4th Nuclear Physics Assignment Yaser Gholami USYD 25/05/12
Q.1
Therefore
so
is given
M = 30
so we have :
we can actually workout the energy level :
Looking at the NNDC : we can tell that the three low-energy groups crosspond to the first three 2+ excited states.
..
check it with the NNDC:
Q.2
to show it's monenergtic we have to show that
now to show D-D reaction gives a monoenergitic neutron we have to show
calculating the
from the reaction using
that means for a monoenergitc neutron
must be very small.so
Or in another word if we look at : and therefor
which is called cold plasma .
we know that
,
Q.3 a) The absorption coefficient:
given that
b) The effective cross-section inbarns, assuming that the absorption is totally due to hydrogen (which is true because the absorption cross-section of oxygen is very small compared to hydrogen.
finding the R for Hyderogen effective cross-section = C) The thickness of water needed to reduce the flux to one-tenth and to one hundredth.:
d. The mean free path for thermal neutrons in water
Explain briefly and clearly whether it is ever possible to use neutrons from 14C(p,n)14N to produce the inverse reaction 14N (n,p)14C in another target. these are two reaction that we are looking at :
and
are spinless and the condition for inverse reaction for these two reactions
is if the cross-section which
is just the reverse reaction from the equation :
Therefore we
use neutrons from 14C(p,n)14N to produce the inverse reaction 14N(n,p)14C in another target.