Speaker
Dr
Patricia Mendez Lorenzo
(CERN IT/PSS)
Description
Geant4 is a general purpose toolkit for simulating the
tracking and interaction of particles through matter. It is
currently used in production in several particle physics
experiments (BaBar, HARP, ATLAS, CMS, LHCb), and it has
also applications in other areas, as space science, medical
applications, and radiation studies.
The complexity of the Geant4 code requires careful testing
of all of its components, especially before major
releases (which happens twice a year, in June and December)
including detailed regression testing on complex
configurations.
We describe the recent development of an automatic suite for
testing physical processes in high-energy
calorimetry. The idea is to use a simplified set of hadronic
calorimeters, with different beam particles at, several
beam energies, and comparing relevant observables with the
reference version of Geant4. Only those
distributions that are statistically incompatible are then
printed out and finally inspected by a person to look for
possible bugs. The suite is made of Python scripts, and
utilizes the "Statistical Toolkit" for the statistical tests
between pair of distributions, and runs on the Grid to cope
with the large amount of CPU needed in a short period
of time. The total CPU time required for each of these
Geant4 release validation productions amounts to about4
CPU-years, which have to be concentrated in a couple of
weeks. The Geant4 team has already run four of them,
starting in December 2004. From December 2005 they run as
Geant4 VO demonstrating the full involvement of
Geant4 inside the EGEE communities. Several EGEE sites have
provided them with the needed CPU, and this has
guaranteed the success of the production, arriving to an
overall efficiency rate of about 99%.
We report the Geant4 experience in using the Grid, and in
particular the results obtained during the last
production (June 2006). During that production we used the
Ganga/Diane framework developed by the ARDA
group at CERN was used for. the 10% of the production with
very promising results. The next production
(December 2006) will be fully executed using this framework
and we present the present status of the
preparation.
Primary authors
Dr
Alberto Ribon
(CERN Ph/SFT)
Dr
Jakub Moscicki
(CERN IT/PSS)
Dr
Massimo Lamanna
(CERN IT/PSS)
Dr
Patricia Mendez Lorenzo
(CERN IT/PSS)
