#Set of GPS commands that can be used to define a beam impinging on
#the crystal (provided that /gun/UseGPS true). 
#this macro can be also called from a dedicated menu of the GUI.

#beam
/gps/particle e-
#coordinate distribution
/gps/pos/centre 0 0 -30 mm
/gps/pos/type Beam
/gps/pos/sigma_x 1.0 mm                    
/gps/pos/sigma_y 1.0 mm                 
#angular distribution
/gps/ang/type beam2d
/gps/ang/rot1 1  0  0
/gps/ang/rot2 0 -1  0
/gps/ang/sigma_x 1.E-6 rad
/gps/ang/sigma_y 1.E-6 rad
#energy distribution
/gps/ene/mono 2.86 GeV