Material Definitions

Media in Geant need to be defined in terms of the properties when interacting with different sorts of radiations. This is done in two places in the program: Materials, which are needed by more than one detector, are defined in one central place in the routine DEFMED. These definitions do not depend on the specifics of the detector.

Materials which are used by one detector only, which are specific to this detector, are defined in a detector routine DETMAT for detector DET. Some properties of these materials might be defined through special detector dependent parameters. If so a routine DETGEOM needs to be called before DETMAT.

At the moment all detectors inside the coil are assumed to be immersed in a constant magnetic field of $3 T$. A uniform magnetic field is defined in the opposite direction for materials outside the coil used in the outer detectors, and the magnitude is given by the ratio of areas inside and outside the coil (assuming simple flux conservation, in a very naive way). Materials used in the definition of the beamline are treated in a more complicated way to properly describe the magnetic fields inside the different beamline elements. At present there is no special treatment of the magnetic field in the end-caps.