39-Y-91

MT Reaction 0.0253-eV Maxwellian
Average
g-factor Resonance
Integral
14-MeV Fiss. Spec.
Average
1 (n,total) 7.149 (b) 7.904 (b) 1.106 3.879 (b) 5.532 (b)
2 (n,elastic) 5.732 (b) 6.472 (b) 1.129 2.141 (b) 4.220 (b)
4 (n,inelastic) ( E-thr = 561.7 keV ) 249.8 (mb) 1.287 (b)
16 (n,2n) ( E-thr = 8.017 MeV ) 1.464 (b) 3.202 (mb)
17 (n,3n) ( E-thr = 14.95 MeV ) 1.246 (μb)
22 (n,na) ( E-thr = 4.218 MeV ) 282.9 (μb) 72.44 (nb)
28 (n,np) ( E-thr = 7.778 MeV ) 4.049 (mb) 873.7 (nb)
32 (n,nd) ( E-thr = 13.42 MeV ) 0.000 (b) 582.6e-12 (b)
102 (n,γ) 1.401 (b) 1.401 (b) 1.001 3.766 (b) 766.8 (μb) 20.23 (mb)
103 (n,p) ( E-thr = 1.939 MeV ) 13.24 (mb) 20.18 (μb)
104 (n,d) ( E-thr = 5.528 MeV ) 971.1 (μb) 210.8 (nb)
105 (n,t) ( E-thr = 7.092 MeV ) 19.69 (μb) 8.776 (nb)
106 (n,He-3) ( E-thr = 11.62 MeV ) 0.000 (b) 6.827e-15 (b)
107 (n,a) 0.000 (b) 0.000 (b) 166.8 (μb) 3.534 (mb) 7.869 (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).

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)
 .