ACIS Instrument Support - Monthly Progress Report for September 2003

1. ACIS Characterization

1.1 Characterize and model radiation damage in ACIS CCDs

  ...  Completed running charge injection tests on I3.  Two tests 
at additional energies.  Data analysis will continue.

 [...  Began taking a series of data in full-frame raw mode for
performance verification and monitoring.  First set includes
S2 and S3.  Future sets will sample all the CCDs.  These are 
the first such data since September 1999.

1.2 Monitor scientific on-orbit performance of ACIS

  ...  Continued analysis of ExtCalSrc data to study efficiency 
decrease at low energies.  Verifying spatial non-uniformity
of contaminant distribution.

  ...  Continued monitoring of ACIS CTI.  No significant changes beyond 
the long term slow increase.  (http://space.mit.edu/~cgrant/cti/)

  ...  Continued monitoring of ACIS gain.  All CCDs stable with a slow 
decline in gain slope (ADU/eV) except for I2 which continues to vary.
(http://space.mit.edu/~cgrant/gain/).

 [...] Presented poster at "Four years of Chandra Observations" Symposium
on ACIS performance monitoring.

1.4 Update and improve CCD simulation

  ...  Continued work on improving FI and BI CCD models.  Added option 
that allows for specifying precise intrapixel location of incoming photon.

  ...  Worked on the CTI simulation code for the new version of the 
CCD model. Implemented  shifting of charge packet center from a 
center of a single gate to a center of two gates during clock 
overlapping period.  Implemented spilling of charge packet under 
2 gates during clock overlapping period.

  ...  Analyzed another set of data with variable input signal
in order to measure volume-vs-charge relationship  for very small 
charge packets.


2. Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance.
No new anomalies or trends.

 [...  Providing engineering support for planning a possible instrument 
bakeout.

2.2 Instrument science performance

  ...  Participated in ACIS operations bakeout planning meeting.

 [...] Updated ground software for the change in the format of
ACIS uplink tables to accomodate the expected bias map creation
times that Royce will be computing for each ObsID.

 [...] Annotated and verified the uplink commands for ACIS bakeout.

  ...  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.

 [...] Participated in ACIS telecon.


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 RMF 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.


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