From: Joachim Vollaire (joachim.vollaire@cern.ch)
Date: Thu Oct 11 2007 - 23:38:00 CEST
Hi Jason
Neutrons you transport in your simulation are the ones you will score in your USRBIN detector if you request neutron fluence. A way to change this is to write a user routine: fluscw.f in this case and activate a call to this routine using USERWEIG card (see chapter 13 for details). You can then define boundaries and then multiply the scored values by zero if the neutrons is outside the boundary or by one if inside the range of interest. . You could use USRICALL to define your boundaries or any other type of logic (SDUM of USRBIN....) .
For your particular case, you may also consider the definition of a fictious regions and use USRTRACK cards to obtain energy dependent spectra.
I would avoid playing with PAR-THR for scoring since you may "kill" neutrons which may contribute to your detector response (n,g ...., fission depending on your application)....
Hoping it helps
Joachim
________________________________
From: owner-fluka-discuss@mi.infn.it on behalf of Jason Crawford
Sent: Thu 10/11/2007 11:07 PM
To: fluka-discuss@fluka.org
Subject: Question for setting USRBIN energy threshold
Hello, I have had some difficulty using the FLUKA-discussion board so I
am posting these questions again. My questions are likely very simple
for an experienced FLUKA user.
I am using the USRBIN to calculate neutron fluence (mapped in bins) in
an area surrounding my detector, and I would like to know what, if any,
are the limits on maximum/minimum energy of the neutrons being counted?
In other words, if there are energy thresholds for this detector, what
are they and how can I change them? If not, how can I set the
mimimum/maximum neutron energies I wish to detect? I have tried using
the PART-THRes card to set a maximum energy, but this had no effect on
my results. I am also unclear as to how low energy neutron transport
ties in to this. For no threshold, I believe my input and simulation
calculations are correct. I would greatly appreciate any advice as to
how I should proceed.
Thank you,
Jason Crawford
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