Date: Wed, 7 Aug 2013 10:56:34 +0800
Dear FLUKA experts,
Sorry I forgot to attache the figure and input card. Thanks in advance.
Best regards,
Yung-Shun Yeh
On Tue, Aug 6, 2013 at 12:23 PM, Yung-Shun Yeh <adair.py94g_at_nctu.edu.tw>wrote:
> Dear FLUKA experts,
>
> I am studying the cosmic-ray muon induced neutron in underground
> laboratory, and would like to ask you how to retrieve neutron information
> using mgdraw.f user-defined function.
>
> To calculate the detection efficiencies of muon-induced neutron, I try to
> generate a set of neutron samples according the mean muon energy in our
> laboratory. I would like to reproduce the results in PhysRevD.64.013012.
> The simulation setup is that mono-energy energetic muon beam injects into
> the liquid scintillator. The liquid scintillator is C10H22 filled in a
> cylinder with height 4500cm and radius 500cm. I use mgdraw.f to retrieve
> the properties of neutron produced during the muon propagating. For
> neutron-indcued neutron case, highest energy neutron is treated as parent
> particle, and avoided double count.
>
> I plot the neutron energy spectra. For high energy neutron(>20MeV), the
> neutron spectrum looks well comparing with the paper, but for low energy
> part below 10MeV, there are two spikes around 9MeV and 0.4MeV, which I
> think abnormal ones. The PRD paper did not show the low energy behavior, so
> I am unable to do a comparison. Please see the figure. The x axis is in GeV.
>
> I read the manual, and learnt for low energy neutron with energy<20MeV,
> FLUKA deals with neutrons as group algorithm, but mgdraw.f deals with
> neutrons particle by particle. I also noticed in the previous discussion,
> it is not suggested to use mgdraw.f to get information of low energy
> neutrons.
> http://www.fluka.org/web_archive/earchive/new-fluka-discuss/0807.html
>
> My question is: how do I modify mgdraw.f to get correct information of low
> energy neutron? Or is there a alternative way?
>
> Regards,
> Yung-Shun Yeh
>
>
(image/png attachment: genKE.png)
- application/octet-stream attachment: DayaBayMuon.inp
- application/octet-stream attachment: mgdraw.f