Representative array configuration files for Cycles 1 and after are linked to from the "CASA Simulator and Configuration Files" section of the Tools page in the ALMA Science Portal. Configuration files for Cycle 0 are available from the Cycle 0 Documentation page. We recommend using these configuration files for detailed investigations and simulations.
However, for convenience, some configuration files are available in several versions of CASA. The location of the files in a given CASA installation can be found using this command at the CASA prompt (also accessed through the inline help for the CASA tasks simobserve and simalma):
os.getenv('CASAPATH').split(' ')[0] + '/data/alma/simmos/'