ACIS Instrument Support - Monthly Progress Report for January 2005

1.  ACIS Characterization

1.1 Characterize and model radiation damage in ACIS CCDs

  ...  Continued study of our CTI/background relation using the
alternating exposure mode observations and the Oct 2003 solar
activity.  Preparing a summary memo with new correction factor.

  ...  Planning for next set of cold irradiation and bakeout lab
tests.  Possible opportunity in late-April.  Discussing test
parameters and reviewing data for candidate CCDs.  

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

1.3 Monitor scientific on-orbit performance of ACIS

  ...  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)

1.5 Analyze data from engineering unit ACIS CCDs

  ...  Continued comparison of non-flight ACIS BI CCD to non-flight XIS-2 
BI CCD to help understand flight cross-calibration data as they become
available after launch.  May also help in better analyzing data from
flight BI CCDs.


2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance.  A review 
of engineering parameters for the past 60 days show no unusual behavior save 
the expected heating due to ISIM warming during the current orbital phase.

  ...  The ACIS Engineering Group participated in the Chandra Thermal Working 
Group meeting at which we changed two of the Power Supply and Mechanism 
Controller (PSMC) thermal monitor limits to agree with pre-flight box 
level qualification limits.

2.2 Flight software maintenance

  ...  Investigated ACIS runs that terminated with an error.  Eleven
6-CCD TeRaw mode runs (out of 22) ended abnormally when the following
startScience caused FEP resets.  A few 1-CCD TeRaw mode and event
histogram also ended this way.  Future raw mode runs which are immediately
followed by a science observation will have a larger delay to allow
time to clear the ACIS buffers.

2.3 Instrument science performance

  ...  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 operations meeting.  Reported on CTI status
after January solar activity (no discernable change).  Discussed status
of ACIS EGSE move, plans for new CCD irradiation tests and reviewed thermal
status.

2.4 Participate in Chandra activities

  ...  Supported CAP #953 review.  CAP executes a standard I-array CTI
measurement using an RTS.


3.  CXC Support

3.1 Provide user support

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

  ...  Supported investigation of ObsID 6148 problem.  Observation
was executed as commanded, however observer did not correctly
specify the desired spatial windows.  Suggested documentation
changes to improve the description of window specification.

3.2 Provide data analysis support

  ...  Working with CXC Cal on CTI correction calibration.  Tested
map for I3 at -110C.  Provides similar correction as the PSU CTI
corrector.

  ...  Provided plots for CUC calibration presentation.

  ...  Continued to maintain ACIS calibration database of ground and 
flight data products.

  ...  Protected ACIS subassembly data tapes which were shuffled in the
buliding construction related moves.

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.  

  ...  Continued planning for move of the ACIS EGSE setup to a new location 
at the OCC.  Supported ACIS Operations team meeting to discuss plans and
status.  All software in old and clone machines is identical (excluding 
unavoidable hardware architecture differences).  Validation tests nearing
completion.

Outreach:

None


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