ACIS Instrument Support - Monthly Progress Report for November 2023

1.  ACIS Characterization

1.3 Monitor scientific on-orbit performance of ACIS

  ...  Due to high radiation environment, the ACIS team recommended a shutdown of science observing on November 5.  Science was resumed two days later.  Reviewed memo on radiation shutdown decision process.

  ...  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).

  ...  Study on ACIS particle background variability, comparing ACIS reject rates to similar reject counters on XMM EPIC-pn and the AMS particle experiment, has been submitted to ApJ.

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

  ...  Submitted abstracts to SPIE and HEAD meetings on "The Advanced CCD Imaging Spectrometer on the Chandra X-ray Observatory: Twenty five years of on-orbit operation".


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 NOV0723A loads. 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.  On Nov 6 the EU was noted to be in an anomalous condition on side-A. As in past occurrences, a shutdown, plus physically working the side-A limit potentiometer was sufficient to clear the anomaly.  After power up, the EU was nominal.

2.2 Flight software maintenance

  ...  ACIS flight software patch H-J-K uploaded on September 19, 2022.  First new patch set since August 2022.  No issues to date.

  ...  We continue to monitor threshold crossing rates which continue to drop. The current set of TXing parameters were uploaded on October 11, 2023.

2.3 Instrument science performance

  ...  Continued daily quick-look processing of ACIS telemetry and maintained web interface to ACIS real-time data.  Planned for ACIS monitoring during Nov 4 power outage at 60 Garden Street.  Improved daily plots of TXings and HRC/Antico rates.

  ...  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://acisweb.mit.edu/asc/evt-page.html), which provides the same information but is more automated.

3.2 Provide data analysis support

  ...  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

  ...  Continuing to work with USINT on remaining problematic ACIS configurations in cycle 25.  Checked for the existance of SI modes for all chip drop configurations.  Number of ObsIDs with unassigned SI modes dropped from 28 to 5.

  ...  Reviewed CLD files for new 3-CCD ECS configuration.

  ...  Presented implementation plan for new Next-In-Line SI mode to Mission Planning Constraints Working Group.  Will be implemented after guideline and load review scripts are updated.  Reviewed proposed changes to ACIS script.

  ...  Ran test OR list through SACGS OR list review script with no problems.

  ...  Reviewed NOV2723A command load; NOV2723 preliminary schedule; and DEC1123(x2) LTS OR list.  Assigned 23 SI modes.

  ...  Checking on automated processes associated with SACGS.