Re: Foil simulation Nikhef

(smtp1.mi.infn.it [192.84.138.69]); Thu, 12 Feb 2009 15:19:18 +0100 (CET)
Sender: owner-fluka-discuss_at_mi.infn.it

Hi Wout,

I few comments and observations:

- Ranges of region names always refer to the order they appear in the
geometry definition. Thus, since region 'Foil' comes before region
'Copper' the range in the first EMFCUT card doesn't make sense.

- Do you have a particular reason for requesting leading particle biasing
for compton and photoelectric effect (EMFCUT/What(3))?

- Since you upper scoring limit in USRBDX is 1MeV it will probably not
call fluscw for electrons of higher energy. Raise the scoring limit in
case you are missing something here.

- opening the data-file in fluscw on each call is probably wasting CPU.
If you want to make it more efficient open it at the first call only

       IF (LFIRST) THEN
          ...
          LFIRST = .FALSE.
       END IF

- apart from the above comments you should obtain all electrons with your
input/fluscw. Thus, maybe the low number is reality(?) Did you look at the
spectrum which you ontained with USRBDX?

Cheers
Stefan

On Thu, 5 Feb 2009 wkremers_at_nikhef.nl wrote:

> Hello Stefan,
>
> My Fluka simulation seems to be working now, but I still have one
> question. The produced amount of electrons is very low only about 12-15
> per 10000 10 GeV muons. It seems USRBDX only detects Delta Ray electrons.
> I was wondering if it was possible non - delta ray scattered secondary
> electrons as well, since these are what I'm interested in. Ive included my
> up to date files as an attachment,
>
> Thx for the help,
> Wout
>
> > Hi Wout
> >
> > First of all your copper layer has zero volume
> >
> > RCC Foil 0.0 0.0 0.0 0.0 0.0 -0.0065 1.05
> > XYP Cut -0.0065
> >
> > * Foil
> > Foil 5 ( +Foil +Cut )
> > * Copper layer
> > Copper 5 ( +Foil -Cut )
> >
> > I think you should move the Cut inside the Foil so that FLUKA indeed
> > recognises it as region and calls fluscw on passing the boundaries.
> >
> > Furthermore, just an observation: EMCUT/What(1) is total energy
> > (mass+kinetic). I would have to check what FLUKA is doing if total energy
> > is defined 1keV but its better to define it as kinetic energy (What(1)<0)
> > to be sure. You should also set the production cutoff equal to the
> > transport cutoff (1keV). The photon cutoff is comparably high. Are you
> > sure that you are not loosing secondary electrons this way?
> >
> > For checking which cutoff FLUKA actually used it is always useful to have
> > a look at the output. See
> > http://www.fluka.org/web_archive/earchive/new-fluka-discuss/1829.html
> > for further help.
> >
> > The delta-ray thershold is 10keV. Is this what you want?
> >
> > Cheers
> > Stefan
> >
> >
> > On Thu, 29 Jan 2009 wkremers_at_nikhef.nl wrote:
> >
> >> Hello Stefan,
> >>
> >> Ive setup an input, geometry and a modified fluscw.f file. The only
> >> problem is that I seem t get a value of zero for the electron currents,
> >> and the simulation finishes rather quickly, so i think I mightve
> >> forgotten
> >> something in my input file. Also ive setup fluscw.f so that it should
> >> only
> >> store data when USRBDX is called, but i still seem to be getting
> >> particles
> >> with different particle numbers, rather then just electrons. Ive
> >> attached
> >> the input, geometry and fluscw.f files. I would be very grateful if you
> >> could have a look at them, if you have the time,
> >>
> >> Thank you very much,
> >>
> >> Greetings,
> >> Wout
> >>
> >> > Hi Wout
> >> >
> >> > I think that meanwhile Markus has replied to your question (on
> >> > fluka-discuss). Let me know if there is anything remaining..
> >> >
> >> > cheers
> >> > Stefan
> >> >
> >> >
> >> >
> >> >
> >> > On Thu, 22 Jan 2009 wkremers_at_nikhef.nl wrote:
> >> >
> >> >> Hello Stefan,
> >> >>
> >> >> Im not sure if you remember me but I came by your room a few months
> >> ago
> >> >> asking about fluka. I wanted to simulate an electron or proton of a
> >> few
> >> >> GeV goin through a copper coated kapton foil, and see how many
> >> >> secondary
> >> >> electrons make it through to the other side. Ive setup my input file
> >> >> now,
> >> >> but Im not sure about the output. I havent edited the fluscw.f file
> >> to
> >> >> output all the electron data yet. I was wondering if you could have a
> >> >> look
> >> >> at the input file if you have the time.
> >> >>
> >> >> Thank you for your time,
> >> >> Greetings,
> >> >>
> >> >> Wout Kremers
> >> >
> >> > --
> >> > ___________________________________
> >> >
> >> > Stefan Roesler
> >> > CERN, SC/RP
> >> > CH-1211 Geneva 23
> >> > Switzerland
> >> >
> >> > Phone: +41-22-7679891
> >> > Fax: +41-22-7669639
> >> > E-mail: Stefan.Roesler_at_cern.ch
> >> >
> >>
> >
> > --
> > ___________________________________
> >
> > Stefan Roesler
> > CERN, SC/RP
> > CH-1211 Geneva 23
> > Switzerland
> >
> > Phone: +41-22-7679891
> > Fax: +41-22-7669639
> > E-mail: Stefan.Roesler_at_cern.ch
> >
>

-- 
___________________________________
Stefan Roesler
CERN, SC/RP
CH-1211 Geneva 23
Switzerland
Phone:  +41-22-7679891
Fax:    +41-22-7669639
E-mail: Stefan.Roesler_at_cern.ch