93-Np-235

Reaction 0.0253-eV Maxwellian
Average
g-factor Resonance
Integral
14-MeV Fiss. Spec.
Average
total 219.5 (b) 224.2 (b) 1.021 5.884 (b) 7.889 (b)
elastic 11.32 (b) 12.79 (b) 1.130 2.810 (b) 4.471 (b)
inelastic ( E-thr = 34.38 keV ) 325.5 (mb) 1.081 (b)
(n,2n) ( E-thr = 7.013 MeV ) 293.0 (mb) 677.1 (μb)
(n,3n) ( E-thr = 13.10 MeV ) 412.9 (μb) 375.1 (nb)
fission 53.02 (b) 53.78 (b) 1.014 302.6 (b) 2.452 (b) 2.203 (b)
(n,fission) 53.02 (b) 53.78 (b) 1.014 302.3 (b) 1.590 (b) 2.188 (b)
(n,n,fiss) ( E-thr = 2.300 MeV ) 852.7 (mb) 14.78 (mb)
(n,2n,fiss) ( E-thr = 10.00 MeV ) 10.70 (mb) 3.153 (μb)
(n,3nfiss) ( E-thr = 13.50 MeV ) 9.425e-12 (b) 12.73 (nb)
capture 155.1 (b) 157.2 (b) 1.014 813.7 (b) 1.298 (mb) 129.7 (mb)
 
νp 2.632 4.591
νd 4.850e-3 4.317e-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).

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.