Re: Understanding EMF-CUT and residual dose rate

From: <>
Date: Thu, 29 Mar 2012 10:29:04 -0700 (PDT)

Ok, thank you Alberto.

I think I understand now.

The default thresholds for e+/e- and gammas are "generated" depending on
various settings and not known a priori. One can find out what they are by
doing a short run and checking Ecut, Pcut, Ae, and Ap.

And anyone interested in residual dose rates must set both transport and
production cut-off energies.

Best wishes,

> Dear Mina,
> you say:
>> I am sorry but there is no where in the manual where I see a default
>> transport/production energy cut-off of 333 keV for photons and 1 MeV for
>> electrons.
> Read Note 1 to EMFCUT:
> "Default values are available for the electron and photon production
> thresholds in electromagnetic interactions, but they are generated by a
> complex logic based on possible other settings (transport cutoffs,
> delta-ray production thresholds, DEFAULTS card, other defaults)".
> A "complex logic" cannot be expressed in a simple way. To the user, it
> should
> suffice to know that many different things contribute to generate those
> defaults: "transport cutoffs, delta-ray production thresholds, DEFAULTS
> card,
> other defaults". Especially because the user is strongly discouraged to
> rely on those defaults: "It is not always guaranteed that the resulting
> values
> be appropriate to the problem of interest. Therefore, in order to have
> good
> control of the physics, the user is recommended to provide explicit
> threshold
> values, or at least to check them on the main output".
> I am sorry: it is true that in general defaults play a very important role
> in FLUKA and the user can take advantage of them. This is an exception.
> As far as I know, the only exception.
> Alberto
Received on Fri Mar 30 2012 - 13:40:44 CEST

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