99-Es-255

MT Reaction 0.0253-eV Maxwellian
Average
g-factor Resonance
Integral
14-MeV Fiss. Spec.
Average
1 (n,total) 64.90 (b) 66.70 (b) 1.028 6.015 (b) 8.277 (b)
2 (n,elastic) 9.319 (b) 10.53 (b) 1.130 2.843 (b) 4.678 (b)
4 (n,inelastic) ( E-thr = 46.58 keV ) 308.5 (mb) 2.721 (b)
16 (n,2n) ( E-thr = 5.998 MeV ) 511.7 (mb) 8.922 (mb)
17 (n,3n) ( E-thr = 11.11 MeV ) 286.3 (mb) 43.05 (μb)
18 (n,fission) 500.4 (mb) 502.9 (mb) 1.005 2.922 (b) 2.060 (b) 703.5 (mb)
19 (n,f) 500.4 (mb) 502.9 (mb) 1.005 2.467 (b) 919.6 (mb) 680.8 (mb)
20 (n,nf) ( E-thr = 2.100 MeV ) 1.046 (b) 22.75 (mb)
21 (n,2nf) ( E-thr = 8.500 MeV ) 94.07 (mb) 13.32 (μb)
37 (n,4n) ( E-thr = 17.49 MeV ) 814.3e-12 (b)
38 (n,3nf) ( E-thr = 13.50 MeV ) 691.6e-18 (b) 27.01 (nb)
102 (n,γ) 55.00 (b) 55.43 (b) 1.008 1.386 (kb) 897.7 (μb) 163.6 (mb)
 
456 νp 3.866 7.366
455 νd 8.776e-3 5.999e-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).

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)
 .


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