ACIS Instrument Support - Monthly Progress Report for April 2010

1.  ACIS Characterization

1.1 Characterize and model radiation damage in ACIS CCDs

  ...  Continued work on irradiation/annealing tests done at GSFC
in 2005.  Writing up as a paper.

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)

  ...  Beginning to recalibrate CTI-sacrificial charge correction
used in monitoring.  Quiescent background rates are now trending
downwards as the new solar cycle starts, making recalibration
possible (and necessary).

  ...  Collected new raw frames and updated monitoring web page.
(http://space.mit.edu/~fergason/acis/raw.html)  Examined raw images
for hot pixels and low pixel values.


2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance. 
The ACIS engineering division has reviewed the last two months of
engineering data and found no unanticipated trends. 

2.2 Flight software maintenance

  ...  Successfully loaded a new ACIS flight software patch (standard
patch release E, version 48).  

  ...  During the initial upload of the new patch, one command block 
was not received by the spacecraft.  This left the ACIS command FIFO 
partially full, preventing further commands from being accepted. Our
remedy was to execute an ACIS warm boot.  All patches were then deleted, 
after which they were reloaded without incident and ACIS was rebooted.
This prompted much discussion of what the response should be to a stuck
FIFO.

2.3 Instrument science performance

  ...  Continued investigation into whether ACIS can act as it's own
radiation monitor, prompted by action from the thermal working group
which is concerned about the continued degradation of EPHIN.  Correlating
ACIS exposure record data with GOES and EPHIN.

  ...  Participated in monthly ACIS operations meeting.  Discussed
engineering unit status, new flight software patch, PSMC thermal
model, and a plan for validating SIMODEs in the absence of the ACIS
engineering unit.

  ...  Participated in radiation working group telecon.

  ...  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

  ...  Updated ACIS memo listing calibration ObsIDs and 
observation characteristics (ACIS Memo #165).

3.2 Provide data analysis support

  ...  Participated in IACHEC meeting (International Astronomical
Consortium for High Energy Calibration).  Organized new working group
on CCD issues, including CTI.

  ...  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.


Outreach:

none this month

all recent memos available at http://space.mit.edu/ACIS/iacis.html