ACIS Instrument Support - Monthly Progress Report for March 2008

1.  ACIS Characterization

1.1 Characterize and model radiation damage in ACIS CCDs

  ...  Continued work on a paper presenting the results of the 
radiation damage/reverse annealing tests done at GSFC in 2005.

  ...  Executed new SI modes which allow more grades to be 
telmetered.  These SI modes are being used to compare TE and CC 
mode grade rejection to help calibrate CC mode.  Four ObsIDs
(57928, 57915, 57899, 57891) in March.

  ...  Attempted to calibrate continuous clocking mode CTI.
Currently, available data do not have sufficient counts for 
accurate measurement.  Investigated 1-D uniformity of continuous
clocking versus timed event mode data.

1.3 Monitor scientific on-orbit performance of ACIS

  ...  Continued monitoring of ACIS CTI, gain, trailing pixel 
pulseheight, detector efficiency, corner pixel distribution, 
and spectral line centroid and width.  Updated monitoring web 
pages.  (http://space.mit.edu/~cgrant/monitor.html)

1.7 Produce novel data products from the MIT ACIS database

  ...  Provided pre-launch eventlists to instrument PI from the 
instrument team archive of data taken at Ball Aerospace.


2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance.
A review of the past 60 days' engineering data reveals no
unanticipated trends.  The instrument continues to operate nominally.

  ...  Turning off the Detector Housing heaters for short intervals
has validated our thermal models and confirmed that the primary
housing survival heater is functioning as predicted.  Flight Directors
Board has approved turning off the DH heater permanently.  This will
take place in early April.

  ...  Reviewed generic CAPs to turn on and off the Detector Housing 
heater.

2.3 Instrument science performance

  ...  An ACIS anomaly occured during ObsID 7783 on March 11 when two
FEPs reset and stopped reporting data.  The anomaly cleared when the
power was cycled before the next observation.  This is similar to
an anomaly 11 months ago during ObsID 7647.

  ...  Participated in monthly ACIS operations meetings.  Discussed
detector housing temperatures, the ObsID 7783 anomaly and software
patch status.

  ...  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).

  ...  Answered questions about the spatial and spectral properties
of ACIS contamination and provided data analysis help.

3.2 Provide data analysis support

  ...  Provided final reviews of ACIS instrument sections for the
Chandra Senior Review. 

  ...  Participated in CXC Cal/Ops modeling discussion group.

  ...  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.

  ...  Continued work on improving configuration management of 
the ACIS workstations in the TST area of the Chandra OCC.  Work 
nearly complete.


Outreach:

Mentor to high school students participating in the Chandra 
Astrophysics Institute (C. Grant)


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