ACIS Instrument Support - Monthly Progress Report for March 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)

  ...  Preparing 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).

  ...  Presentation on ACIS status at Chandra Quarterly Review.

  ...  Requested new raw data frames for periodic monitoring.


2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance. 
ACIS hardware on-orbit continues to function nominally.

  ...  In response to ACIS Engineering Unit anomaly last month,
all flight spare boards are being tested.

2.2 Flight software maintenance

  ...  Presented new flight software standard patch release E to FDB.
Approved.  Was successfully uploaded April 7.

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.  Compiled 
full mission exposure record data for testing possible triggers.

  ...  Participated in monthly ACIS operations meeting.  Discussed
engineering unit status and new flight software patch.

  ...  Participated in radiation working group telecon.  ACIS team
approved changing radiation belt backoff time from 5 hrs to 4 hrs
from perigee.

  ...  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

  ...  Answered further user questions on data analysis problems 
with measuring Fe-55 decay in the ACIS calibration source.

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

3.2 Provide data analysis support

  ...  Preparing for upcoming IACHEC meeting (International Astronomical
Consortium for High Energy Calibration).  Organizing new working group
on CTI.

  ...  Participated in CXC Cal/Ops modeling discussion group.  Discussed
status of temperature-dependent CTI correction software and CC-mode 
calibration.

  ...  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.  Replaced misbehaving DAT drive.


Outreach:

none this month

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