1000 Solved Problems in Modern Physics

(Tina Meador) #1

432 8 Nuclear Physics – II


Fig. 8.4Resonance and
potential sacttering and
absorption cross-sections as a
function of neutron energy


whereg=

(2Ic+1)
(2Ia+1)(2Ix+1)

(8.36)

Γaτa=;Γbτb= (8.37)

σel=

π
k^2


∣Ares+Apot


∣^2 (8.38)

withAres=

iΓn
(En−ER)+^12 iΓ

(8.39)

and Apot=exp(2ikR)− 1 (8.40)

Optical model


V=−U−iW (8.41)
U=vk 1 (8.42)

W=



2

vk (8.43)

wherev=


2 E/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

=


vol

=

3 σ
4 πr 03

(8.47)

Direct reactions(Reactions without compound nucleus formation)



  1. Inelastic scattering

  2. Charge exchange reactions

  3. Nucleon transfer reactions

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