432
8 Nuclear Physics – II
Fig. 8.4 Resonance and
potential sacttering and
absorption cross-sections as a
function of neutron energy
where g =
(2I c + 1)
(2I a + 1)(2I x + 1)
(8.36)
Γ a τ a = ; Γ b τ b =
(8.37)
σ el =
π
k 2
A res + A pot
2
(8.38)
with A res =
iΓ n
(E n − E R ) +
1
2
iΓ
(8.39)
and A pot = exp(2ikR) − 1
(8.40)
Optical model
V = −U − iW
(8.41)
U = vk 1
(8.42)
W =
2
vk
(8.43)
where v =
2E/m
(8.44)
is the velocity of the incident nucleon.
k = (2mE)
1/2
/;
(8.45)
k 1 = [2m(E + U )]
1/2
/
(8.46)
K =
1
λ
=
A σ
vol
=
3σ
4πr
3
0
(8.47)
Direct reactions (Reactions without compound nucleus formation)
1. Inelastic scattering
2. Charge exchange reactions
3. Nucleon transfer reactions
8 Nuclear Physics – II
Fig. 8.4 Resonance and
potential sacttering and
absorption cross-sections as a
function of neutron energy
where g =
(2I c + 1)
(2I a + 1)(2I x + 1)
(8.36)
Γ a τ a = ; Γ b τ b =
(8.37)
σ el =
π
k 2
A res + A pot
2
(8.38)
with A res =
iΓ n
(E n − E R ) +
1
2
iΓ
(8.39)
and A pot = exp(2ikR) − 1
(8.40)
Optical model
V = −U − iW
(8.41)
U = vk 1
(8.42)
W =
2
vk
(8.43)
where v =
2E/m
(8.44)
is the velocity of the incident nucleon.
k = (2mE)
1/2
/;
(8.45)
k 1 = [2m(E + U )]
1/2
/
(8.46)
K =
1
λ
=
A σ
vol
=
3σ
4πr
3
0
(8.47)
Direct reactions (Reactions without compound nucleus formation)
1. Inelastic scattering
2. Charge exchange reactions
3. Nucleon transfer reactions