Minutes 10/18/2000

Present: Heather, Ian, Joanne, Pat, Richard, Taka, Thomas, Toby, Traudl

GEANT4 for Balloon Flight

Taka  described the status of the GEANT4 simulation for the upcoming balloon flight.  See http://www.slac.stanford.edu/~handa/beamtest/geant4/geant4_101700.pdf for details (and a very nice picture).  Among the points made:

• GEANT4 outputs hit information only.  Digitization/readout will be (is?) done as a separate step.
• random number seed for each event is saved so that anyone may duplicate the event
• geometry description is based on Tracker.xml and other documentation sources, but current implementation is to hard-code parameters.
• planned improvements include elaborating geometry to include balloon components, etc., and adding to calorimeter output.
• additional work is needed to produce output in Root format and to improve the cosmic ray generator.  (Richard suggested consulting with Dave Thompson on the latter.)
• an installation of GEANT4 and the associated simulation work (Linux only) is available at SLAC.  An announcement will be made shortly.

Traudl warned that GEANT4 is not of production quality yet.  However, we believe it will be by the  time we require it to be, and in any case since we don't require precision hadronic calorimetry we are less sensitive than other experiments to deficiencies.

There was a request for documentation of how the GEANT4 simulation handles energy deposition in passive (not read out)  materials, to be compared with Toby's plan for Gismo.

There was some discussion of whether we can integrate Gaudi with GEANT4 in time to be used for the balloon flight.  It is seeming likely, but not certain.  Is it time to "freeze" the Gismo simulation? Richard pointed out that we have to have a fallback position and an agreed-upon date when we will fall back if Gaudi/GEANT4 is not ready for the balloon flight.  We need to enumerate and assign the subtasks involved in supporting the balloon flight with Gaudi/GEANT4.

Core Software Status

See  http://www-sldnt.slac.stanford.edu/glast/meetings/core_status20001019.htm for details.

Among the topics mentioned were changes/simplifications in progress to the application package.  These conflict with changes Joanne is making for the conversion to the new xml parser, so Toby and Joanne will work something out to get everything merged properly.

Package Monitor Web Page

Thomas has made some improvements to

http://www.slac.stanford.edu/exp/glast/ground/software/LatestPackages (a page automatically generated daily, listing for each Glast package who owns it and what the latest tagged version is)  and more were suggested:

• For each package add a hyperlink to the corresponding CVSweb page
• For each package add a hyperlink to a short overview/description of the package.  Preferably the target should already have been generated by Doxygen as part of the standard documentation process for packages. 

Administrative Matters

Richard mentioned several:

• We now have unix-served web space at http://www.slac.stanford.edu/exp/glast/ground/
• We have NT-served web space at http://www-glast.slac.stanford.edu/
• An offer is on its way to Karl Young.

J.Bogart Last Modified: 06/01/2010 15:45