Re: Radiation weighting factor for neutrons

[Scott Schwahn <schwahn@jlab.org>]

Perhaps the largest reason is that the neutron interaction in flesh at the
lower neutron energies is dominated by the moderation/thermal absorption
reactions.  From a dose equivalent standpoint, the 2.2 MeV gamma from
hydrogen capture is the most important one.  Near the surface of the body,
the N-14 (n,p) reaction is more effective in delivering equivalent dose than
the (n,g) on hydrogen.  As the neutron energy continues to rise, the
moderation/thermal absorption reaction decreases, as the neutrons are
scattered out of the body, lowering the overall radiation weighting factor
(W_r).  As the neutron energy increases yet more, the reactions are dominated
by scattering and spallation mechanisms and the dE/dx of the scattered
particles.

Best regards,
Scott

Sunil C Nair wrote:

> ...Why high
> energy neutrons has less QF ?

--
Scott O. Schwahn, CHP
Thomas Jefferson National Accelerator Facility
schwahn@jlab.org


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