Dear Anton,
first of all thanks for your clarification.
The need for the collision tape relies on the following:
1. In my geometry, I am asked to score all the particles emerging from
a boundary crossing, in their position, momentum, energy etc.
2. As I verified by means of USRBIN and USRBDX, very few of some
particles (pi, mu, e-) do come accross the boundary. But in that
case the way I mentioned in the first email, allowed me to overcome
the problem and plot a spatial distribution quite easily.
3. Now that I need the collision tape file, I was wondering about being
able to score even one of those particles, with associated
statistical weight, if the number of primaries is not sufficient .
4. The collision tape is needed in order to perform subsequent analysis
on a detector by means of root, but this specific topic will not
fall within my business. That's why I would have preferred to get
only one file. Don't know how, say 100 tape files from 100 cycles,
could be a) useful to score those rare events and b) easy to manage
for my collegues.
We will discuss on that.
Thanks again, cheers
Oscar
Oscar Frasciello, PhD
Radiation Protection Group
Istituto Nazionale di Fisica Nucleare
Laboratori Nazionali di Frascati
Via Enrico Fermi 40
00044 Frascati (RM) Italy
Tel. office: +39 06 9403 2104
Tel. Tenocode: +39 06 9403 8114
Fax FISMEL: +39 06 9403 2364
email: oscar.frasciello_at_lnf.infn.it
Il 14/07/2017 10:10, Anton Lechner ha scritto:
> Dear Oscar,
>
> There is a fundamental difference between a scoring a la USRxxx and a
> collision tape:
>
> 1) When using a USRxxx scoring you don't store information for each
> individual event but you populate a spatial mesh or a histogram. In
> this case, it is essential to merge results from different cycles as
> this is the only way that FLUKA will provide you an error estimate for
> the bin entries.
>
> 2) In case of a collision tape, you store specific information about
> each individual event, and it is up to the user to post-process the
> data according to his/her needs (this requires evidently some
> customized user code - in Fortran or whatever language/package you
> want to use). In this sense, simply merging collision tape files from
> different cycles into one file, i.e. simply appending the output of
> cycles one after the other, would be rather a cosmetic process
> (contrary to merging USRxxx files, where the average+error is
> calculated from the different cycles). Apart from that, FLUKA cannot
> provide a general script to merge the output from modified mgdraw
> routines since the output will look different in all cases.
>
> May I ask why you need to have all the collision tapes in one file? I
> would rather write a post-processing program, which reads in
> individual collision tapes from different cycles and performs the
> necessary arithmetic.
>
> Cheers, Anton
>
>
> ------------------------------------------------------------------------
> *From:* owner-fluka-discuss_at_mi.infn.it
> [owner-fluka-discuss_at_mi.infn.it] on behalf of Oscar Frasciello
> [oscar.frasciello_at_lnf.infn.it]
> *Sent:* 12 July 2017 14:39
> *To:* fluka-discuss_at_fluka.org
> *Cc:* Oscar Frasciello
> *Subject:* [fluka-discuss]: merging multiple collision tape files
>
> Dear FLUKA experts,
> dealing with "large" runs (billions of primaries) I usually split them
> in multiple runs with less primaries through the "spawn" option in
> flair (as many as the available physical cores on the dedicated
> server), then merging the output of the specific scoring cards
> (USRXXX). So being able to reach the desired statistics in a more
> reasonable amount of time. Now I am using a modified mgdraw.f routine,
> getting the desired collision tape file with requested informations.
> And the test run (very few primaries, ~1E3) does work the expected
> way. But it seems to me it is not possible to proceed the same way
> with the n-collision tape files, i.e., it is not possible to merge
> them from the n cycles' output.
>
> Do you confirm this? Do I need to run one single core cycle with the
> necessary number of primaries (~1E9)? Do you have any suggestion?
>
> Thanks in advance for your time and valuable support.
>
> Best regards,
> Oscar
>
> --
> Oscar Frasciello, PhD
> Radiation Protection Group
> Istituto Nazionale di Fisica Nucleare
> Laboratori Nazionali di Frascati
> Via Enrico Fermi 40
> 00044 Frascati (RM) Italy
> Tel. office: +39 06 9403 2104
> Tel. Tenocode: +39 06 9403 8114
> Fax FISMEL: +39 06 9403 2364
> email:oscar.frasciello_at_lnf.infn.it
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Received on Fri Jul 14 2017 - 13:09:50 CEST