CERN Program Library Long Writeup W5013 - CERNLIB ...

Geant 3.21 GEANT User’s Guide AAAA001
Origin : Submitted: 01.10.84
Revision : Revised: 20.04.94
Documentation :
Foreword
As the scale and complexity of High Energy Physics experiments increase, simulation studies require more
and more care and become essential to
• design and optimise the detectors,
• develop and test the reconstruction and analysis programs, and
• interpret the experimental data.
GEANT is a system of detector description and simulation tools that help physicists in such studies. The
GEANT system can be obtained from CERN as six Patchy [8]/CMZ [9] files: GEANT, GEANG, GEANH, GEANF,
GEANE and GEANX. The program runs everywhere the CERN Program Library has been installed 1 .
The GEANT and GEANG files contain most of the basic code. The GEANH file contains the code for the hadronic
showers simulation from the program GHEISHA [1]. The GEANF file contains the source of the routines for
hadronic showers development from the FLUKA [2, 3, 4, 5, 6, 101, 102] program which is interfaced with
GEANT as an alternative to GHEISHA to simulate hadronic cascades. The GEANE [11] file contains a tracking
package to be used, in the context of event reconstruction, for trajectory estimation and error propagation.
The GEANX file contains the main program for the interactive version of GEANT (GXINT) and a few examples
of application programs which may help users to get started with GEANT.
General information concerning GEANT, for example access to the source code, the list of problems and
their proposed corrections, the context of utilisation on the CERN machines, the status of some application
programs, the acquisition of documentation, etc., are kept up to date through CERN news and InterNet
news group (cern.lgeant) and an electronic mailing list which is installed on the CERN IBM mainframe
(BITnet/EARN node CERNVM). The name of the list is LGEANT (see below how to subscribe).
The first version of GEANT was written in 1974 as a bare framework which initially emphasised tracking
of a few particles per event through relatively simple detectors. The system has been developed with some
continuity over the years [12]
New versions may differ from the previous ones. Some of the modifications may lead to backward incompatibilities.
The user is therefore invited to read carefully the Patch HISTORY of the current GEANT file where
all changes are described in detail.
The development and the maintenance of GEANT are possible only thanks to the devoted and continuous
collaboration of physicists around the world who use the program and contribute their feedback to the
authors and maintainers at CERN. It is of course impossible to mention all of them, and new names are
added frequently to the list of the contributors. The GEANT team wish to thank them all and expresses its
hope that they will continue to help us.
GEANT version 3 originated from an idea of René Brun and Andy McPherson in 1982 during the development
of the OPAL simulation program. GEANT3 was based on the skeleton of GEANT version 2 code [12].
In close collaboration with René and Andy, Pietro Zanarini developed the first versions of the graphics
system as well as the early versions of the interactive package initially based on ZCEDEX, then upgraded to
KUIP.
1 At the moment of writing these are the systems on which the CERN Program Library is maintained: VM/CMS-HPO-XA-
ESA, SUN, Silicon Graphics, CRAY Y-XMP, Apollo 3000 series, Apollo 10000, HP 400 series, HP 700 series, IBM RS/6000,
IBM AIX/370, VAX/VMS, Alliant, Dec Ultrix, NeXT, IBM MVS-HPO-XA-ESA, Convex, MAC/MPW (partial implementation),
PC-DOS, PC-Linux, PC-Windows/NT.
5 AAAA001 – 1