ACIS Instrument Support - Monthly Progress Report for September 2020

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).


2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance.  Reviewed trends in engineering data for the past 60 days; no unexpected trends were seen.

  ...  The EEPROM checksum was verified in the SEP1220A load.   Will continue to run monthly.  MIT telemetry processing will automatically check the results and send out an alert if the checksum is unexpected.

  ...  The ACIS Engineering Unit was briefly down in mid-September due to a fault with the B-side power supply.  This was repaired and the EU is available for uplink command verification and patch validation.
  
2.2 Flight software maintenance

  ...  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 may have flattened out and started decreasing recently, potentially indicating the end of solar minimum.

  ...  Continued work on developing a QEMU ACIS processor emulator. On-going development involves:
  -- Continued bug fixes
  -- Modification of BEP emulator's telemetry architecture to fix issues when switching between BEPs A and B
  -- Emulation of the PSMC Side A and B DEA and DPA power control
  -- Replacement of hard-coded telemetry definitions with start-up loading of telemetry definition files (ttm)
  -- Started coarse emulation of active analog DEA/DPA voltage and current telemetry points

  ...  Continued team review of ACIS Flight Software User's Guide using the new version B released in April.  Finished section on changing the system configuration and began with housekeeping.

  ...  Updated documentation of ACIS data flow in response to ACIS team comments.

2.3 Instrument science performance

  ...  Supported response and recovery to the HRC side-A electronics anomaly.  Contributed to presentations "ACIS Operations Plan for Science Operations without the HRC anti-co Shield" and ACIS return to science review.  Supported HRC briefings and CAP reviews.  Revisited early studies on ACIS radiation damage from unprotected radiation belt transits and from solar storms.

  ...  Participated in monthly ACIS operations meetings.  Discussed the ongoing HRC anomaly, radiation mitigation strategies, and EU status.

  ...  Continued daily quick-look processing of ACIS telemetry and maintained Web interface to ACIS real-time data.  Corrected problem with times associated with May safe mode.

  ...  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 status of tgain, scheduling of ECS measurements during the science orbit, and contamination calibration.

  ...  Continued to maintain ACIS calibration database of ground and flight data products.

  ... Participated in planning telecon for the IACHEC meeting.  Full meeting originally planned for April 2020, postponed to September 2020, and further postponed to April 2021.  Exploring adding an additional virtual meeting in November 2020, directed at a more general interest audience.


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.  Remotely checked on status and restarted frozen window server.

4.2 Generation of commands for ACIS observations

  ...  Completed draft of a memo describing the 2019 observation of Sco X-1 with incorrect spatial window commanding and the ACIS team response.

  ...  Completed the initial SI mode assignment for cycle 22.  Contacted CXC USINT for the few cases with configurations that require further consideration efore assignment.

  ...  Commented on the USINT letter to observers for cycle 22.

  ...  Worked with USINT to fix problems with frame-time in an observation.

  ...  Worked with USINT on finding an appropriate subarray for an observation.

  ...  Answered USINT question on aimpoints and their position on the CCD.

  ...  Reviewed SEP2120A and SEP2120T command loads.  Reviewed SEP2820 and OCT0520 LTS OR lists, SEP2120 preliminary schedule, and SEP2120 final OR list.

  ...  Assigned 9 SI modes.  Dropped chips from 3 ObsIDs.

  ...  Checking on automated processes associated with SACGS.