Minimum Geometry Length Scale?

Geometry and Materials
1

Hello,

I was wondering, is there a sort of “minimum” length scale for defining geometry in FLUKA? That is, do certain assumptions break down in the physics model if one were to simulate a geometry on the nanoscale? I can imagine that using geometry with dimensions smaller than the deBroglie wavelength of the incident particle would be problematic, but wasn’t sure if the minimum is actually larger, considering that FLUKA’s primary usage is for radiation transport through bulk materials. So I thought it would be good to ask.

To be more concrete: a geometry I was thinking of modeling would involve an array of cylinders with radii on the order of 100 nanometers, irradiated by protons from energies between 120 and 440 GeV. Should I expect difficulties with the physics model, or is it just as capable as it is for the usual length scale of centimeters?

Thanks for your time and help,
Will

3

If I’ve breached forum etiquette with this question, or it is ill-posed in a way that I am missing, please let me know so I can do better for future forum questions.

4

You definitely didn’t. Your question is perfectly legitimate and meaningful, so as to be helpful for other readers too.
On the other hand, your patience is appreciated and helpful too.
The case you indicate (order of 100 nanometers) is at the limit of the code applicability, but still not dramatically beyond.
Previous considerations expand on it (namely the second point, while the nuclear reaction model is not in question).

5

Hi Francesco,

Thank you, this answers my question perfectly! I really appreciate it, and the feedback that there was no problem with the question.