Too high (n,n')C* cross section

mosipenk · March 6, 2024, 3:55pm

NeutronHP model for 14 MeV neutron scattering on Carbon gives the deposited energy shown in figure below:

The peak at about 2800 keV is due to much overestimated excitation of the first C12 level at 4.44 MeV. In reality this peak should be at least order of magnitude lower or the events from this peak should be distributed from 0 to 3 MeV like elastic ones. Moreover, the main exclusive channel n+12C–>alpha+Be9 (narrow peak at 8300 keV) is completely missing. Also the 3-apha break-up of C12 is missing here.

Is there some mistake in ENDF files reading by Geant4.11.2.0?

_Geant4 Version:_4.11.2.0
_Operating System:_Ubuntu
_Compiler/Version:_11.4
_CMake Version:_3.22

John_McFee · March 6, 2024, 5:56pm

If you look at the post thread [I can not simulated C12(n,α)Be9 reaction you will see that the 12C(n,alpha) 9Be reaction is represented in the Geant4 data base. The (n,3alpha), however, is absent. That was with Geant4 version 11.0.2

maire · March 7, 2024, 7:02pm

Below, a macro for Hadr03, its printout and the plot of gamma spectrum

mikhail.mac.txt (356 Bytes)

mikhail.out.txt (2.1 KB)