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Rob Veenhof, NIKHEF (Amsterdam, the Netherlands)
Garfield is a computer program originally written for the detailed simulation of two-dimensional drift chambers. The PaRC service has taken over the production of executables at CERN. The following article describes the list of modifications since the latest official release (previous releases have been described in past CNL articles).
SOLIDS, has been added which can be
used to define the 3-dimensional objects present in the chamber
in case the field is derived from a field map.
Entering these objects is not mandatory, but is helpful when
studying collection efficiencies, computing calibration curves
and signals.
Some commands like RESET have been modified
in line with the addition of the SOLIDS command.
It is hoped that this information can in the future be derived
from files produced by the finite element programs.
AREA which now accepts
a considerably extended argument list.
PARAMETERS statement and are taken into account
when performing Monte Carlo drift line integration for ions.
The diffusion coefficients are for the time being assumed not to
depend on the field, but this limitation can be lifted if needed.
The TEMPERATURE and PRESSURE statements
now accept a unit following the temperature and pressure.
The latter, for instance, can therefore be entered in more common
units like the atm or the hPa rather
tha in Torr.
Steve Biagi has released a Monte Carlo version of Magboltz which
should have a substantially higher accuracy.
An interface with this program is being written - meanwhile,
interested users should contact
Steve Biagi/University of
Liverpool
(sfb@hep.ph.liv.ac.uk)
directly.
AREA command as in the field section
has been introduced here.
PLOT_TRACK and PLOT_DRIFT_LINE
has been modified to match the new projection scheme.
Procedures for drifting negatively charged ions have been added.
A procedure that integrates the charge contained in a cylindrical or spherical area has been added. There is now also a procedure that computes the flux of the electric field through a parallelogram.
Intrinsic functions called MINIMUM and MAXIMUM
have been added.
They operate on histograms and matrices and return the minimum and the
maximum number of entries or value of the argument histogram or matrix.
/afs/cern.ch/project/parc/bin/garfield.
For further information, please contact
Parc.Support@cern.ch or
Juan Manuel Guijarro
(Juan.Manuel.Guijarro@cern.ch).
http://consult.cern.ch/writeup/garfield.
Cnl.Editor@cern.ch