18-Ar-40

Reaction 0.0253-eV Maxwellian
Average
g-factor Resonance
Integral
14-MeV Fiss. Spec.
Average
total 1.315 (b) 1.400 (b) 1.065 2.291 (b) 2.994 (b)
elastic 655.4 (mb) 739.9 (mb) 1.129 788.0 (mb) 2.569 (b)
inelastic ( E-thr = 1.498 MeV ) 636.2 (mb) 422.7 (mb)
(n,2n) ( E-thr = 10.12 MeV ) 835.7 (mb) 304.1 (μb)
(n,3n) ( E-thr = 16.88 MeV ) 53.87 (nb)
(n,na) ( E-thr = 6.968 MeV ) 2.123 (mb) 1.711 (μb)
(n,np) ( E-thr = 12.84 MeV ) 6.636 (μb) 51.76 (nb)
capture 660.1 (mb) 660.5 (mb) 1.001 293.3 (mb) 346.5 (μb) 1.013 (mb)
(n,p) ( E-thr = 6.885 MeV ) 14.99 (mb) 19.52 (μb)
(n,d) ( E-thr = 10.56 MeV ) 1.949 (mb) 326.5 (nb)
(n,t) ( E-thr = 12.42 MeV ) 354.1 (nb) 1.736 (nb)
(n,He-3) ( E-thr = 15.41 MeV ) 295.7e-15 (b)
(n,a) ( E-thr = 2.548 MeV ) 11.08 (mb) 204.0 (μb)

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)
 .