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The method
dEEf
Ef r
Er
1 ) (
,) ( )(
) ,(
The importance of f(E):
Th
t l
i hti f t
t h t fl
t
fl
E
e spec ra we g ng ac or connec s p o on uence o energy uence
at any point of a geometry and hence depends on the actual geometry and
its physical properties.
However, as G increases, and ΔΕ
G
become narrow, the energy group cross sections μ
t,g
,
appro imate the contin o s (E) (E) and do not depend hea il on f(E)
μ
s,g
,
x
u u μ
t
, μ
s
v y
.
This means that generic multi group cross sections (of ΔΕ
G
<<) are used with
analytic
or semi-analytic f(E) appropriate for the problem at hand
.