/sci/ - Science & Math

[Anonymous No.12774317]

How thick would a layer of cement need to be to reduce radiation to about what you'd get at sea level?

[Anonymous No.12774347]

in space or what?

[Anonymous No.12774364]

>>12774317
https://what-if.xkcd.com/29/
This comic is about water, but water is actually fairly similar to concrete for radiation blocking abilities.

[Anonymous No.12774379]

>>12774347
Yes. I forgot to say "in space" and now feel stupid.

>>12774364
>For the kinds of radiation coming off spent nuclear fuel, every 7 centimeters of water cuts the amount of radiation in half.
Thanks, but that's the only line I really found relevant.

[Anonymous No.12774407]

>>12774379
https://www.quora.com/How-thick-of-lead-would-I-need-to-add-to-the-walls-and-roof-of-a-shelter-to-make-it-radiation-proof-against-a-nuclear-bomb-attack
Maybe this one is better. It talks about thickness for fallout/nuclear shelters

[Anonymous No.12774635]

>>12774407
>To cut fallout gamma rays by half 0.5 inches of lead is equal to 0.7 inches of steel, or 2.2 inches of concrete, or 3.3 inches of earth.
This is pretty good, but I think my real issue is not knowing how much radiation there is in any given region of space. Increasing thickness by X amount reduces the radiation by half, but if I don't have any idea how much radiation there is to begin with then it doesn't mean dick.

[Anonymous No.12774778]

>>12774317
depends what you put in the cement.

[Anonymous No.12774889]

>>12774635

https://www.nasa.gov/mission_pages/sdo/science/Solar%20Irradiance.html

I think it will depend on how far you are from the sun and what is occluding the radiation. Radiation follows the inverse square law so it decreases a lot the further away you are.

You might be able to approximate it with insolation measured in watts/m^2 and see how much earth surface gets vs earth orbit. The atmosphere/ionosphere blocks parts of the suns radiation but not each part evenly— blocks a lot of uv light which is why pilots get cataracts more than the average person. Mars gets 590 watts/m^2 and earth surface gets 1000. I think the low earth orbit gets about 1400.

[Anonymous No.12774912]

>>12774889
Irradiance is photons, but what you need to shield against is ionizing radiation. If you’re not near the earth or Jupiter, the main concern will be cosmic rays and CMEs

[Anonymous No.12774917]

>>12774912