ACIS Instrument Support - Monthly Progress Report for January 2007

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, and 
spectral line centroid and width.  Updated monitoring web pages.
Did a more comprehensive check for anomalous data points -- all
were due to bad fits or extremely high background conditions.  
(http://space.mit.edu/~cgrant/monitor.html)

  ...  Continued a more comprehensive study of the effect of 
focal plane temperature variations on the metrics used in ACIS
monitoring.  When complete, will be used to define temperature
filter criteria more appropriate to the data.

  ...  Finished work on memo for the operations team on the 
consequences of a future, unprotected radiation belt transit by 
ACIS.  Distributed widely and posted on ACIS web pages in early 
February.  (http://space.mit.edu/~cgrant/acis.html and 
http://space.mit.edu/ACIS/iacis.html)

  ...  Presented ACIS SI team report at the Chandra Quarterly 
Review.

  ...  Compared contamination deposition rates from the L-complex
and the Al-K line.  The general shape of the optical depth versus
time curves are similar at both energies and for different regions
of the CCD, but do not match the shape of the C-K edge measured by
the LETG.  Working on improving the statistics in this analysis.

2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance.
ACIS engineering parameters remain nominal.

  ...  The ACIS hardware has now accumulate a month's running 
time in it's lower-power mode wherein we turn off both unused 
FEPs and DEA channels when not required for the science mode in 
use.  This seriously lowers the operating temperature of the PSMC 
and will greatly help avoid yellow temperature limit violations 
for this assembly.

  ...  Lowered (again) some yellow low temperature limits in 
response to the new FEP power-down paradigm.

2.2 Flight software maintenance

2.3 Instrument science performance

  ...  Participated in monthly ACIS operations meeting.  
Discussed dropping E1300 as a radiation trigger, lowering DPA 
housekeeping yellow limits and the HST/ACS failure.

  ...  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.

2.5 Participate in Chandra activities


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 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:

None

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