Definition of data found for nuclides in "Cross sections" category under the node "General information / Integral data"
Sig(2200) : This is cross section at 0.0253 eV
Sig(E0) : This is cross section at 0.0253380 eV
This should be equal to Sig(2200), the slight difference come from the fact that
data files were processed at temperature = 293.6 K but INTER take 293.16 K as thermal temperature.
Avg-Sigma : Cross section averaged over a Maxwellian spectrum
Avg-Sigma = integral of sigma(E)*f(E) / integral of f(E) from 1E-5 eV to 20 * E0 (=0.50676 eV)
with f(E) = E/E0*exp(-E/E0)
G-fact : Westcott g-factor
G-fact = Avg-Sigma / Sig(2200)
It's a measure of the deviation from the 1/v cross section behaviour in thermal energy region.
If the cross section varies as a function of 1/v, G-fact = 1.0.
Res Integ : Resonance integral
= integral of sigma(E)/E from 0.5 eV to 100 keV
Sig(fis) : Cross section averaged over a fission spectrum
Sig(fis) = integral of sigma(E)*f(E) / integral of f(E) from 1 keV to 20 MeV
with f(E) = sqrt(E)/Ef^(3/2) * exp(-E/Ef) and Ef = 1.35MeV