 Of a total of  25000 rays, of which   6250 formed the input set 
    174 were out of the mirror N.    4
 The mirror collects  0.97216     of the incoming flux.
 The average reflectivities are :
 S-pol                      0.87153    
 P-pol                      0.87152    
 Total                      0.87153    
 The overall efficiency of the mirror is : 0.84726    
