Responsible at CERN:
| Rob Veenhof | Created:
| 1 Sep 1984 |

Manual Type:
| User Guide | Last Update:
| 7 Sep 2010 |

Version:
| 9 | Verified:
| 7 Sep 2010 |

Author:
| Rob Veenhof | Valid until:
| further notice |

Reference:
| W5050 | Support Level:
| High |

Garfield is a computer program for the detailed simulation of two- and three-dimensional drift chambers.

Originally, the program was written for two-dimensional chambers made of wires and planes, such as drift chambers, TPCs and multiwire counters. For many of these configurations, exact fields are known. This is not the case for three dimensional configurations, not even for seemingly simple arrangements like two crossing wires. Furthermore, dielectric media and complex electrode shapes are difficult to handle with analytic techniques. To handle such increasingly popular detectors, Garfield is interfaced with the neBEM program. Garfield also accepts two and three dimensional field maps computed by finite element programs such as Ansys, Maxwell, Tosca, QuickField and FEMLAB as basis for its calculations. The finite element technique can handle nearly arbitrary electrode shapes as well as dielectrics.

An interface to the Magboltz program is provided for the computation of electron transport properties in nearly arbitrary gas mixtures. Garfield also has an interface with the Heed program to simulate ionisation of gas molecules by particles traversing the chamber.

Transport of particles, including diffusion, avalanches and current induction is treated in three dimensions irrespective of the technique used to compute the fields.

The program can calculate for instance the following:

- field maps, contour plots and 3-dimensional impressions;
- the wire sag that results from electrostatic and gravitational forces;
- optimum potential settings to achieve various conditions;
- plots of electron and ion drift lines;
- x(t)-relations, drift time tables and arrival time distributions;
- signals induced by charged particles traversing a chamber, taking both electron pulse and ion tail into account.

- help facility with examples for nearly every command, which can be consulted from within the program and via WWW
- technical notes on specific areas of the program and on related topics
- bug reports
- examples that illustrate the use of the program
- CNL articles (up to 2000)
- news (from March 2005)
- running the program at CERN
- source files of the program

Last updated on 8/2/11.