[fluka-discuss]: USRBDX part/pr error?

From: hakan akyildirim <hakanakyildirim_at_sdu.edu.tr>
Date: Tue, 3 Dec 2013 11:38:09 +0000

Dear FLUKA users;

Recently, I have been studying on the PHOTONUCLEAR absorption cross sections of Carbon-12 and Oxygen-16 at 10-30 MeV photon range. I have realizad that, for some energy values, my USRBDX estimator (one way current) gives 0.0000 part/pr But when I increase or decrease the energy in a very small amount, the result differs from 0.0. For example,

E_gamma=13.0E-2 => part/pr=0.0000 BUT E_gamma=12.999E-2 => part/pr=9.9999960E-1
E_gamma=14.75E-2 => part/pr=0.0000 BUT E_gamma=14.75001E-2 => part/pr=9.9999990E-1

I guess, since 13.0E-2 MeV is "almost" equal to 12.999E-2 MeV, the resultant part/pr value will "almost" be the same. But I wonder what the reason is for such a situation. Is it a bug or a rounding matter?

Many thanks.

Dr. Hakan AKYILDIRIM
University of Süleyman Demirel
Dept. of Physics/Nuclear Physics
TURKEY
Received on Tue Dec 03 2013 - 14:32:16 CET