90-Th-227

MT Reaction 0.0253-eV Maxwellian
Average		 g-factor Resonance
Integral		 14-MeV Fiss. Spec.
Average
1 (n,total) 620.1 (b) 623.4 (b) 1.005 − 5.849 (b) 7.400 (b)
2 (n,elastic) 12.53 (b) 14.15 (b) 1.129 − 2.750 (b) 4.544 (b)
4 (n,inelastic) ( E-thr = 9.331 keV ) 444.8 (mb) 2.368 (b)
16 (n,2n) ( E-thr = 5.486 MeV ) 1.898 (b) 27.03 (mb)
17 (n,3n) ( E-thr = 12.70 MeV ) 33.25 (mb) 15.18 (μb)
18 (n,fission) 202.1 (b) 202.2 (b) 1.001 330.5 (b) 722.1 (mb) 297.0 (mb)
19 (n,f) 202.1 (b) 202.2 (b) 1.001 330.4 (b) 277.0 (mb) 294.1 (mb)
20 (n,nf) ( E-thr = 2.700 MeV ) 444.9 (mb) 2.845 (mb)
21 (n,2nf) ( E-thr = 9.500 MeV ) 2.955 (μb) 23.20 (nb)
37 (n,4n) ( E-thr = 18.49 MeV ) − 95.59e-12 (b)
38 (n,3nf) ( E-thr = 17.00 MeV ) − 98.46e-21 (b)
102 (n,γ) 405.2 (b) 405.4 (b) 1.001 661.4 (b) 1.348 (mb) 163.4 (mb)
 
456 νp 2.057 −−− 3.205 −
455 νd 7.690e-3 −−− 5.320e-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).

MT is a number that defines a reaction type. For the relation between MT and reaction type, please see here or refer to the manual of ENDF formats.
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.