Re: Proton scattering

From: Giuseppe Battistoni <>
Date: Fri, 17 Sep 2010 14:58:01 +0200 (CEST)

Dear Antonello
I have been working a litte bit on your case.
I can confirm that it is very likely that there are the two components
that you mention (elastic and inelastic).
In FLUKA you cannot (and must not) switch off one of the two, but you can
select the output.
In order to do that you have to make use of a user routine prepared for
advanced users: mgdraw.f (see USERDUMP command in the manual) and activate
there the entry called USDRAW.

There, in a given region, for each secondary particles, you can access a
code specifying the origin of the particle. In particular:
100 is elastic interaction secondary
101 is inelastic interaction secondary.

In this way in principle you can build a logic (maybe other user routines
are necessary) to prepare a user defined output.
For instance you can think of a simple ascii files of particles with
energy and angle and interaction code, when
exiting from a given region (see entry BXDRAW of mgdraw.f) that
you can read with an external analysis code (from your image I guess
that you are using Root...).

It requires some study and some work, but I often did similar things.
I attach here to help you the mgdraw.f that I used to investigate your
case, together with the modified input. There (in mgdraw) I put some
simple WRITE statements on unit * (i.e. the .log file !!) so you can
see yourself what happens

For instructions to build the executable with user routines see the
FLUKA manual and Flair documentation

 All the best

Giuseppe Battistoni

PS you can also swith off e.m. particles with EMF-OFF plus DISCARD of
electrons and photons: at this level they might be a nuisance and a waste
of time

On Wed, 8 Sep 2010, Antonello Carloni wrote:

> Dear Fluka users,
> in my simulation, apart from the rest of the geometry regions to which I chose
> to assign vacuum so as not to have interactions , I have a simple 65 MeV
> pencil-like beam interacting only with a slab of Kapton, (region BRA in the
> file) 5Ám thick and placed at a distance of about 5.1 mm from the source.
> The only detector that i placed is a one way scoring USRBDX detector, made of
> vacuum and subdived into linear binning in energy and angle from 0 to 0.24
> steradians and from 64.3 to 65 MeV in energy.
> This detector is placed at a distance of 25 cm from the beam source..
> Herewith attached you can see the plot that i obtained.
> What i would like to konw from you is if it is possible to ask FluKa to
> suppress the scattering parts which are clearly visible in the plot.
> I tried to with any effort but they keep on coming out on the graph.
> I pesonally think that those two components may be elastic and anelstic
> scattering of protons against nuclei and electrons.
> I also tried to suppress bremsstrahlung as you can see from the input file,
> but no succes....
> What would you suggest?!
> Thanking you in advance,
> Antonello Carloni
> Dipartimento Tecnologie Nucleari Per la Salute
> Infn-ISS

Received on Fri Sep 17 2010 - 15:36:04 CEST

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