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Gamma-ray shielding against bursters
I'm a little dubious about the figure "need to burrow up to 3 kilometers below the surface before the incoming flux would drop to 1% of its initial value. "

Earth's atmosphere cuts cosmic ray and gamma ray fluxes to just about 0. Or, specifically, background ionizing radiation dose on Earth at sea level is about .000001 R/hour.

Unless you're delivering so much energy as to ablate and move the shielding material (like a weapons-grade laser), the number of gamma rays and cosmic rays doesn't matter when determining shielding thickness requirements. What matters is the energy of the individual rays.

Gamma ray bursts don't generate rays particularly more energetic than the ones that hammer Earth every day. Frankly, distant gamma ray bursts are probably the source of some of the stuff pounding Earth every day. Water cuts their dose in half for every 7cm of water; a 7-meter water shield reduces that by a factor of 2^100. The atmosphere does the same as about 2.8m of water.

It's just bloody weird to say "1% will still get through 3km of rock."
Mike Miller, Materials Engineer

"Everbody's always in favor of saving Hitler's brain, but when you put it in the body of a great white shark, oh, suddenly you've gone too far." -- Professor Farnsworth, Futurama

Messages In This Thread
RE: Gamm-ray shielding against bursters - by Rynn - 11-11-2016, 06:20 AM
RE: Gamma-ray shielding against bursters - by Cray - 11-12-2016, 02:30 AM

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