Dear Paolo,
the IONSPLIT option has been recently improved (since the FLUKA
version 2011.2x), in particular for what concern the meaning of the
parameters WHAT(4)-WHAT(6) in the PHYSICS card: they were not used
in previous versions of Fluka and I suspect that in your input files
you have the condition WHAT(6)=0, which is now deprecated.
The online manual was also recently updated and reads as follows:
For
SDUM
= IONSPLITting:
WHAT(1)
: flag for activating ion splitting into nucleons
< 0.0 : false, no ion splitting
= 0.0 : ignored
> 0.0 : true: ion splitting is activated
Default
= -1.0 (no ion splitting)
WHAT(2)
: minimum energy for ions (GeV/n) above which splitting into
nucleons will be performed
=< 0.0 : ignored
Default
= 0.1 GeV/n
WHAT(3)
: maximum energy for ions (GeV/n) below which splitting into
nucleons will be performed (default: 5 GeV/n)
=< 0.0 : ignored
WHAT(4)
: minimum ion mass for splitting (default: 2)
WHAT(5)
: maximum ion mass for splitting (default: 500)
WHAT(6)
: flag for the spliting algorithm
= 0.0 : deprecated since Fluka2011.2x (default)
= 1.0 : probability according to 1 - exp(- Ek/n / Emnspi)
where Emnspi=
WHAT(2)
and Ek/n is the kinetic energy
per nucleon of the current ion
= 2.0 : not implemented
= 3.0 : deuteron splitting performed at interaction
point computed according to a parameterized
formula, like 1.0 for heavier ions
You could try with these new settings.
Hope this helps.
Kind regards,
Andrea
On 24/01/2019 11:24, Paolo Giunio Pisano wrote:
>
> Good morning,
>
> I received two different Fluka input files used for activation
> calculations. If I try to run them as they are, the execution is
> terminated right away and I get the following message:
>
> Coalescence activated and beam above BME limit with no rQMD
>
> And no or incompatible IONSPLIT option!
>
> The problem is quickly solved if I switch on the IONSPLIT card (as
> suggested by the error message). However, it is my understanding that
> these two input files were running just fine (i.e. without IONSPLIT
> option) a few years ago (ca. 2013?). Is that possible? If yes, has the
> IONSPLIT option become strictly needed once the coalescence is
> activated in more recent versions of the code?
>
> From what I have read on the manual, the IONSPLIT option handles ions
> interactions by treating the nucleons one at the time and by
> superimposing their effects. Can someone, please, tell me if I should
> be careful in using this option or it is not expected to possibly
> affect the results in a negative way? Since I don’t really know the
> physics behind it and I cannot run the model without it, it is hard
> for me to get a feeling about it.
>
> Thanks in advance,
>
> Paolo Pisano
>
--
========================================================================
Dr. Andrea Fontana tel: +39 0382 987991
Istituto Nazionale fax: +39 0382 423241
di Fisica Nucleare
Sezione di Pavia e-mail: andrea.fontana_at_pv.infn.it
Via Bassi 6 web : www.pv.infn.it/~fontana
27100 PAVIA, Italy
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Received on Thu Jan 24 2019 - 17:14:19 CET