ACIS Instrument Support - Monthly Progress Report for November 2005

1.  ACIS Characterization

1.1 Characterize and model radiation damage in ACIS CCDs

  ...  Poster presentation at Six Years of Science with Chandra meeting
on the May 2005 radiation damage/annealing experiments.

  ...  Worked with PSU to update the time-dependent CTI information
in their CTI corrector.

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.  (http://space.mit.edu/~cgrant/monitor.html)

  ...  Continued work on memo for the operations team on the consequences
of a future, unprotected radiation belt transit by ACIS.  Motivated
by recent Chandra safe mode simulation. 

  ...  Examined some of the raw frames collected on-orbit.  Created
event finding, image slicing, and display tools to analyze raw frames.

  ...  Analyzed raw frames to better understand the nature of the 
excess background events on the node boundaries.  Presented results
to ACIS calibration group.

  ...  Attended Chandra calibration workshop.

1.4 Update and improve CCD simulation


2.  Engineering

2.1 Instrument hardware engineering performance

  ...  We have investigated the details of the A/D converter anomaly 
which was noted after the last (unscheduled) DEA power cycle (day 258).  
Using the engineering test bed we verified that the calibration signal 
for the A/D is generated as a part of the Warm Boot process (and by no 
other event).  We further verified that the A/D calibration signal is 
provided to the video boards (the identical chip is used in all ACIS 
applications) at the start of each science run.  An internal report has 
been written by Dorothy Gordon.  

  ...  There was a brief flurry of concern that the DEA/DPA electronics 
had experienced a sudden increase in operating temperature, but further 
review shows that the increase is both modest and expected, given the 
gradual increase of temperature in the ISIM thermal environment.

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

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 "monthly" ACIS operations meeting.  Discussed
DEA anomaly and new memo from Dorothy Gordon, thermal trends in the
instrument, etc.


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 modelling discussion group.
Presented analysis of raw frames to better understand the nature
of the excess background events in node boundary columns.

  ...  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:

Poster at Six Years of Chandra Science meeting, 2-4 Nov 2005
     * LaMarr et al., "Recent ACIS CCD Irradiation Experiments"

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