Re: ENDRAW

From: John Clem <clem@bartol.udel.edu>
Date: Wed Apr 09 2008 - 13:44:19 CEST

Alberto and Vasilis,

The approach utilizing USDRAW provides a direct means to distinguish proton
recoils from carbon (i.e. other recoils). Exactly what is needed for this
calculation. After incorporating photon yields / propagation and pmt quantum
efficiencies in the result, the overall neutron detection response is
consistent with measurements. Thank you very much for the comments and
suggestions.

best regards,
John

> John Clem
> Research Associate Professor
> Bartol Research Institute
> Department of Physics and Astronomy
> University of Delaware
> Newark, DE 19716 USA
> 302-831-4354

----- Original Message -----
From: "Alberto Fasso'" <fasso@SLAC.Stanford.EDU>
To: <fluka-discuss@fluka.org>
Cc: "John Clem" <clem@bartol.udel.edu>
Sent: Tuesday, April 08, 2008 2:35 PM
Subject: Re: ENDRAW

>I think that John's question was rather how to distinguish proton recoils
> from other recoils when both are deposited as kerma (due to the high
> transport threshold set by him, for whatever reason).
> I am not sure, but I suggest that this could be done by looking at the=20
> secondaries created with code 300 in USDRAW:
> * Icode =3D 30x: call from Kasneu *
> * 300: interaction secondaries *
>
> Those secondaries are stored in COMMON GENSTK:
>
> * /Genstk/ is the storage for secondaries created in hadronic *
> * events *
> * Np =3D total number of secondaries *
> * Kpart (ip) =3D (Paprop) id of the ip_th secondary *
> * Tki (ip) =3D laboratory kinetic energy of ip_th secondary (GeV)*
>
> If an ENDRAW kerma deposition happens just after a proton has been
> generated, I guess that that kerma corresponds to that proton (and it
> could
> be compared to the proton energy (see Kpart above).
>
> Alberto
>
> On Tue, 8 Apr 2008, Vasilis Vlachoudis wrote:
>
>> Dear John,
>>
>> as it is written in the FLUKA manual, during low energy neutron transport
>> only proton recoils are produced from H and N(n,p).
>>
>> "Generation of charged particles
>> Recoil protons and protons from N(n,p) reaction are produced and
>> transported explicitly, taking into account the detailed kinematics
>> of elastic scattering, continuous energy loss with energy straggling,
>> delta ray production, multiple and single scattering."
>>
>> all the rest you will see it as kerma deposition. Not very useful
>> quantit=
> y=20
>> for you since it is the average kinetic energy release to matter per
>> neut=
> ron=20
>> group.
>>
>> Not in the next, but in a following FLUKA release dpa will be included
>> as=
> a=20
>> generalized scoring particle. This will be a quantity of interest for
>> you=
> ,=20
>> since the recoil of Carbon at these energies thought non-ionizing energy
>> =
> loss=20
>> will produce defects in matter. And dpa is related with the energy of
>> th=
> e=20
>> primary knock-on atom.
>>
>> Best Regards
>> Vasilis
>>
>>
>> John Clem wrote:
>>> All,
>>>=20
>>> We are in the process of studying energy deposition of ~2MeV neutrons
>>> in=
> =20
>>> scintillator materials (as a ToF study). In our test case, we setup a=20
>>> rectangular parallelepiped (RPP) 30X30X4cm filled with CH2 ~1g/cm^2 and
>>> =
> the=20
>>> 30x30 surface was illuminated with a perpendicular 2MeV Neutron pencil=
> =20
>>> beam. Threshold for protons are set E>2MeV such that all recoils are=20
>>> reported in ENDRAW as depositions, however I can not find an obviously
>>> w=
> ay=20
>>> to seperate Proton recoils from Carbon in ENDRAW as JTRACK =3D 308
>>> (low=
> =20
>>> energy neutron kerma) is reported for both cases. An alternative of
>>> cour=
> se=20
>>> is the lower the proton threshold so it can be tracked in MGDRAW main,=
> =20
>>> however this will increase the output size (excluding some level of=20
>>> processing inside MGDRAW). Any suggestions ??
>>>=20
>>> Thanks,
>>> John
>>>=20
>>>
>>> John Clem
>>> Research Associate Professor
>>> Bartol Research Institute
>>> Department of Physics and Astronomy
>>> University of Delaware
>>> Newark, DE 19716 USA=3D20
>>> 302-831-4354
>>>
>>>=20
>>
>>
>
> --=20
> Alberto Fass=F2
> SLAC-RP, MS 48, 2575 Sand Hill Road, Menlo Park CA 94025
> Phone: (1 650) 926 4762 Fax: (1 650) 926 3569
> fasso@slac.stanford.edu
> --1334196566-1024129017-1207676104=3D:16479--
>
>
Received on Wed Apr 9 16:03:44 2008

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