Re: LOW ENERGY NEUTRONS

Hi Lawrence,

in your input you have a line:
LOW-BIAS 73. 72. 0.85 BLKBODY @LASTREG 1.0

This command sets a neutron energy cutoff at group 72 (the last group
in the old neutron library). But in the new library group 72 is about
2.7 MeV, and most giant resonance neutrons have lower energies.
I have removed the command and I have got plenty of neutrons.
So, either remove the command, or leave it with a different group
number (e.g. 261 instead of 73), or force FLUKA to use the old
library by means of a LOW-NEUT command.

Best regards,

Alberto

On Tue, 21 Jul 2009, Lawrence Mhatiwa wrote:

>=20
> Dear Fluka Users
>=20
> =A0
>=20
> I am studying=A0 photoneutron processes in targets using FLUKA. In my
> input file I have an electron beam striking a compound target
> (Tungsten and gold) and I am scoring neutron fluence in tungsten, gold
> and lead as shown in the input file.Unfortunately I can not get any
> neutron output yet iam using a 15MeV beam but photoneutrons are
> generally produced from 10MeV onwards in most materials.
>=20
> =A0
>=20
> =A0Can someone please help me to identify what could be wrong with my
> input file?
>=20
> =A0
>=20
> Thank you
>=20
> =A0
>=20
> Lawrence =A0=A0

--=20
Alberto Fasso`
SLAC-RP, MS 48, 2575 Sand Hill Road, Menlo Park CA 94025
Phone: (1 650) 926 4762 Fax: (1 650) 926 3569
fasso_at_slac.stanford.edu
Received on Wed Jul 22 2009 - 20:15:23 CEST