98-Cf-251

Reaction 0.0253-eV Maxwellian
Average
g-factor Resonance
Integral
14-MeV Fiss. Spec.
Average
total 7.812 (kb) 7.743 (kb) 0.991 5.975 (b) 8.046 (b)
elastic 8.940 (b) 9.132 (b) 1.021 2.737 (b) 4.469 (b)
inelastic ( E-thr = 24.92 keV ) 385.6 (mb) 2.216 (b)
(n,2n) ( E-thr = 5.129 MeV ) 228.9 (mb) 18.69 (mb)
(n,3n) ( E-thr = 11.78 MeV ) 32.11 (mb) 4.256 (μb)
fission 4.939 (kb) 4.895 (kb) 0.991 1.033 (kb) 2.586 (b) 1.280 (b)
(n,fission) 4.939 (kb) 4.895 (kb) 0.991 1.032 (kb) 1.389 (b) 1.269 (b)
(n,n,fiss) ( E-thr = 2.300 MeV ) 1.115 (b) 11.44 (mb)
(n,2n,fiss) ( E-thr = 7.500 MeV ) 84.08 (mb) 16.00 (μb)
(n,4n) ( E-thr = 17.39 MeV ) 522.5e-12 (b)
(n,3nfiss) ( E-thr = 14.50 MeV ) 1.112 (nb)
capture 2.864 (kb) 2.839 (kb) 0.991 518.8 (b) 807.0 (μb) 61.58 (mb)
 
νp 4.100 7.264
νd 5.900e-3 4.060e-3

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)
 .


νp, νd : numbers of prompt and delayed neutrons per fission.