19-K-39

MT Reaction 0.0253-eV Maxwellian
Average
g-factor Resonance
Integral
14-MeV Fiss. Spec.
Average
1 (n,total) 4.192 (b) 4.463 (b) 1.065 2.014 (b) 2.815 (b)
2 (n,elastic) 2.089 (b) 2.359 (b) 1.129 955.9 (mb) 2.605 (b)
4 (n,inelastic) ( E-thr = 2.588 MeV ) 102.8 (mb) 52.07 (mb)
16 (n,2n) ( E-thr = 13.42 MeV ) 1.631 (mb) 492.6 (nb)
22 (n,na) ( E-thr = 7.404 MeV ) 75.52 (mb) 22.26 (μb)
28 (n,np) ( E-thr = 6.545 MeV ) 235.3 (mb) 775.4 (μb)
102 (n,γ) 2.098 (b) 2.099 (b) 1.001 1.081 (b) 7.416 (μb) 2.680 (mb)
103 (n,p) 0.000 (b) 0.000 (b) 493.3 (mb) 385.3 (mb) 113.3 (mb)
107 (n,a) 4.302 (mb) 4.374 (mb) 1.017 291.9 (mb) 256.4 (mb) 41.06 (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).

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)
 .