ACIS Instrument Support - Monthly Progress Report for November 2002

1. ACIS Characterization

1.1 Characterize and model radiation damage in ACIS CCDs

  ...  Continued running charge injection tests on I0 from the command
load.  Accumulating more statistics and more energies with three data sets.

1.2 Design and characterize alternative CCD readout modes

  ...  Supported charge injection tests on-board with lab verification and
testing.  Determined new set of DAC values for use with upcoming tests on
S2.

1.3 Monitor scientific on-orbit performance of ACIS

  ...]  Presented analysis of ACIS performance evolution for Chandra Calibration Workshop.  Viewgraphs available at http://cxc.harvard.edu/ccw/proceedings/

  ...  Continued analysis of ExtCalSrc data to search for putative QE
decrease at low energies.  Continued searching for spatially varying QE,
motivated by the temperature gradient across the filter.

  ...  Continued monitoring of ACIS CTI.  No significant changes beyond the
long term slow increase.  (http://space.mit.edu/~cgrant/cti/)

 [...  Evaluating the correlation of the Chandra Radiation Model fluence
with CTI increase.  New CRM numbers for mission will be available in
early December.

  ...  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.


2. Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance.
Review of the past 60 days of engineering housekeeping shows no anomalous
trends.

  ...  Continue to support thermal monitoring of the PSMC

 [...] Continuing assessment of possible bakeout scenarios included
potential risk to the instrument.

2.2 Flight software maintainence

  ...  ACIS flight software patches in-house review conducted on August 6
(Rev C).  Addressing reviewer comments and recommendations.

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

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

 [...] Participated in ACIS science operation team meeting

3. CXC Support

3.1 Provide user support

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

 [...] Supported investigation of CXC help desk ticket regarding 
possible calibration uncertainties by providing assessment of
CTI and background during observation.

3.2 Provide data analysis support

 [...] Participated in Chandra Calibration Workshop

 [...] Participated in CXC Cal/Ops RMF discussion group.

 [...] Replied to question from CXC SDS about using corner pixel
values for bias subtraction.  Primarily useful for solar system
objects with high optical loading on the CCD.

  ...  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


Outreach:

Two presentations at Chandra Calibration Workshop
   talk by Bautz: "ACIS Science and Calibration"
   talk by Grant: "Evolution of ACIS Charge Transfer Inefficiency"