Interpretation of Cross Section of p,n reaction mb or mb/MeV

[flied]

Dear Forum :

I'm reading a cross section data of 20MeV proton + 16O reaction from ICRU 63.
( as attachment and link http://ppt.cc/qf-9 )
The total cross setion of (p,n) reaction is 4.372mb
However, the cross section of emitting neutron of energy between 0 to 1.5MeV is 0.91 mb / MeV.
The cross section of emitting neutron between 1.5 to 2.5 MeV is 2.3 mb / MeV .

But how can the cross section be written as 0.91 or 2.3 mb / MeV, because as 20 MeV proton, it would give a
cross section of 18.2 and 46 mb, which is larger than the total (p,n) reaction
Is it the correct or just the traditional way to present the cross section as mb / MeV ?

 

[mfb]

I think the MeV refers to the neutron energy.
So you have (1.5*0.91)mb for a neutron between 0 and 1.5 MeV (is there a factor 10 missing?).

 

[flied]

thanks mfb,

(1.5*0.91)mb for a neutron between 0 and 1.5 MeV should be correct.
Summation of (1.5*0.91) + 2.3 + 0.75 equals to the total (p,n) reaction cross section.
BTW, which part of factor 10 missing？

 

[mfb]

Oh, I did not see the "-1". 0.91 is fine.

 

[flied]

Thanks a lot