ACIS Instrument Support - Monthly Progress Report for September 2004

1. ACIS Characterization

1.1 Characterize and model radiation damage in ACIS CCDs

  ...  Continuing test of our CTI/background relation by running a series 
of alternating exposure mode observations with a grid of exposure times.  
In September there were three runs with frametimes of 2.0s, 3.5s and 4.0s,
alternating with a standard frametime of 3.2s.  This second set of data
will be completed in October.

1.2 Monitor scientific on-orbit performance of ACIS

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

1.3 Update and improve CCD simulation

  ...  Paper on ACIS bakeout tests accepted to IEEE Trans. on Nucl. 
Devices, "Anomalous Annealing of a High-resistivity CCD Irradiated at Low 
Temperature".


2. Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance. The ACIS 
instrument continues to function nominally.  A review of the past 60 days 
engineering data revels no unexpected trends.

  ...  Began planning an ACIS thermal test to compare the current cooling
profile with previous ones.  Large changes in the profiles could indicate
additional contamination on the CCDs themselves.  Originally scheduled for
October, now rescheduled for December.

2.2 Flight software maintenance

  ...  Opened a new Software Problem Report (SPR 137): "No way of 
terminating an ignoreInitialFrames wait during FEP bias creation".  The 
proposed ACIS thermal test would be performed in telemetry format 1 with 
the CCDs clocking.  A few options have been considered to reduce the 
science telemetry to allow as much room as possible for housekeeping 
information, one of which is to take a bias with a large value for 
ignoreInitialFrames.  There is, however, no existing ACIS command that can 
break out of this delay prematurely.

  ...  Developed and reviewed Engineering Change Order (ECO 36-1031) to 
respond to SPR 137.  A set or writeFep commands have been developed and 
tested that will cause the FEPs to break out of their ignoreInitialFrames 
loop.  (http://acis.mit.edu/pub/fepignorebreak-01.pdf)

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 telecons on the possible ACIS bakeout.  


3. CXC Support

3.1 Provide user support

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

  ...  Reviewed ACIS chapter of the Proposers Observatory Guide.  Sent
comments to CXC.

  ...  Answered CXC helpdesk question regarding mkinstmap and maskfiles.

3.2 Provide data analysis support

  ...  Working with CXC Cal on CTI correction calibration.  Current
calibration products were provided by MIT, but future updates will
need to be created by CXC.  Tested new maps for S0, S4 and S5 which
have no CTI correction option at the present.  Results are very positive
and are posted on the web:  http://space.mit.edu/~cgrant/cticorr/

  ...  Participated in CXC Cal/Ops RMF discussion group.  Agenda included
software implementation of the contamination spatial distribution and
a progress report on the CXC Cal CTI correction calibration.

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


4. OCC Support

  ...  Attended FOT review.

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.

  ...  Began planning for a possible move of the ACIS EGSE setup to a new
location at the OCC. 

Outreach:

None


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