Answer:
elastic partial width is 2.49 eV
Explanation:
given data
ER Â E = 250 eV
spin J = 0
cross-section magnitude σ = 1300 barns
peak P = 20ev
to find out
elastic partial width W
solution
we know here that
σ = λ²× W /  ( E × π × P )   ...................1
put here all value
σ = (0.286)² × W  × [tex]10^{-16}[/tex]/  ( 250 × π × 20 )
1300 × [tex]10^{-24}[/tex] = (0.286)² × W  × [tex]10^{-16}[/tex]/  ( 250 × π × 20 )
solve it and we get W
W = 249.56 × [tex]10^{-2}[/tex]
so elastic partial width is 2.49 eV