Quote:
Originally Posted by Anthony
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.
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Ah, I know what you're referring to, now. I was still thinking in terms of EM deflection rather than physical materials, which is why I was confused.
My current notes are that this probe's front is covered with some 80 lb/cf wood (geneered from Australian Buloke), a layer 85 cm thick, a total of around 109 g/cm^2. I don't have any notes on the TVT of the particles I'm interested in - in fact, I'm not completely sure it's relevant, as the main purpose of the wood is less to shield the probe, and more to break up the neutral atoms into charged particles for the magshield to fend off. But my instincts there might be wrong; any chance you know the TVT for dissociated protons and electrons with a speed on the order of 0.01c?