Re: [fluka-discuss]: URSYELD unit of measurements

From: Francesco Cerutti <Francesco.Cerutti_at_cern.ch>
Date: Mon, 7 Apr 2014 00:00:05 +0200

no problem.

Just keep in mind that the double differential "cross section" you obtain
is such only in the presence of a thin target (as previously mentioned)
AND after your division by the beam interaction probability (transforming
the scored quantity from "per beam particle" to "per nuclear reaction"),
which under the first condition is equal to the ratio between the target
thickness (along the beam direction) and the beam particle inelastic
scattering length printed in the output file.

Kind regards

Francesco

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

On Fri, 4 Apr 2014, Francesco Rossetto wrote:

> Thank you very much, I saw something in the output files referring to a mb
> quantity, but I was not sure if the final result was expressed either in mb
> or cm2, since the centimetre is still the main length unit in Fluka. Thank
> you very much anyway, I'll pay more attention to the manual next time.
>
> Francesco
>
> Il 02/04/2014 17:16, Francesco Cerutti ha scritto:
>>
>> Dear Francesco,
>>
>> as written in the manual and reminded from time to time on this list, in
>> USRYIELD one should normally ask for double differential yield (in your
>> case resulting as [GeV-1 srad-1 per beam particle]) and not double
>> differential cross section, which unfortunately is the default choice but
>> has meaning only in case of a thin target, being just the aforementioned
>> yield multiplied by the nuclear reaction cross section (in [mb], as
>> specified both in the output file and in the _sum.lis file produced at
>> postprocessing) of beam particles at beam energy on the material selected
>> by the user in USRYIELD (possibly different from the target material).
>>
>> Cheers
>>
>> Francesco
>>
>> **************************************************
>> Francesco Cerutti
>> CERN-EN/STI
>> CH-1211 Geneva 23
>> Switzerland
>> tel. ++41 22 7678962
>> fax ++41 22 7668854
>>
>> On Wed, 2 Apr 2014, Francesco Rossetto wrote:
>>
>> > Dear Fluka users,
>> > could you please help me with a problem? I would like to use the card
>> > USRYELD in order to score the double differential cross section as a
>> > function of the lab angle and the kinetic energy of the emerging
>> > neutrons from a uranium target. I set the card as described in the
>> > instructions and Fluka runs and generates the output without any
>> > problem. The issue is how is expressed the output. Is it cm^2? Barns? Do
>> > I have to normalize the result by some quantity? Sorry for bothering
>> > you, but the manual gave me no clue about.
>> >
>> > --
>> > Francesco
>> >
>> >
>>
>
> --
> Francesco
>
>
>
Received on Mon Apr 07 2014 - 01:10:36 CEST