19-K-41

Reaction 0.0253-eV Maxwellian
Average
g-factor Resonance
Integral
14-MeV Fiss. Spec.
Average
total 4.058 (b) 4.394 (b) 1.083 2.084 (b) 2.882 (b)
elastic 2.598 (b) 2.934 (b) 1.129 1.001 (b) 2.526 (b)
inelastic ( E-thr = 1.004 MeV ) 794.2 (mb) 347.6 (mb)
(n,2n) ( E-thr = 10.34 MeV ) 35.38 (mb) 12.15 (μb)
(n,na) ( E-thr = 6.375 MeV ) 131.7 (mb) 379.2 (μb)
(n,np) ( E-thr = 8.001 MeV ) 43.97 (mb) 111.8 (μb)
capture 1.459 (b) 1.460 (b) 1.001 1.581 (b) 17.40 (μb) 5.859 (mb)
(n,p) ( E-thr = 1.752 MeV ) 48.16 (mb) 2.031 (mb)
(n,a) ( E-thr = 114.3 keV ) 29.67 (mb) 931.9 (μb)

These cross sections are calculated from JENDL-4.0 at 300K.
The background color of each cell noted a cross section means the order of the cross-section value.
The unit of cross section, (b), means barns, and SI prefixes are used as following.
(kb) → 103(b),   (mb) → 10−3(b),  (μb) → 10−6(b),  (nb) → 10−9(b).

Maxwellian Average :
σmacs(T) =
2
 
 
π
EU
 
EL
σ(E,T) ⋅ E ⋅ exp (
E
  
kBT
) dE
 
EU
 
EL
E ⋅ exp (
E
  
kBT
) dE
,
where T denotes the temperature, and kB the Boltzmann constant. The upper and lower limits of integration, EL and EU are set to 10−5 eV and 10 eV, respectively.
Resonance Integral :
σri(T) =
EU
 
EL
σ(E,T) ⋅
1
 
E
dE ,
with  EL = 0.5 eV  and  EU = 10 MeV.
U-235 Thermal Fission-Neutron Spectrum Average (Fiss. Spec. Average) :
σfacs(T) =
EU
 
EL
σ(E,T) ⋅
 
4
 
πa3b
⋅ exp (
ab E
     
4 a
) ⋅ sinh
 
bE
dE
 
EU
 
EL
 
4
 
πa3b
⋅ exp (
ab E
     
4 a
) ⋅ sinh
 
bE
dE
,
with  EL = 10−5 eV  and  EU = 20 MeV. The parameters a and b are 0.988 MeV and 2.249 MeV−1, respectively.
Westcott g-factor :
g(T) =
σmacs(T)
 
σ(0.0253 eV,T)
 .