Author Topic: Electromagnetic Radiation Shield?  (Read 2373 times)

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Electromagnetic Radiation Shield?
« on: 10/05/2006 07:22 PM »
I'm curious - is any serious work being done on the idea of an electromagnetic radiation shield, for either a lunar outpost or Mars mission?  I've read a few older things on the web, but nothing recent.  Does anyone know of any current projects?

Offline ch1le

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RE: Electromagnetic Radiation Shield?
« Reply #1 on: 10/05/2006 07:45 PM »
I have also thought about this same thing and i have come to the conclusion that it needs a shitload (sorry) of Juice! Might work on the moon with those nuclear plants. And mby in the future on fusion powered ships! :) But thats sci-fi as far as this "half" century goes

Offline mauk2

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Re: Electromagnetic Radiation Shield?
« Reply #2 on: 10/05/2006 08:39 PM »
Rad shielding is a very complex topic.

Passive shielding is fairly simple: Pile up a screaming ton of anything and you're done.  Some rad shields used with particle accelerators are up to 44 feet of reinforced concrete, and bioshields in commercial nuclear reactors run around 15 feet.

Once we go to the moon for real, the simple way to provide shielding is to live in a hole.  Not glamorous, but there's a lot to be said for caves.  :)

For lightweight shielding, it gets much more complex.

There are basically only three "classes" of radiation hazards:  Charged particles, neutral particles, and photons.  "Active" electromagnetic shields might provide a lightweight way of protecting against charged particles.   Neutral particles in space are rare since neutrons decay into protons after only 15 minutes or so.  Photons are, to my knowledge, unstoppable by any proposed method except the "pile up stuff" plan.  The way to lower photon exposure (gammas and x-rays) is to have high energy orbits and get from point A to point B as fast as possible.

All solutions for radiation shielding are very, very heavy, or power intensive, or both.  Fortunately, large masses of propellant can theoretically be arranged to serve as rad shields, and since you have to carry the stuff anyway....  :)

Hope that clears some stuff up for ya! :)

http://www.space.com/businesstechnology/technology/rad_shield_040527.html

http://www.space.com/businesstechnology/lunarshield_techwed_050112.html

http://www.islandone.org/Settlements/MagShield.html

As a note, the permitted exposure limits for astronauts are HUGE.  Much, much higher than for nuclear powerplant workers, for example.  But oddly enough, the same limits astronauts have used to be valid for everybody! :)

http://www-tech.mit.edu/Bulletins/Radiation/rad5.txt

Fortunately for our plans to move out into space, adult humans are far more rad-tolerant than we are generally given credit for.   Being really fat helps, too!  :)

Here's a good paper about "space weather,"  also known as radiation:

http://www.srl.utu.fi/Chapman/presentations/friday/04.turner.pdf

Notice that acute doses up to 35 centigray are labeled as "not impacting."  

Wow.

http://lsda.jsc.nasa.gov/books/apollo/S2ch3.htm

Note that good paper on rad effects.  Going past the Van Allen belts without a "storm cellar" is inherently risky.  While the 360 rad dose described in that paper from a solar storm would not have instantly killed the astronauts, that much of the shine is not healthy.


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