Discrepancy in Energy Deposition Results Between MGDRAW and USRBIN

Advanced Features and User Routines
1

Dear FLUKA experts,

I am running a simulation with 1000 primary electrons interacting in a 1×1×1 cm³ water cube as a simple example to understand the differences in energy deposition calculations in the TARGET region.

I am using two methods to determine the energy deposition:

MGDRAW.F:
My customized MGDRAW routine logs energy deposition events to a file (1_Energy_Deposition_TARGET.dat). By summing the RULL values (which represent the energy deposited at each event), I obtain a total energy deposition of approximately 0.07116 GeV. This corresponds to about 7.116×10⁻⁵ GeV deposited per electron.

USRBIN scoring:
I also scored energy deposition in the TARGET region using the USRBIN card. The resulting output file (3_Target.dat) reports an energy deposition of about 0.00188348 GeV per electron.

I expected both methods to yield the same total energy deposition, but they differ significantly.

Could you please help me understand the origin of this discrepancy?
For your review, I have attached the following files:

MGDRAW routine:
mgdraw_dump.f (17.3 KB)
1_Energy_Deposition_TARGET.dat (57.0 KB)

USRBIN output: 3_Target.dat
3_Target.dat (29 Bytes)
exampl.flair (3.3 KB)
exampl.inp (1.5 KB)

Thank you in advance for your assistance.

Kind regards,

Zohrab

2

The RULL values of the ENDRAW entry of mgdraw.f account only for point-like energy deposition events. Energy deposition along charged particle tracks is stored in the DTRACK array available in the first part of the routine.

3

Thank you very much for the helpful information.

Thanks and regards
Zohrab