USRYIELD card normalization

dear all,

i run a simulation for two USRYIELD card but the distributions are different.

BEAM -0.02 0.0 0.0 1.0 0.0 HEAVYION
HI-PROPE 18. 40.

* x1 = LET , x2 = Ekin, material Silicon, d2N/dx1dx2
USRYIELD 123. BEAMPART -43. R6 R7 1.UsYld1
USRYIELD 880. 840. 500. 0.8 0.0 1403.&

* x1 = LET , x2 = Lab. Ekin/nuc, material Silicon, d2N/dx1dx2
USRYIELD 2623. BEAMPART -43. R6 R7 1.UsYld2
USRYIELD 880. 840. 500. 0.02 0.0 1403.&

i guess the reason is due to normalization factors.
but how can i know what normalization factors they are multiplied?

in the attached the plot you will see the difference.
are the axes labeles correct?

by the i use different way of calculation of LET in usreou.f routine

      ...
* range in silicon (cm)
      rsil = sqrt((xfsil-xisil)**2 + (yfsil-yisil)**2 +
     + (zfsil-zisil)**2)

* deposited energy in silicon (GeV)
      edsil = (eisil-efsil)

* LET (Linear Energy Transfer) (MeV/mg/cm2)
      elet = edsil/(rsil*2.33)
      ...

so how can i compare these results with USRYIELD card results?
ciao
e.

ps: thanks to Francesco for guiding to some points.

(note that m(40Ar)=37.215534... GeV and m(12C)/12=0.9312389... GeV)

==============================
  Ercan Pilicer
  Uludag University, Turkey
  High Energy Physics Department
==============================