ACIS Instrument Support - Monthly Progress Report for April 2016

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).

  ... Requested new raw mode frames.  Second set collected in April.  Both March and April sets analyzed and posted to http://space.mit.edu/home/fergason/acis/raw.html.

  ... Prepared slides for and presented at the Chandra Quarterly in April.

  ...  Updated yellow low limits for BEP_OSC and BEP_PCB temperatures in DEA housekeeping.  Updated contact information for alerts from DEA housekeeping.

2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance.  Engineering housekeeping remains nominal with one exception.

  ...  Lost reliable temperature readings for the case lid temperature of the PSMC (1PIN1AT).  The symptom is random fluctuations between believable values (for periods of hours) followed by non-physically large values (for periods of 10s of minutes).  These symptoms could be caused by intermittent open circuits in the two wired-in-series 2Kohm RTSd, intermittent open circuits in the wiring leading to the PSMC which contains the measurements circuitry, or intermittent failure of a housekeeping MUX within the PSMC.  1PIN1AT served a diagnostic function to validate the thermal model which represented the radiative heat flow from the PSMC to the interior of the SIM.  The interior temperatures of the PSMC (1PDEAAT and 1PDEABT), which monitoring the operating health of the PSMC, remain stable.

  ...  Removed 1PIN1AT from automated alert system.

  ...  Reviewed ATS commands which will run EEPROM checksum commands in the daily load.  Approved by the FDB April 7.  Commands were run in the MAY0216 load and are planned to be rerun on a monthly schedule.

  ...  Tested new ACISpy tools for plotting ACIS engineering and DEA housekeeping values.

  ...  Reviewed updated versions of "atomic" ACIS SOT SOP (deaa_on, deaa_off, etc.)

  ...  Created new SOT SOP, switch_bepb_a, and updated switch_bepa_b.  Both are under review.

2.2 Flight software maintenance

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

  ...  Documenting procedures for creating and testing ACIS flight software patches.

2.3 Instrument science performance

  ...  Participated in monthly ACIS operations meetings.  Discussed 1PIN1AT, new BEP temperature yellow low limits, and bakeout studies.

  ...  Received presentation slides and written report by MIT materials science graduate student examining the ACIS reverse annealing experience and confirming our qualitative explanation with a quantitative analysis.  Working on reproducing quantitative results to explore limits on temperature and length of bakeout scenarios.

  ...  Attended Chandra Safe Mode Overview briefing.

  ...  Attended briefing on ECS scheduling guidelines with FOT MP.

  ...  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 new web page (http://acis.mit.edu/asc/evt-page.html), which provides the same information but is more automated.

  ...  Reviewed ACIS update for Chandra newsletter.

3.2 Provide data analysis support

  ...  Participated in CXC Cal/Ops ACIS response discussion group.  Discussion included contamination measurements and modeling, DH heater off decision, and updating ACIS RMFs.
  
  ...  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 OCC.  Performed monthly check of all ACIS hardware and software.  

  ...  Wrote a memo for ACIS operations team on the software and hardware in use in the ACIS OCC area.

...  Updated a memo for ACIS operations team on how to access DEA and engineering housekeeping data from Chandra telemetry dumps using MIT tools.

4.2 Generation of commands for ACIS observations

  ...  Continued review and updating of SACGS documentation (SACGS = SOT ACIS Command Generation System).  Updated documentation for assigning/building SI modes.

  ...  Continuing familiarization with SACGS operation and under-the-hood functioning.  Fixed error (again) in SACGS script that caused ACIS Tables to not get copied to monitoring web pages.

  ...  Reviewed APR1816 preliminary schedule and final OR list.

  ...  Assigned one SI mode on request.  Dropped chips from two obsids.  Installed new ACIS tables at the OCC.

  ... Reviewed new preliminary schedule webpage format from SOT MP.

  ...  Checking on automated processes associated with SACGS.