The file(s) contain descriptions of the different parts of the detector, as follows :
TYPE: (detector_type) LAYER: (layer_name) (REPEAT : TIMES=value, geometry parameter step=value,...) GEOMETRY:(geometry parameter=value,geometry parameter=value,...) MATERIAL:(material parameter=value,material parameter=value,...) MEASUREMENT:(measurement parameter=value,measurement parameter=value,...) (ENDREPEAT:) LAYER: . . .Followed by the next detector type, etc.
Any number of empty lines can be inserted in the file, and any line beginning with the characters 'C', 'c', '*' or '!' are treated as comments, and are ignored.
TYPE should be one of BARREL_TRACKING, FORWARD_TRACKING, BARREL_CALORIMETRY, FORWARD_CALORIMETRY, BARREL_TAGGERS, FORWARD_TAGGERS, BARREL_SCINTILATORS, or FORWARD_SCINTILATORS.
The REPEAT function makes it easy to describe repeated layers that only differs by their geometry, and only does so by a constant step. The layer-name, as well as the measurement and material parameters are identical for all layers described by this construction, but the selected geometry parameters are incremented by the step given.