Simulation of radiation damage

Good day,

I am an MSc student and a fairly new user to FLUKA, I would really appreciate any input you have to offer. I am aiming to simulate radiation damage in certain materials for example the dpa induced by an electron beam of 1 MeV on a disk of Al2O3, which is 1mm thick and 1cm in diameter.

Attached is a sample flair input card I am using to simulate this process is there anything I have omitted that I could add to make my simulation as accurate as possible or any oversight a more experienced user could point out.

Or if there are any comments in general I would really appeciate any input.
1MeV_Electrons_Al203_dpa.inp (2.0 KB)

Hello @cbaldwin ,

Since you don’t have a specific question on the simulation you are trying to run, I can only give you some very general recommendations:

When you are new to FLUKA I would recommend to do your study step by step, adding complexity and checking how changing or adding cards affect your result. For this, make sure that for the beam parameters and USRBINs you defined you already have a resolved and statistically converged output for visualisation, as for example also discussed here or here.

Then, the most important is to figure out what physical interactions are taking place for a 1 MeV electron beam on a (relatively light) and thin target material. Since all particles, including any produced secondary particles can contribute to non-ionizing energy loss and by consequence to DPA, you need to wonder if the PRECISIOn DEFAULTs you set in your input card allow you to be as accurate as you want. At the energy you are looking at, displacements will most probably be mainly caused by direct Coulomb interactions. As explained in this lecture, you can set the production and transport thresholds for particles in the electromagnetic sector which could be important for your results. As also mentioned in this post, residual interaction due to electro- or photonuclear interactions should be negligible.

Be reminded that in a Monte Carlo approach, the damage threshold is an averaged quantity which does not take into account any realistic crystal lattice inside the (compound) material. You can check how sensitive your result is to this 30 eV threshold you set by varying it up or down as suggested here.

Let me know in case you run into trouble somewhere or if anything is unclear.