Quote:
Originally Posted by DataPacRat
I'm not quite sure what you mean by that; could you elaborate?
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Basically, the way it works is:
High energy particles and gamma rays have an average penetration, and undergo exponential decay (reduce intensity by a factor of e for every multiple of the average, or by a factor of 2 for ever 0.69* that average, or by a factor of 10 for every 2.3* that average). This value depends somewhat on energy.
Moderate energy charged particles do not undergo exponential decay -- they just lose energy at a fairly consistent rate and eventually stop. In the process they produce secondary radiation, which works the same way as gamma rays, but if you choose your shielding material properly the secondary radiation doesn't have a lot of penetration.
If you have 100g/cm^2 of shielding and the stuff you're shielding against is gamma with a tenth-value-thickness of 50g/cm^2, you have PF 100. If it has a TVT of 20 g/cm^2 you have PF 100,000. If it has a TVT of 10g/cm^2 you have PF 10,000,000,000.