93-Np-238

Reaction 0.0253-eV Maxwellian
Average
g-factor Resonance
Integral
14-MeV Fiss. Spec.
Average
total 2.693 (kb) 2.704 (kb) 1.004 5.903 (b) 7.950 (b)
elastic 12.26 (b) 13.66 (b) 1.115 2.806 (b) 4.418 (b)
inelastic ( E-thr = 26.54 keV ) 380.6 (mb) 2.015 (b)
(n,2n) ( E-thr = 5.512 MeV ) 488.3 (mb) 13.27 (mb)
(n,3n) ( E-thr = 12.12 MeV ) 22.49 (mb) 4.759 (μb)
fission 2.202 (kb) 2.226 (kb) 1.011 1.098 (kb) 2.200 (b) 1.451 (b)
(n,fission) 2.202 (kb) 2.226 (kb) 1.011 1.098 (kb) 1.188 (b) 1.441 (b)
(n,n,fiss) ( E-thr = 3.000 MeV ) 716.0 (mb) 9.416 (mb)
(n,2n,fiss) ( E-thr = 7.500 MeV ) 296.5 (mb) 47.86 (μb)
(n,4n) ( E-thr = 17.88 MeV ) 202.3e-12 (b)
(n,3nfiss) ( E-thr = 14.50 MeV ) 983.8e-12 (b)
capture 479.5 (b) 464.0 (b) 0.968 201.4 (b) 1.131 (mb) 51.40 (mb)
 
νp 2.470 4.510
νd 1.494e-2 1.235e-2

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)
 .


νp, νd : numbers of prompt and delayed neutrons per fission.