ACIS Instrument Support - Monthly Progress Report for June 2003

1. ACIS Characterization

1.1 Characterize and model radiation damage in ACIS CCDs

 [...  Began running new set of charge injection tests on I3.  Three
tests at three energies to explore the energy/voltage relation.
Initial results look similar to I0.

1.2 Monitor scientific on-orbit performance of ACIS

  ...  Continued analysis of ExtCalSrc data to study efficiency 
decrease at low energies.  Comparison of S1 and S3 data shows
essentially the same amount of absorption.  An independent ECS
analysis finds the same amount of absorption.  ECS data continue
to suggest a ~15% larger optical depth at ~0.7 keV than LETG
analyses.

  ...  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/).

1.4 Update and improve CCD simulation

  ...  Continued work on improving FI and BI CCD models with a more 
physical representation of the electron traps that cause CTI.


2. Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance.  No
anomalies.

2.2 Instrument science performance

 [...] Completed new ACIS memo on the dependence of ACIS performance
(CTI, gain, line width) on small temperature changes.  See ACIS
Memo #204.

  ...  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.

  ...  Continued to support charge injection operations by reviewing 
loads and comparing flight data to ground data to select new settings.


3. CXC Support

3.1 Provide user support

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

 [...] Participated in discussion with cal team on the absolute QE
of the ACIS CCDs.

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