RE: [fluka-discuss]: Total efficiency of plastic scientillator

From: Zafar Yasin <Zafar.Yasin_at_cern.ch>
Date: Wed, 12 Oct 2016 15:49:09 +0000

Dear Francesco and FLUKA experts, Thank you for your comment. "No point wise cross sections are available for Carbon in FLUKA", it is not less than a nightmare for us as we have implemented a complex geometry in FLUKA, please see attached, and it took us more than two months. It contains 19 cryomodules, around 40 quadrupoles and 20 plastic scientillators , etc and we want to see their response as beam loss monitors. We first decided to validate/benchmark a simple geometry. In the simple geometry we have only CH but in actual scientillators we have photomultiplier tube portion as well. Is there any other method in FLUKA to calculate total efficiency of these scientillators or so? I have seen a few nice posts related to efficiency from Anna Ferrari, if she can help us or so. Best regards, Zafar ________________________________________ From: Francesco Cerutti Sent: 12 October 2016 12:31 To: Zafar Yasin Cc: fluka-discuss_at_fluka.org Subject: Re: [fluka-discuss]: Total efficiency of plastic scientillator Hi Zafar, you miss the fact that for neutrons below 20 MeV, in the context of the adopted multigroup treatment, you cannot see in the simulation any secondary product (but neutrons and photons) except for few materials where the pointwise treatment can be switched on (this is not the case for carbon in FLUKA2011). Their contribution to energy deposition is anyway taken into account in the kerma approximation (for a fixed neutron energy in a given material this corresponds to a fixed value you will get scored). As a side note, while USRTRACK gives particle fluence differential in particle kinetic energy, USRBIN gives indeed deposited energy, contrary to what you say. Kind regards Francesco ************************************************** Francesco Cerutti CERN-EN/STI CH-1211 Geneva 23 Switzerland tel. ++41 22 7678962 fax ++41 22 7668854 On Wed, 12 Oct 2016, Zafar Yasin wrote: > > Dear FLUKA experts and users, > > > We want to calculate the total efficiency of a plastic scintillator (BC-400), we > have incident isotropic flat beam of neutrons from 1 to 20 MeV (at present we are > first using a single energy). > > We want total efficiency calculated using FLUKA to compare with calculated from > Geant4, plot of efficiency using Geant4 is given below (x-axis is energy of > neutrons in MeV). > > > [IMAGE] > > > > > The total efficiency using Geant4 is calculated as: To calculate the efficiency at > given energy E. It is defined as Eff (E)=Ndet/Nemitted > > Where Nemitted is the number of emitted particle of a given energy E. > > So the efficiency value at single energy 10 MeV is: > > Eff(10 MeV)=1124/5e6 = 2.248e-4 > > Where 1124 are detected particles and 5e6 are emitted particles. > > > My first question is Why we can’t use FLUKA to calculate detector efficiency like > methodology being used in Geant4. > > I was thinking DETECT card is equivalent to pulse height in a detector and can be > used for calculate the efficiency, why it is not applicable for plastic scintillate > as I am not getting the efficiency plot like in Geant4. > > Which scoring cards I should use to calculate total efficiency? USRBIN and USRTRACK > give energy fluence not energy deposited. If I use EVENTBIN, it is difficult for me > to process its output as I never used this card before and if EVENTBIN is like > DETECT, then I will prefer to use DETECT card. > > One way to calculate intrinsic efficiency is I should use USRTRACK to calculate > neutron and proton fluence and then the ratio =proton fluence/neutron fluence give > the intrinsic efficiency and I am not sure is it true or not. If it is intrinsic > efficiency how can I calculate total efficiency. > > > > In summary, I need a efficiency curve like geant4 and how can I do that?.My input > file is attached. > > > Thank you in advance. > > > > Best regards, > > Zafar Yasin > > >


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Received on Wed Oct 12 2016 - 19:36:01 CEST

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