I am looking for how to compute the thickness of shielding materials and have found the following research: ISNPS Technical Report ISNPS-1-2013 Tai and El-Genk.doc (unm.edu)
The report is mentions the „highest ionizing energy deposition." I have no idea what it is and how to interpret this data.
"Ionizing energy deposition" is the amount of energy that is lost by a subatomic particle as it passes through some material. The energy lost by the particle is absorbed by the material that it passes through. When you are specifying a radiation shield you want high energy deposition because that means lower energy remaining in the particles, if any, that pass through the shield.
The silicon sphere is a target that is a stand-in for the electronics being protected from radiation by the shield.
The energy deposition concept applies to the sphere: the less energy deposition [in the sphere], the better the shielding must have been.
The article snippet implies that the primary radiation source, external to the shield, can cause secondary emission from the shield material. This secondary emission varies depending on shield materials and thicknesses. For example, with an aluminum shield, thicknesses above 10g/cm^2 have secondary proton emission that the effective dose received by the target sphere is higher.
