Water HVL with iodine131

Dear Antonio,

I have checked your input file. Please find here my comments:

  • You have selected DEFAULTs EM-CASCA, which limits the simulation to the EM part. This choice seems appropriate for your objective.

  • You have set a EMF cut for transport of electrons and photons. You have a 1e-06 GeV kinetic energy transport threshold for e-/e+ and 6e-4 GeV for photons. A quick run with your input file yields the usual output file, from where we read: Ecut = 5.1200E-01 MeV, Pcut = 6.0000E-01 MeV. This is correct, because the information refers to the total energy.

  • For I131, many gamma emitted are around hundreds for keV. I read that the most abundant is 364 keV. Your may want to modify your transport thresholds for photons to better consider this.

  • Note that you have set the minimum transport threshold for electrons, as detailed in the Electrons documentation.

You now need a good scoring system to observe the HVL. A post on the forum post contains a few practical hints.

Further material:

I hope this helps.
Best regards,

Tommaso