Minutes of Technical Forum @ TRIUMF
(Draft 1.1 - Oct.02 M.Asai)

15:30 - 17:30, September 5th, 2003 (Friday)
The TRIUMF auditorium


[1] Recent and current developments (J.Apostolakis)
 http://www.triumf.ca/geant4-03/techforum/
 Geant4-Recent-and-Upcoming-Developments.ppt

[2] Release plan (G.Cosmo)
 http://www.triumf.ca/geant4-03/techforum/features.ppt

[3]Discussion on new requirements

[3.1] Requirements on new functionalities

Req.0101 Access to the Track properties before the processes
 Requester : G.Santin (ESA/ESTEC) 
 Responsible G4 developer : H.Kurashige

 Requested additional access method before DoIt() invokation for all 
processes was evaluated as likely to create performance overhead. 
Hisaya recommended using a wrapper class for use with any process. 
(action TBD)
Hans-Peter proposed to add new option in the hadronic processes to 
enable this for hadronic processes ? which is expected to have only 
small performance impact for typical use cases.

Req.0102 Development of X-ray surface processes
 Requester : G.Santin (ESA/ESTEC) 
 Responsible G4 developer : P.Gumplinger

 Peter will remain in contact with Giovanni Santin for collaborating 
in the development.

Req.0103 Geometry construction: input from external models
 Requester : G.Santin (ESA/ESTEC) 
 Responsible G4 developer : G.Cosmo

 Several potential developments were presented, but a relative
priority was not established, as well as concerning resources
to be assigned to them for possible future projects.
 A discussion at the architects forum and Steering Board will be
brought forward.

[3.2] Requirements on robustness / testing / validation

Req.0104 Ensure that events are reproducible between debug and 
 optimized modes
 Requester : F.Ranjard (CERN/LHCb)
 Responsible G4 Developer : J.Apostolakis

 Observations: Some Unix compilers (eg Sun) appear to provide such 
consistency between debug and optimized modes. However the 80-bit 
hardware of the FPU of x86 contrasts with the size of doubles stored 
as 64-bits in memory. Changes in storing of intermediate results 
can thus lead to small differences in the results, summing up until 
they can influence a Monte Carlo choice.
 Another source of differences is the initialization of variable in 
debug mode. Such changes should be detected using appropriate tools 
(eg valgrind) and fixed.
 Actions: Investigate use of combined (-g -O on Linux GNU-GCC) for 
addressing underlying debugging issues. (LHCb)

Req.0105 Handle unexpected conditions more robustly
 Requester : F.Ranjard (CERN/LHCb)
 Responsible G4 developer : J.Apostolakis

 Due to lack of complete information this was not addressed. It was 
postponed until the next forum.

Req.0106 Setup statistical test suite for most sensitive physics quantities
 Requester : R.Debois (SLAC/GLAST), et.al.
 Responsible G4 developer : J.Apostolakis

 It was well understood that Geant4 should establish a statistical test 
suites for Geant4 releases, extending the current testing undertaken at 
different development stages. John Apostolakis will organize a task force 
inside the collaboration in the coming weeks. It is clear, however, that 
with the limitation of finite resources, it is impossible to cover all 
physics use cases and the effect of all physics processes at all energy 
range or materials. The collaboration encourages users to undertake their 
own acceptance testing for their particular use and domain. 
 The collaboration noted positively the user communityfs wish that it should 
publicize its test suite, for the use of users themselves.

[3.2] Requirements on user support

Req.0107 Installation kit which contains all packages
 Requester : B.Arjomandy (Loma Linda University Medical Center)
 Responsible G4 developer : G.Cosmo / G.Folger

 Because of the copyrights and the large variety of potential installations, 
it is not easy to put everything into one piece.
The Geant4 collaboration undertook to study changes to ease installation and 
its instruction to the degree possible.

Req.0108 Creation of user group / discussion forum in medical field in 
 particular in dosimetry
 Requester : E.Brauer-Krisch (PSI), et.al.
 Responsible G4 developer : M.G.Pia

 Possibility of having new threads in HyperNews is discussed.
Also, it was agreed that Geant4 collaboration should promote any possible 
information exchange among users.

[4] Action list, summary and next Forum (M.Asai)

 Next proto Technical Forum will be held at CERN on October 7th. John 
Apostolakis will make an announcement with details.