Re: Total energy deposited by neutrons and protons

From: Alberto Fasso' <>
Date: Wed, 10 Jul 2013 14:53:46 +0200

Dear Saneesh,

the total energy deposited in the medium is what is shown directly
by the results you report:
"The results shows that total energy deposited by all particles
is 5.63121 MeV".

Neutron and proton energies are NOT, as you say, of common origin.
Proton energy deposition is not attributed to the neutron who produced
the proton recoil, it is attributed only to the proton.
Neutron energy deposition (in FLUKA, calculated via kerma factors) is
due to all neutron-produced charged particles (except protons, which are
handled apart). And since in your problem there is boron, a large part
of the neutron energy deposition is due to the alpha and the 7Li particles
emitted in neutron capture by 10B.
Only by chance are the two energies (2.59 and 2.67 MeV) of similar
size (I have cut down on the decimal figures, don't forget that there are
statistical errors).
Their sum is about 5.26 MeV. The total energy (5.63 MeV) is slightly (7%)
larger, because there are also capture gamma rays that you have not
taken into account.


On Wed, 10 Jul 2013, wrote:

> Dear Fluka experts,
> I am trying to calculate the total energy deposited by
> neutron beam having energy 3 MeV in a medium containing
> paraffin and boron by region binning. I have written
> region binning cards for total energy deposited by all
> particles, neutrons and protons.The results shows that
> total energy deposited by all particles is 5.63121 MeV,
> energy deposited by neutron is 2.59293 MeV and the energy
> deposited by proton is 2.671504 MeV.
> The protons are, believed to, recoiled form paraffin or boric acid upon
> neutron collision. Then the maximum possible energy of protons are nothing
> but the energy deposited by neutron beam. But the results shows that
> proton energy is high.
> Also the total energy deposited appears as if neutron and proton
> energies are summed together though they are of common origin. Then
> how to find out the total energy deposited in the medium ? I am
> attaching the input file along with this mail. please help me to
> solve this problem
> Thanks in advance
> Saneesh N
Received on Wed Jul 10 2013 - 18:03:32 CEST

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