ACIS Instrument Support - Monthly Progress Report for April 2024

0.  Supported preparations for the Operation Paradigm Change Review

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).

  ...  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 accepted by ApJ.  (arXiv:2405.06602)


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 APR0824A 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.  All nominal in April.

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.  Testing of FEP memory dump commands in realistic conditions on the EU has revealed differences from the flight.  Investigating EU hardware.  Draft memo "Preventing FEP Firmware Latch-Ups" is under review.

  ...  Participated in a review of the 2005 ACIS DEA anomaly and what the ACIS ops response would be to a recurrence. Provided comments on updated documentation.

  ...  We continue to monitor threshold crossing rates which have recently flattened out. The current set of TXing parameters were uploaded on October 11, 2023.  A SAR has been submitted to further update TXing parameters in MAY0624.  Reviewed the SAR and the CLD.

2.3 Instrument science performance

  ...  Participated in monthly ACIS operations meeting.  Discussed instrument status (good), focal plane temperatures during perigee (high but OK), the new thermal model for 1DPAMYT, new temperature limits for the ACIS focal plane, and preparation for BEP anomalies.

  ...  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

  ...  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.

  ...  Technical reviewer for HST joint observations.

3.2 Provide data analysis support

  ...  Participated in CXC Cal/Ops response discussion group.  Discussed gain uncertainties and new focal plane temperature limits; calibrating RMFs at warm FP temperatures; and an update from HETG.

  ...  Responded to query from the DS pipeline about ObsID 43523.  Repaired a single bit error in a bias packet and sent the replacement SSR dump file back to CXC.

  ...  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

  ...  Participated in working group on changes to OR list format.

  ...  Reviewed APR2024 command load; APR2024 final OR list; APR2024 preliminary schedule; and APR2224 and MAY0624 LTS OR lists.  Reviewed APR1524 test preliminary schedule.

  ...  Checking on automated processes associated with SACGS.