20-Ca-40

MT Reaction 0.0253-eV Maxwellian
Average
g-factor Resonance
Integral
14-MeV Fiss. Spec.
Average
1 (n,total) 3.469 (b) 3.864 (b) 1.114 2.153 (b) 2.880 (b)
2 (n,elastic) 3.061 (b) 3.456 (b) 1.129 993.8 (mb) 2.701 (b)
4 (n,inelastic) ( E-thr = 3.437 MeV ) 243.0 (mb) 37.44 (mb)
16 (n,2n) ( E-thr = 16.04 MeV ) 4.088 (nb)
22 (n,na) ( E-thr = 7.217 MeV ) 44.03 (mb) 7.920 (μb)
28 (n,np) ( E-thr = 8.538 MeV ) 484.5 (mb) 213.4 (μb)
102 (n,γ) 407.6 (mb) 407.8 (mb) 1.001 212.8 (mb) 506.2 (μb) 1.387 (mb)
103 (n,p) ( E-thr = 542.4 keV ) 236.4 (mb) 98.61 (mb)
107 (n,a) 0.000 (b) 0.000 (b) 256.8 (mb) 150.4 (mb) 41.59 (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)
 .