ACIS Instrument Support - Monthly Progress Report for June 2005

1.  ACIS Characterization

1.1 Characterize and model radiation damage in ACIS CCDs

  ...  Cold irradiation and bakeout test at GSFC, May 2005

      * Final trip to GSFC to copy remaining data to tape and
bring back to MIT.

      * Systematic analysis of all data including fitting CTI and
trailing pixels, identifying problem data sets and analyzing CTI
versus temperature trends.

      * Reassembled experimental setup at MIT for additional testing.

      * Presented initial results of cold irradiation and bakeout
test to ACIS telecon group on 15 June.  Found a relatively small CTI
degradation from annealing, similar to flight experience but
different from 2002 ground test.  Differences are not due to
proton energy variations nor CCD-to-CCD variations.  Further
analysis ongoing to better understand systematic errors and
temperature variations.

  ...  Continued taking a series of data in full-frame raw mode for
performance verification and monitoring.  Four ObsIDs this month with
data in both the ACIS-I and ACIS-S configurations.

1.3 Monitor scientific on-orbit performance of ACIS

  ...  Writing SPIE Proceedings paper on long-term trends in ACIS
radiation damage.  Will be presented at SPIE meeting in August.

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

  ...  Fixed intermittent bug in spectral line and contamination 
monitoring code.

1.4 Update and improve CCD simulation

  ...  Continued effort to improve fidelity of the BI CCD simulator
at low energies.


2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance. The
ACIS instrument continues to perform nominally.

2.2 Flight software maintenance

  ...  Continued study of the ObsID 5645 anomaly (SPR 138, M05040701).
Finished an interim report (ftp://acis.mit.edu/pub/SPR138-0.4.pdf).
This document and its conclusions will be discuss at the next ACIS
operations team meeting.

2.3 Instrument science performance

  ...  Participated in ACIS telecon on possible ACIS bakeout.  Presented
initial results from GSFC irradiation experiment.

  ...  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 monthly ACIS operations meeting.  Discussed 
progress in configuration control of ACIS monitoring machines, focal
plane cooling test and the GSFC irradiation experiment.


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

  ...  Working with CXC Cal on CTI correction calibration.  Tested a
set of maps created with more recent data (May 2004 - May 2005).
Adding these into a future CALDB will better match the time
dependence of the response.

  ...  Participated in CXC Cal/Ops modelling discussion group.  Discussed
including time dependence in CTI 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.

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


Outreach:

None


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