DD and DT Fusion Possible?

Physics Processes, Models and Cross Sections
21

Hey James,

Not sure if you have figured this out, but I have also been struggling with this issue for the longest time. You need to download the TENDL datafiles and set/create the G4PARTICLEHP environment variable to the dataset. The physics list you need to use is G4HadronPhysicsQGSP_BIC_AllHP and I also needed to use G4IonPhysicsPHP in order to get this to work.

List of nuclear reactions: 
                deuteron + Deuterium Isotope --> neutron + He3:    3850   Q =   3.271 MeV
              deuteron + Deuterium Isotope --> proton + triton:    3545   Q =  4.0359 MeV
                deuteron + Tritium Isotope --> neutron + alpha:  992605   Q =  17.631 MeV

List of generated particles:
            He3:    3850  Emean =  871.83 keV	( 500.31 keV --> 1.2552 MeV)
          alpha:  992605  Emean =   3.619 MeV	( 2.898 MeV --> 4.3413 MeV)
        neutron:  996455  Emean =  14.081 MeV	( 2.1298 MeV --> 14.847 MeV)
         proton:    3545  Emean =  3.0796 MeV	( 2.6627 MeV --> 3.4997 MeV)
         triton:    3545  Emean =  1.0703 MeV	( 650.22 keV --> 1.4871 MeV)

Thanks,

  • Brendan
22

Hi everyone,

I’m currently working on a simulation involving a neutron source generated by interactions between accelerated deuterons and gaseous deuterium. My goal is to accurately model the nuclear reactions occurring in such a target.

Thanks to this discussion, I am now observing the D(d,n)³He reaction using the QGSP_BIC_AllHP physics list, which is a great step forward.

However, I’m not seeing any deuteron breakup reactions D(d,np)D, which can also contribute to neutron production in these scenarios.

I would like to know if anyone has successfully simulated this type of reaction in Geant4. Are such processes handled by any of the standard physics lists, or is it necessary to implement custom cross sections and explicitly generate the secondary particles to account for these mechanisms?

Any insights or suggestions would be greatly appreciated !

23

Hello all,

Can Geant4 realistically simulate DD and DT fusion (using G4ParticleHP with the TENDL nuclear data library) under magnetic-confinement fusion conditions (e.g., tokamak or stellarator plasmas), where ion energies follow a thermal Maxwellian distribution rather than mono-energetic beams?

Thank you,

Hasan Ghotme

24

It’s not obvious how to configure a Geant4 simulation to do that. On the one hand, you can certainly write your own PrimaryGeneratorAction to generate randomly directed deuterons with a Maxwellian kinetic energy distribution for whatever temperature kT you like.

On the other hand, Geant4 does not do track-track interactions of any kind. If you create a mixed D/T gas, you might be able to specify the temperature as part of the G4Material definition. But it’s not at all obvious that G4 will take that temperature setting into account to compute a kinetic energy for the target nuclei, in order to get the correct cross-sections out of G4TENDL.

This sounds like an excellent project for you to attempt, and report back here if you are successful, or if you run into specific configuration questions along the way.

25

But it’s not at all obvious that G4 will take that temperature setting into account to compute a kinetic energy for the target nuclei, in order to get the correct cross-sections out of G4TENDL.

Actually it does, if you look at the method G4Nucleus::GetBiasedThermalNucleus you will see that the tempeture of the material is taking into account to select target nucleus kinematic. This method is called during physicals process of course but also during cross-section computation by the method G4ParticleHPThermalBoost::GetThermalEnergy.

1 Like
26

I don’t know what the situation is, but my G4TENDL1.4 does not include DD reaction cross sections, which forced me to directly customize a reaction function.