#test beam
/gps/pos/type Plane				
/gps/pos/shape Circle
/gps/pos/radius 1. mm	
/gps/pos/centre 0. 0. 0. mm	
/gps/direction 0 0 1  	
/gps/particle gamma  
/gps/ene/type Mono					
/gps/ene/mono 20. keV