Re: [fluka-discuss]: role of RADDECAY in scoring isotope yields

From: Paola Sala <paola.sala_at_mi.infn.it>
Date: Tue, 13 May 2014 16:48:40 +0200

 From: Marco Grassi (&#39532;&#37239;) <"Marco>
Date: Tue, 22 Apr 2014 11:12:19 +0800

Dear Anna,
Dear Marco,
with an awful delay, I would like to come back to your question (original
mail below).
There is no time window in the simulation. If you select the semi-analogue
mode, the decays are randomly selected according to the lifetime of the
concerned isotopes.
To complement what Anna said, the RESNUCLEI scoring can also take into
account the decay products, if you issue a
DCYSCORE card with what(1)=-1. and assign it to selected RESNCLEI. in this
case, both prompt and decay residuals will be scored together.

If you wish, you can define by yourself time windows in your auxiliary
routines.
All particles, prompt and decayed, carry with them their "age" coded as
ATRACK in the TRACKR common. Atrack is in seconds, is counted from the
instant when the primary is started, and includes transport time.
There is also a flag to distinguish prompt and decay product: the logical
flag LRDDCY in the RDCYCM common is .true. for decay products. The values
in RESNUCLEI can be filtered through the comscw.f routine.
Hope this helps
Paola




 From: Marco Grassi (&#39532;&#37239;) <"Marco>
Date: Tue, 22 Apr 2014 11:12:19 +0800

Dear Anna,
thanks a lot for clarifying this issue. But now I have a doubt about the
way RADDECAY works.

Let's assume that RADDECAY is active in semi-analogue mode. When I see an
isotope in the RESNUCLEI score, it
means that it didn't decay during the time window assumed for the MC
simulation. E.g. 9Li (one of the isotopes
I'm interested in) has a ~180ms half life. If the simulated time window
was 5 seconds long, I should see no
9Li left in the detector, hence no Li9 in the RESNUCLEI score.

My impression is that the isotope yield that RESNUCLEI is scoring might be
strongly dependent on the time
window assumed by RADDECAY. Is this correct?

If this is the case, can you please quantify the length of such a time
window?

Thanks again,
        Marco

Paola Sala
INFN Milano
tel. Milano +39-0250317374
tel. CERN +41-227679148
Received on Tue May 13 2014 - 18:10:25 CEST