Neutron production from a 5 MeV proton beam on a beryllium target

Physics Processes, Models and Cross Sections
1

Hi,

I am trying to generate neutrons from bombarding a 5 MeV proton beam on a beryllium target.
I have tried many different physics lists such as FTFP_BERT, QGSP_BERT, and QBBC, etc.

None of the lists gives me good enough neutron kinematics compared with measurements. In particular, with a 1 mA proton beam on beryllium, I am expecting 3e12 neutrons.
However, I only get 1/4 neutron flux with the QBBC physics list, which is already the list with the most generated neutrons.

Would experts here recommend a physics list, or an example for me to generate neutrons that best match measurements?

Thanks,
Shih-Kai.

2

Hello!

May be you will find this review of physics lists helpful:
https://geant4.web.cern.ch/node/155
Pay special attention to lists with the “_HP” at the end, which indicates using a high precision neutron package.
Note: physics lists with _HP consume a lot more CP-time. For example, in my special case one event with QGSP_BERT generated approximately ten times faster then with QGSP_BERT_HP

3

You may use G4QGSP_BIC_AllHP, with the AllHP option you will get the neutron production from the ENDF/B-VII.1 database. See for example https://www.oecd-nea.org/janisweb/book/protons/

4

Here, a run of example Hadr03, with G4HadronPhysics_BIC_AllHP (see PhysicsList.cc)
You need to have G4TENDL1.3.2 installed.

shihkai.mac.txt (285 Bytes)
shihkai.out.txt (2.5 KB)