ACIS Instrument Support - Monthly Progress Report for June 2024

1.  ACIS Characterization

1.3 Monitor scientific on-orbit performance of ACIS

  ...  Due to a high radiation environment, the ACIS TXings radiation monitor trigerred a shutdown of science observing on June 7.  Shutdown was nominal.  During the shutdown, ran CAP 1746 to collect 24-hours of ECS data.

  ...  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).

  ...  Gave a talk and submitted a proceedings paper at the SPIE Astronomical Telescopes + Instrumentation 2024 meeting on "The Advanced CCD Imaging Spectrometer on the Chandra X-ray Observatory: Twenty five years of on-orbit operation".

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

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 JUN1124A 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.  Swapped the image loader back to the original unit which stopped the unexpected FEP firmware ltchups.  Resolved issues with remote secondary temperature sensor in the ACIS Engineering room

2.2 Flight software maintenance

  ...  ACIS flight software patch H-J-K uploaded on September 19, 2023.  First new patch set since August 2022.  No issues to date.

  ...  Continued development of diagnostic BEP/FEP memory dump procedures.  After resolution of unexpected FEP latchups on the EU, resumed work on dumping BEP and FEP memory without FEP latch-ups.

  ...  We continue to monitor threshold crossing rates which have recently flattened out. The current set of TXing parameters were uploaded on May 7, 2024.

2.3 Instrument science performance

  ...  Continued daily quick-look processing of ACIS telemetry and maintained web interface to ACIS real-time data.  Worked with CXC SysHelp to adapt MIT processing procedure to the new 2-factor authentication system for SAO access.

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


3.  CXC Support

3.1 Provide user support

  ...  Technical reviewer for Chandra cycle 25 high count rate proposals

  ...  ACIS memo listing calibration ObsIDs and observation characteristics (ACIS Memo #165) will no longer be updated.  Functionality is replaced by 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.

  ...  Responded to to query from the DS pipeline about bias feature in ObsID 29429.  Anomalously low pixels happen with the A/D converters are saturated with charge, mostly likely due to cosmic rays.  Under some circumstances they can propagate into the bias maps, as in this case.

  ...  Worked as editor for IACHEC 2023 meeting summary. Submitted to arXiv in July.  2024 meeting summary in work.

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 to work with USINT on remaining problematic ACIS configurations in cycle 25.  Down to a single ObsID, an observation of the Crab which requires more consideration.

  ...  Reviewed JUL0124A command load; JUL0124 final OR list; JUL0124 and JUL0824 preliminary schedules; and JUL1524 LTS OR list.
 
  ...  Checking on automated processes associated with SACGS.