluster.  

  ...  ACIS flight software patch G-H-I (improved buscrash and new deahktrip) uploaded on January 24, 2020.  First new patch set since June 2014.  No issues to date.

  ...  We continue to monitor threshold crossing rates.  The current TXINGS parameters were last updated on July 28, 2016.  Threshold crossing rates have been decreasing, indicating the transition from solar minimum to solar maximum. We plan to lower the trigger threshold early in 2022.

  ...  Continued team review of ACIS Flight Software User's Guide, with sections on example scenarios of timed exposure and continuous clocking science runs.  Worked on improving the examples with more standard SI modes.  New version released 12/24.

2.3 Instrument science performance

  ...  Participated in monthly ACIS operations meeting. Discussed the new roll limits due to the expanded use of the SPM and the implications for ACIS, and plans for a future focal plane heating time constant test.

  ...  Participated in SOT radiation working group telecon.

  ...  Continued daily quick-look processing of ACIS telemetry and maintained Web interface to ACIS real-time data.

  ...  Corrected telemetry corruption in ObsID 24810, per GOT request.

  ...  Continued to publish the "annotated DOT" timeline reports.


3.  CXC Support

3.1 Provide user support

  ...  ACIS memo listing calibration ObsIDs and observation characteristics (ACIS Memo #165) will no longer be updated.  Functionality is replaced by new web page (http://acis.mit.edu/asc/evt-page.html), which provides the same information but is more automated.

3.2 Provide data analysis support

  ...  Participated in CXC Cal/Ops ACIS response discussion group. Discussed plans for a focal plane cooling/heating test, calibration below -120C, and contamination measurements.

  ...  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 Wayside OCC.  Restarted both EGSE machines routinely.

4.2 Generation of commands for ACIS observations

  ...  Continued work on assigning SI modes to cycle 23 observations and clearing problematic configurations.

  ...  Provided input to SOT MP on the ACIS use of OR lists and tables.

  ...  Continued beta testing and documentation review of new python based command generation wrapper scripts.

  ...  Provided emergency software update to SACGS after unexpected, unadvertised changes to the OCAT extraction tools in CXCDS10.10.2.

  ...  Reviewed SAR for focal plane temperature cooling/heating test.

...  Reviewed DEC1321A command load, DEC1321 final OR list, DEC1321 and DEC2021 preliminary schedules, and DEC2721 and JAN1722 LTS OR list.

  ...  Assigned 2 SI modes. Dropped chips from 5 ObsIDs

  ...  Built a new SI mode for the cooling/heating test.

  ...  Checking on automated processes associated with SACGS.