90-Th-229

Reaction 0.0253-eV Maxwellian
Average
g-factor Resonance
Integral
14-MeV Fiss. Spec.
Average
(n,total) 111.9 (b) 115.4 (b) 1.031 5.840 (b) 7.758 (b)
(n,elastic) 10.43 (b) 11.70 (b) 1.122 2.819 (b) 4.523 (b)
(n,inelastic) ( E-thr = 10.04 eV ) 345.7 (mb) 2.690 (b)
(n,2n) ( E-thr = 5.280 MeV ) 1.717 (b) 33.46 (mb)
(n,3n) ( E-thr = 12.42 MeV ) 92.70 (mb) 23.90 (μb)
(n,fission) 30.92 (b) 30.68 (b) 0.992 315.2 (b) 864.0 (mb) 343.7 (mb)
(n,f) 30.92 (b) 30.68 (b) 0.992 315.0 (b) 294.7 (mb) 338.1 (mb)
(n,nf) ( E-thr = 2.300 MeV ) 438.9 (mb) 5.593 (mb)
(n,2nf) ( E-thr = 7.500 MeV ) 130.6 (mb) 16.08 (μb)
(n,4n) ( E-thr = 17.90 MeV ) 2.735 (nb)
(n,3nf) ( E-thr = 15.50 MeV ) 36.21e-12 (b)
(n,γ) 70.56 (b) 73.04 (b) 1.035 1.313 (kb) 1.193 (mb) 165.6 (mb)

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)
 .