Re: [fluka-discuss]: Implementation of Beam spectrum by SOURCE

From: Francesco Cerutti <Francesco.Cerutti_at_cern.ch>
Date: Mon, 2 Oct 2017 12:05:53 +0200

Dear Agnieszka,

are you interested in decay alphas? Or photons and electrons?
The latter ones can be directly obtained - all along the decay chain - by
implementing in the input file your Ra isotope as radioactive source
(BEAM/SDUM=ISOTOPE, HI-PROPE with respective Z and A, RADDECAY/WHAT(1)=2.0
i.e. semi-analogue), with no need for the source user routine.

Conversely, for the alphas - with the present FLUKA version - you actually
need to implement your source.f, which is more challenging.

3. source.f requires several variables (weight, polarization, ...) to be
set, but they are already filled by default, so you shall change only the
ones relevant to your case (i.e. the particle kinetic energy/momentum)

2. decay spectrum data are available for instance at
http://www.nndc.bnl.gov/
An external file can be in whatsoever format, since it's up to you to
properly read its content inside source.f and appropriately store the
relevant info.

1. if you are interested in sampling decay alphas, you should set in the
BEAM card 4-HELIUM as beam particle and assign in source.f its
kinetic energy and momentum according to your data, selecting a fixed
experimental energy value on the basis of the respective branching ratio.
This requires some programming skills.

Kind regards

Francesco

**************************************************
Francesco Cerutti
CERN-EN/STI
CH-1211 Geneva 23
Switzerland
tel. +41 22 7678962
fax +41 22 7668854

On Sun, 1 Oct 2017, Agnieszka Witkowska wrote:

> Dear Fluka Users,
> I am the beginner in terms of Fluka usage and I am trying to implement spectrum of radium
> as a beam by using user routine source.f. I have read manual and Fluka courses
> presentations, however it is still not clear for me how to implement such feature. Can You
> please help me with questions below?
>
> 1. How to assign beam to the data read from the file?
> 2. Can You please advise where can I find files with spectrum properties? As I understand
> files which can be included in source routine should be in collision type?
> 3. I would like to modify only the energy of the beam to create spectrum as a source. Do I
> have to include in the source routine other  parameters definitions like weight of the
> particle, polarization etc. or I can omit them and the routine will work?
>
> Thank You for your help in advance.
>
> Best regards, 
> Agnieszka Witkowska
>
>

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Received on Mon Oct 02 2017 - 13:34:00 CEST

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