Building Detector Components

The detector geometry is defined in two steps: a routine DETGEOM fills the appropriate common blocks with dimensions etc. In general the relevant common blocks are DETDIMS. A routine DETBLD then builds the actual detector. As an example, if the user wants to include the TPC the following routines are needed:

• TPCGEOM: to define the dimensions etc of the TPC
• TPCMAT: defines the TPC specific materials (gas etc. )
• TPCBLD: builds the actual geometry via calls to GSVOLU, GSPOS etc.

Switching on and off of a subdetector is defined with the FFREAD cards TURNON (see above).