ACIS Instrument Support - Monthly Progress Report for September 2019

1.  ACIS Characterization

1.1 Characterize and model radiation damage in ACIS CCDs.

  ...  Worked on new CTI correction coefficients for FI temperature dependent CTI correction.  Confirmed with SDS which CALDB files will need to be updated.

1.3 Monitor scientific on-orbit performance of ACIS

  ...  Following Chandra Normal Sun Mode safing action on September 5, verified ACIS was safe, monitored housekeeping data during recovery, and supported safe mode recovery.  Ran a CAP to collect an additional 80 ksec of ECS data during the shutdown spanning the full range of focal plane temperatures.

  ...  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 Twenty Years of Chandra Science Symposium on ACIS status and instrument monitoring.


2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance.  Reviewed trends in engineering data for the past 69 days; no unexpected trends were seen.

  ...  The EEPROM checksum was verified in the SEP0919B load.   Will continue to run monthly.  MIT telemetry processing will automatically check the results and send out an alert if the checksum is unexpected.

  ...  Participated in team review of quick-response anomaly web page for the DPA-A anomalous shutdown.

  ...  Participated in team review of ACIS Flight Software User's Guide.  Started more detailed discussion of instrument behavior when switching between BEPs.

2.2 Flight software maintenance

  ...  Flight software patch F-G-H (improved buscrash2) uploaded in June 2014.

  ...  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.

  ...  Continuing forward with ACIS patch level G-H-I.  This patch makes two changes to the current F-G-H patches -- updates buscrash2 patch to force end of science run following SCS107, and adds a new deahktrip patch to respond to "red alert" DPA component temperatures.  SOT and FOT SOPs written and released for review.  Confirmed default behavior of the deahktrp patch is what is intended.

2.3 Instrument science performance

  ...  Participated in monthly ACIS operations meeting.  Discussed ACIS flight software patch status, and questions from the team FSW User's Guide review.

  ...  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

  ...  Supported discussion of updates for the cycle 22 POG, whether recent ACIS cal updates need to be mentioned (no) and whether spatial windows are appropriately discussed (yes).

  ...  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 issues with the most recent tgain update, status on the gain droop correction, and contamination.

  ...  Answered SDS question on graded mode and CTI correction.

  ...  Submitted correction for CDO's X-ray Data Primer

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

  ...  Participated in planning telecon for next IACHEC meeting (April in Virginia).


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.  Performed monthly check of all ACIS hardware and software at the OCC.  Implemented further security improvements to the ACIS EGSEs.

4.2 Generation of commands for ACIS observations

  ...  Continued to assign SI modes for remaining observations in cycle 21.  Notified USINT contacts of issues and recommended changes to configurations.  Checking for existance of chip drop contingency modes.  Caught a bad optional chip order in an approved pool target list.

  ...  Fixed internal registry problem preventing SI mode assignment for some calibration observations.

  ...  Built and tested new SI mode for cycle 21 on the Engineering Unit.

  ...  Reviewed SEP0919A, SEP0619A, SEP0619B, and SEP0919B command loads.  Reviewed SEP2319 LTS OR list.

  ...  Assigned 5 SI modes.  Dropped chips from 4 ObsIDs

  ...  Checking on automated processes associated with SACGS.